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Balbharti Maharashtra State Board 11th Biology Important Questions Chapter 15 Excretion and Osmoregulation Important Questions and Answers.

Maharashtra State Board 11th Biology Important Questions Chapter 15 Excretion and Osmoregulation

Question 1.
What are metabolic waste products?
Answer:
Metabolism produces a variety of by-products, some of which need to be eliminated. Such by-products are called metabolic waste products.

Question 2.
Define excretion.
Answer:
The process of eliminating waste products from the body is called excretion.

Question 3.
Where are metabolic wastes produced?
Answer:
Metabolic wastes are produced inside body cells.

Question 4.
Enlist the various excretory products produced in the human body.
Answer:
The various excretory products produced by the human body are as follows:

1. Fluids such as water; gaseous wastes like CO₂; nitrogenous wastes like ammonia, urea and uric acid, creatinine; minerals; salts of sodium, potassium, calcium, etc. if present in body in excess are excreted through urine, faeces and sweat.
2. Pigments formed due to breakdown of haemoglobin like bilirubin (excreted through faeces) and urochrome (eliminated through urine).
3. The pigments present in consumed foodstuffs like beet root or excess of vitamins, hormones and drugs.
4. Volatile substances present in spices (eliminated through lungs).

Question 5.
Write a note on deamination.
Answer:

1. Deamination is the process of breakdown of excess amino acids.
2. It is an essential process, since the body of an organism is unable to store excess amino acids.
3. In this process, amino group is separated from the amino acid and ammonia is formed.
4. Toxic ammonia is either excreted or converted to less toxic forms like urea or uric acid before excretion.

Question 6.
Availability of water plays a key role in deciding the mode of excretion of an organism. Justify.
Answer:

1. Ammonia is the basic product of deamination process.
2. Ammonia is highly toxic and needs to be diluted immediately.
3. If there is no or limited access to water, need for conversion of ammonia becomes necessary.
   Hence, the availability of water plays a key role in deciding the mode of excretion of an organism.

Question 7.
What are the three main modes of excretion in animals?
Answer:
The three main modes of excretion in animals are as follows:
i. Ammonotelism
ii. Ureotelism
iii. Uricotelism

1. Ammonotelism:
   • Elimination of nitrogenous wastes in the form of ammonia is called as ammonotelism.
   • Ammonia is basic in nature and hence it can disturb the pH of the body, if not eliminated immediately.
   • Any change in pH would disturb all enzyme catalyzed reactions in the body and would also make the plasma membrane unstable.
   • Ammonia is readily soluble in water and needs large quantity of water to dilute and reduce its toxicity.
   • This is however an energy saving mechanism of excretion and hence all animals that have plenty of water available for dilution of ammonia, excrete nitrogenous wastes in the form of ammonia.
   • Animals that follow this mode of excretion are known as ammonotelic animals.
   • 1 gm ammonia needs about 300 – 500 ml of water for elimination.
   • Ammonotelic animals excrete ammonia through general body surface (skin), gills and kidneys.
     e.g. Ammonotelism is found in aquatic invertebrates, bony fishes, and aquatic / larval amphibians. Animals without excretory system (Protozoa) are also ammonotelic.
2. Ureotelism:
   • Elimination of nitrogenous wastes in the form of urea is called as ureotelism.
   • Urea is comparatively less toxic and less water-soluble than ammonia. Hence, it can be concentrated to some extent in body.
   • The body requires less water for elimination.
   • Since it is less toxic and less water soluble, ureotelism is suitable for animals that need to conserve water to some extent. Hence, ureotelism is common in terrestrial animals, as they have to conserve water.
   • It takes about 50 ml H2O for removal of 1 gm NH2 in form of urea.
   • Ureotelic animals generally convert ammonia to urea in the liver by operating ornithine / urea cycle in which 3 ATP molecules are used to produce one molecule of urea.
     e.g. Mammals, cartilaginous fishes (sharks and rays), many aquatic reptiles, most of the adult amphibians, etc. are ureotelic.
3. Uricotelism:
   • Elimination of nitrogenous wastes in the form of uric acid is called as uricotelism.
   • Uric acid is least toxic and hence, it can be retained in the body for some time in concentrated form.
   • It is least soluble in water. Hence there is minimum (about 5 – 10 ml for 1 gm) or no need of water for its elimination.
   • Those animals which need to conserve more water follow uricotelism. However, these animals need to spend more energy.
   • Ammonia is converted into uric acid by ‘inosinic acid pathway’ in the liver of birds, e.g. Birds, some insects, many reptiles, land snails, are uricotelic.

Question 8.
Fill in the blanks:
i. ________ is the basic product of deamination process.
ii. Aquatic amphibians excrete nitrogenous waste in the form of _______.
iii. Uricotelic organisms, convert ammonia to urea in the _______ by operating _____ cycle.
iv. Ammonia is converted into uric acid by ______ pathway in birds.
Answer:
i. Ammonia
ii. Ammonia
iii. liver, omithine/urea
iv. inosinic acid

Question 9.
Explain the following sentences,
i. Humans are ureotelic.
Answer:

• Urea is comparatively less toxic and less water – soluble than ammonia. Hence, it can be concentrated to some extent in the body.
• The body requires less water for elimination of urea.
  c. Due to these properties, ureotelism is suitable for animals which need to conserve water to some extent.
  Thus, humans are ureotelic.

ii. Sharks retain more urea in their blood.
Answer:

• Sharks retain more urea in their body fluid (blood) to make their blood isotonic to surrounding marine water (in order to maintain osmotic balance).
• This helps them to prevent possible loss of water by exosmosis.

Question 10.
Distinguish between Ureotelism and Uricotelism.
Answer:

No.	Ureotelism	Uricotelism
i.	It is the elimination of nitrogenous waste in the form of urea.	It is the elimination of nitrogenous waste in the form of uric acid.
ii.	Excretion of urea requires less (moderate ) amount of water.	Excretion of uric acid requires negligible amount of water.
iii.	Removal of 1 gm of urea requires 50 ml of water.	Removal of 1 gm of uric acid requires 5 – 10 ml of water, j
iv.	Urea is less toxic.	Uric acid is least toxic.
e.g.	It is generally seen in terrestrial animals. Mammals, cartilaginous fishes (sharks and rays), many aquatic reptiles, most adult amphibians, etc.	It is seen in birds, some insects, many reptiles, land snails, etc.

Question 11.
Distinguish between Ammonotelism and Uricotelism.
Answer:

No.	Ammonotelism	Uricotelism
i.	It is the elimination of nitrogenous waste in the form of ammonia.	It is the elimination of nitrogenous waste in the form of uric acid.
ii.	Excretion of ammonia requires plenty of water.	Excretion of uric acid requires negligible amount of water.
iii.	Removal of 1 gm of ammonia requires 300 – 500 ml of water.	Removal of 1 gm of uric acid requires 10ml of water.
iv.	Ammonia is very toxic.	Uric acid is less toxic.
e.g.	It is found in aquatic invertebrates, bony fishes and aquatic/ larval amphibians, etc.	It is seen in birds, some insects, many reptiles, land snails, etc.

Question 12.
Terrestrial animals are generally either ureotelic or uricotelic, not ammonotelic. Why?
Answer:

1. Ammonia is highly toxic to animals.
2. An animal requires large amount of water to dissolve and eliminate ammonia.
3. Terrestrial animals cannot lose such a large amount of water.
4. Ureotelic and uricotelic animals require less amount of water for removal of nitrogenous waste. Hence, to conserve water, ureotelism and uricotelism is adapted by terrestrial animals.

Question 13.
What is plasma creatinine? Why is it used as an index of kidney function?
Answer:

1. Plasma creatinine is produced from catabolism of creatinine phosphate during skeletal muscle contraction.
2. It provides a ready source of high energy phosphate.
3. Normally blood creatinine levels remain steady because the rate of production matches its excretion in urine.
4. Hence, plasma creatinine is used as an index of kidney function and its level above normal is an indication of poor renal function.
   [Note: Plasma creatinine is a waste product produced by muscles from the breakdown of a compound called ‘creatine phosphate.]

Question 14.
How can excretion play a role in homeostasis?
Answer:

1. Homeostasis is the maintenance of constant internal environment of the body.
2. Homeostasis is however dependent on osmoregulation, which is the process of controlling solute concentrations and water balance.
3. The composition of blood and therefore the internal environment is highly dependent on what the excretory organs retain in the body.
   Hence, excretion plays an important role in homeostasis.

Question 15.
How do different organisms carry out excretion?
Answer:
Different organisms carry out excretion in the following manner:

1. Unicellular organisms have contractile vacuoles which collect and discharge waste products outside the cell.
2. Excretion in sponges takes place by diffusion of waste material in water. This waste is discharged through the osculum.
3. True organs of excretion are found in those animals that show bilateral symmetry.
4. The most common type of excretory organ is a simple or branching tube that opens to the exterior, through pores called nephridiopores. This system is generally found in some annelids, Amphioxus, earthworms, etc.
5. In most of the insects, excretion takes place by a set of blind ended tubules called malpighian tubules.
6. Crustaceans have green glands as excretory organs.
7. Members of phylum Echinodermata do not have any specialised excretory organs. Waste materials directly diffuse into water or are excreted through tube feet.
8. The mammalian kidneys are a collection of functional units called nephrons, which are well designed to excrete metabolic waste.

Question 16.
What are nephridia? Explain the major types of nephridia in detail.
Answer:
Nephridia are simple or branching tubules used for excretion which open to the exterior through pores called nephridiopores.
Two major types of nephridia are as follows:
i. Protonephridia:
These are network of dead end tubes called flame cells. They are mostly found in animals that lack a true body cavity, e.g. Platyhelminthes, rotifers, some annelids and Amphioxus.

ii. Metanephridia:
These are unbranched coiled tubes that are connected to the body cavity through funnel like structures called nephrostomes. Body fluid enters the nephridium through nephrostome and gets discharged ‘ through nephridiopore. e.g. Earthworms.

Question 17.
Distinguish between the Ureter and Urethra.
Answer:

No.	Ureter	Urethra
i.	Ureters are two duct-like structures arising from the hilum of the kidney.	Urethra is a single tube-like structure arising from the urinary bladder.
ii.	Ureter carries urine from the kidney to the urinary bladder.	Urethra carries urine from the urinary bladder to the exterior of the body.
iii.	Ureters are paired structures.	Urethra is unpaired structure.

Question 18.
Write a short note on micturition.
Answer:

1. The process of release of urine from the urinary bladder is called micturition.
2. The average capacity of urinary bladder is 700 ml.
3. When urinary bladder is almost half filled, stretch receptors in urinary bladder transmit impulses to spinal cord, initiating a conscious desire to expel urine.
4. Micturition reflex center of spinal cord transmit impulses to the wall of urinary bladder and internal urethral sphincter.
5. Bladder muscles contract and muscles of internal urethral sphincter relax.
6. The external sphincter receives impulses from conscious centre of brain and relaxes.
7. This leads to elimination of urine from the bladder.

Question 19.
Explain the L.S of kidney with a neat and labelled diagram.
Answer:

1. Each kidney is covered by three layers of tissue, namely the outermost renal fascia, middle adipose capsule and innermost renal capsule.
   • The outermost layer, renal fascia is made up of a thin layer of fibrous connective tissue. It anchors the kidney to the abdominal wall as well as surrounding tissue.
   • The middle layer is a mass of fatty tissue called adipose capsule. It protects the kidneys by shock absorption.
   • The innermost layer, renal capsule is a smooth transparent fibrous membrane that is continuous with outer layer of ureters. It acts as a barrier against spread of infections in kidney.
2. The L.S. of kidney shows two distinct regions within the capsule. Histologically, kidney is divisible into two regions as renal cortex and renal medulla.
   • Renal cortex is the outer / peripheral, red coloured and granular region. It contains Malpighian bodies, convoluted tubules and blood vessels.
   • Medulla is inner region of kidney with pale red colour and striated appearance. Medulla mainly consists of Loops of Henle and collecting ducts. All these are arranged in conical manner to form renal pyramids.
   • Cortex extends in medulla as columns of Bertini / renal columns between pyramids. Narrow tip of pyramid is called as renal papilla. There are several pyramids.
   • Renal papilla open into the minor calyx. Minor calyces merge together to form major calyces and major calyces unite together to form renal pelvis.
   • Renal pelvis (renal sinus) is funnel-shaped area in the region of medulla of kidney. Renal pelvis
     

Question 20.
What is nephrology?
Answer:
Nephrology is branch of biology that deals with the structure, function and disorders of male and female urinary system.

Question 21.
Write a note on nephron.
Answer:

1. Nephrons are structural and functional units of kidney.
2. Each nephron consists of a 4 – 6 cm long, thin-walled tube called the renal tubule and a bunch of capillaries known as the glomerulus.
3. The wall of the renal tubule is made up of a single layer of epithelial cells.
4. Its proximal end is wide, blind, cup-like and is called as Bowman’s capsule, whereas the distal end is open.
5. The nephron is divisible into Bowman’s capsule, neck, proximal convoluted tubule (PCT), Loop of Henle (LoH), distal convoluted tubule (DCT) and collecting tubule (CT).
6. The glomerulus is present in the cup-like cavity of Bowman’s capsule and both are collectively known as renal corpuscle or Malpighian body.

Question 22.
With the help of a well labelled diagram, describe the structure of nephron.
Answer:
Nephron is the structural and functional unit of kidney.
Structure of nephron:
A nephron (uriniferous tubule) is a thin walled, coiled duct, lined by a single layer of epithelial cells. Each nephron is divided into two main parts:
i. Malpighian body
ii. Renal tubule

i. Malpighian body: Each Malpighian body is about 200pm in diameter and consists of a Bowman’s capsule and glomerulus.
a. Glomerulus:
Glomerulus is a bunch of fine blood capillaries located in the cavity of Bowman’s capsule.
A small terminal branch of the renal artery, called as afferent arteriole enters the cup cavity (Bowman capsule) and undergoes extensive fine branching to form network of several capillaries. This bunch is called as glomerulus.
The capillary wall is fenestrated (perforated).
All capillaries reunite and form an efferent arteriole that leaves the cup cavity.
The diameter of the afferent arteriole is greater than the efferent arteriole. This creates a high hydrostatic pressure essential for ultrafiltration, in the glomerulus.

b. Bowman’s capsule:
It is a cup-like structure having double walls composed of squamous epithelium.
The outer wall is called as parietal wall and the inner wall is called as visceral wall.
The parietal wall is thin consisting of simple squamous epithelium.
There is a space called as capsular space / urinary space in between two walls.
Visceral wall consists of special type of squamous cells called podocytes having a foot-like pedicel. These podocytes are in close contact with the walls of capillaries of glomerulus.
There are small slits called as filtration slits in between adjacent podocytes.

ii. Renal tubule:
a. Neck:
The Bowman’s capsule continues into the neck. The wall of neck is made up of ciliated epithelium. The lumen of the neck is called the urinary pole. The neck leads to proximal convoluted tubule.

b. Proximal Convoluted Tubule :
This is highly coiled part of nephron which is lined by cuboidal cells with brush border (microvilli) and surrounded by peritubular capillaries. Selective reabsorption occurs in PCT. Due to convolutions (coiling), filtrate flows slowly and remains in the PCT for longer duration, ensuring that maximum amount of useful molecules are reabsorbed.

c. Loop of Henle :
This is ‘U’ shaped tube consisting of descending and ascending limb.
The descending limb is thin walled and permeable to water and lined with simple squamous epithelium.
The ascending limb is thick walled and impermeable to water and is lined with simple cuboidal epithelium.
The LoH is surrounded by capillaries called vasa recta.
Its function is to operate counter current system – a mechanism for osmoregulation.
The ascending limb of Henle’s loop leads to DCT.

d. Distal convoluted tubule:
This is another coiled part of the nephron.
Its wall consists of simple cuboidal epithelium.
DCT performs tubular secretion / augmentation / active secretion in which, wastes are taken up from surrounding capillaries and secreted into passing urine.
DCT helps in water reabsorption and regulation of pH of body fluids.

e. Collecting tubule:
This is a short, straight part of the DCT which reabsorbs water and secretes protons.
The collecting tubule opens into the collecting duct.

Question 23.
What is the difference between Cortical nephrons and Juxtamedullary nephrons.
Answer:

	Cortical nephrons	Juxtamedullary nephrons
i.	They have a shorter loop of Henle.	They have a longer loop of Henle.
ii.	Loop of Henle of these nephrons extends very little into the medulla.	Loop of Henle of these nephrons run deep into the medulla.
iii.	Most nephrons are cortical nephrons.	Few nephrons are juxtamedullary nephrons.
iv.	Efferent arteriole forms peritubular capillary network around DCT, PCT and Henle’s loop of cortical nephrons	Efferent arteriole forms loop-shaped vasa recta around  Henle’s loop of juxtamedullary nephrons.

Question 24.
Sketch and label Malpighian body.
Answer:

Question 25.
What are podocytes? In which part of the nephron are they present?
Answer:
Podocytes are a special type of squamous cells that have a foot-like pedicel. They are present in the visceral wall of the Bowman’s capsule and are in close contact with the walls of capillaries of glomerulus

Question 26.
Write a short note on Juxta Glomerular Apparatus.
Answer:

1. Some smooth muscle cells of the wall of afferent arteriole are modified in such a way that their sarcoplasm is granular. These cells are called juxtaglomerular (JG) cells.
2. In each nephron, initial part of DCT makes contact with the afferent arteriole of same nephron.
3. Cells in the wall of DCT in this region are packed more densely than those in other region of DCT. This is called macula densa.
4. Macula densa and the JG cells together form Juxta Glomerular Apparatus (JGA).
5. The JGA plays an important role in blood pressure regulation within the kidney.

Question 27.
Explain the mechanism of urine formation in detail.
Answer:
Process of urine formation is completed in three steps, namely;
i. Ultrafiltration/ Glomerular filtration,
ii. Selective reabsorption,
iii. Tubular secretion / Augmentation

i. Ultrafiltration / Glomerular filtration :
Diameter of afferent arteriole is greater than the efferent arteriole. The diameter of capillaries is still smaller than both arterioles. Due to the difference in diameter, blood flows with greater pressure through the glomerulus. This is called as glomerular hydrostatic pressure (GHP) and normally, it is about 55 mmHg. GIIP is opposed by osmotic pressure of blood (normally, about 30 mm Hg) and capsular pressure (normally, about 15 mm Hg).

Hence net / effective filtration pressure (EFP) is 10 mm Hg.
EFP = Hydrostatic pressure in glomerulus – (Osmotic pressure of blood + Filtrate Hydrostatic pressure)
= 55 – (30 +15)
= 10 mm Hg

Under the effect of high pressure, the thin walls of the capillary become permeable to major components of blood (except blood cells and macromolecules like protein).
Thus, plasma except proteins oozes out through wall of capillaries.
About 600 ml blood passes through each kidney per minute.

The blood (plasma) flowing through kidney (glomeruli) is filtered as glomerular filtrate, at a rate of 125 ml / min. (180 L/d).

Glomerular filtrate / deproteinized plasma / primary urine is alkaline, contains urea, amino acids, glucose, pigments, and inorganic ions.

Glomerular filtrate passes through filtration slits into capsular space and then reaches the proximal convoluted tubule.

ii. Selective reabsorption :
Selective reabsorption occurs in proximal convoluted tubule (PCT). It is highly coiled so that glomerular filtrate passes through it very slowly. Columnar cells of PCT are provided with microvilli due to which absorptive area increases enormously.

This makes the process of reabsorption very effective.
These cells perform active (ATP mediated) and passive (simple diffusion) reabsorption.
Substances with considerable importance (high threshold) like – glucose, amino acids, vitamin C, Ca⁺⁺, K⁺, Na⁺, Cl^– are absorbed actively, against the concentration gradient. Low threshold substances like water, sulphates, nitrates, etc., are absorbed passively.
In this way, about 99% of glomerular filtrate is reabsorbed in PCT and DCT.

iii. Tubular secretion / Augmentation :
Finally filtrate reaches the distal convoluted tubule via loop of Henle. Peritubular capillaries surround DCT. Cells of distal convoluted tubule and collecting tubule actively absorb the wastes like creatinine and ions like K⁺, H⁺ from peritubular capillaries and secrete them into the lumen of DCT and CT, thereby augmenting the concentration of urine and changing its pH from alkaline to acidic.

Secretion of H⁺ ions in DCT and CT is an important homeostatic mechanism for pH regulation of blood. Tubular secretion is the only process of excretion in marine bony fishes and desert amphibians.

Question 28.
Marine bony fishes and desert amphibians rely on which process of excretion?
Answer:
Tubular secretion

Question 29.
Where does selective reabsorption of glomerular filtrate take place?
Answer:
Selective reabsorption of glomerular filtrate takes place in the proximal convoluted tubule (PCT).

Question 30.
What is glomerular filtration pressure or net effective filtration pressure?
Answer:
Glomerular filtration pressure (GFP)/ Effective filtration pressure (EFP) is the difference between the hydrostatic pressure (GHP) and the sum of osmotic pressure of blood and capsular pressure (CHP).
It can be represented as:
EFP = Glomerular hydrostatic pressure – (Osmotic pressure of blood + Filtrate Flydrostatic pressure)
= 55 – (30 + 15)
= 10 mmHg
[Note: Net filtration pressure = Glomerular blood hydrostatic pressure – (Capsular hydrostatic pressure + Blood colloid osmotic pressure)
Source: Tort or a, G., Derrickson, B. Principles of Anatomy and Physiology. 11^th Edition.]

Question 31.
Distinguish between Selective reabsorption and Tubular secretion.
Answer:

No.	Selective rcabsorption	Tubular secretion
i.	Selective reabsorption is concerned with the selective absorption of useful substances from the glomerular filtrate.	Tubular secretion is transfer of materials from peritubular capillaries to the renal tubular lumen.
ii.	Substances with considerable importance (high threshold) like – glucose, amino acids, vitamin C, Ca++, K+, Na+, Cl– are absorbed actively, against concentration gradient	In this process, substances like urea. amino acids, glucose, pigments, and inorganic ions arc removed from the blood and discharged along with the urine.
iii.	Selective reabsorption occurs in Proximal convoluted tubule, Henle’s loop, Distal convoluted tubule and collecting duct.	Tubular secretion occurs in Distal convoluted tubules only.

Question 32.
Explain the process of concentration of urine in deai1.
OR
Explain counter current mechanism in detail.
Answer:
Under the conditions like low water intake or high water loss due to sweating, humans can produce concentrated urine. This urine can be concentrated around four times i.e. 1200 mOsm/L, than the blood (300 mOsm/L). hence, a mechanism called countercurrent mechanism is operated in the human kidneys. The countercurrent mechanism operating in the Limbs of Henle’s loop of juxtamedullarv nephrons and vasa recta is as follows:
i. It involves the passage of fluid from descending to ascending limb of Henle’s loop.

ii. This mechanism is called countercurrent mechanism, since the flow of tubular fluid is in opposite direction through both limbs.

iii. In case of the vasa recta, blood flows from ascending to descending parts of itself.

iv. Wall of descending limb is thin and permeable to water, hence, water diffuses from tubular fluid into tissue fluid due to which, tubular fluid becomes concentrated.
v. The ascending limb is thick and impermeable to water. Its cells can reabsorb Na⁺ and Cl^– from tubular fluid and release into tissue fluid.

vi. Due to this, tissue fluid around descending limb becomes concentrated. This makes more water to move out from descending limb into tissue fluid by osmosis.

vii. Thus, as tubular fluid passes down through descending limb, its osmolarity (concentration) increases gradually due to water loss and on the other hand, progressively decreases due to Na⁺ and Cl^– secretion as it flows up through ascending limb.

viii. Whenever retention of water is necessary, the pituitary secretes ADH. ADH makes the cells in the wall of collecting ducts permeable to water.

ix. Due to this, water moves from tubular fluid into tissue fluid, making the urine concentrated.

x. Cells in the wall of deep medullar part of collecting ducts are permeable to urea. As concentrated urine flows through it, urea diffuses from urine into tissue fluid and from tissue fluid into the tubular fluid flowing through thin ascending limb of Henle’s loop.

xi. This urea cannot pass out from tubular fluid while flowing through thick segment of ascending limb, DCT and cortical portion of collecting duct due to impermeability for it in these regions.

xii. However, while flowing through collecting duct, water reabsorption is operated under the influence of ADII. Due to this, urea concentration increases in the tubular fluid and same urea again diffuses into tissue fluid in deep medullar region.

xiii. Thus, same urea is transferred between segments of renal tubule and tissue fluid of inner medulla. This is called urea recycling; operated for more and more water reabsorption from tubular fluid and thereby excreting small volumes of concentrated urine.

xiv. Osmotic gradient is essential in the renal medulla for water reabsorption by counter current multiplier system.

xv. This osmotic gradient is maintained by vasa recta by operating counter current exchange system.

xvi. Vasa recta also have descending and ascending limbs. Blood that enters the descending limb of the vasa recta has normal osmolarity of about 300 mOsm/L.

xvii. As it flows down in the region of renal medulla where tissue fluid becomes increasingly concentrated, Na⁺, Cl^– and urea molecules diffuse from tissue fluid into blood and water diffuse from blood into tissue fluid.

xviii. Due to this, blood becomes more concentrated which now flows through ascending part of vasa recta. This part runs through such region of medulla where tissue fluid is less concentrated.

xix. Due to this, Na⁺, Cl^– and urea molecules diffuse from blood to tissue fluid and water from tissue fluid to blood. This mechanism helps to maintain the osmotic gradient.

Question 33.
Camel excretes concentrated urine. Give reason.
Answer:
In order to reabsorb water to maximum capacity, loop of Henle is longer in desert mammals like camel. Hence, camel excretes concentrated urine.

Question 34.
Why is urine yellow in colour?
Answer:
Normal urine is pale yellow coloured transparent liquid, due to the pigment urochrome.

Question 35.
How is the composition of urine regulated?
Answer:
The composition of urine depends upon food and fluid consumed by an individual. There are two ways in which it the composition is regulated. They are as follows:

1. Regulating water reabsorption through ADH
2. Electrolyte reabsorption though RAAS
3. Atrial Natriuretic Peptide

i) Regulating water reabsorption through ADH:
Hypothalamus in the midbrain has special receptors called osmoreceptors which can detect change in osmolarity (measure of total number of dissolved particles per liter of solution) of blood.

If osmolarity of blood increases due to water loss from the body (after eating namkeen or due to sweating), osmoreceptors trigger release of Antidiuretic hormone (ADH) from neurohypophysis (posterior pituitary). ADH stimulates reabsorption of water from last part of DCT and entire collecting duct by increasing the permeability of cells.

This leads to reduction in urine volume and decrease in osmolarity of blood.

Once the osmolarity of blood comes to normal, activity of osmoreceptor cells decreases leading to decrease in ADH secretion. This is called negative feedback.

In case of hemorrhage or severe dehydration too, osmoreceptors stimulate ADH secretion. ADH is important in regulating water balance through kidneys.

In absence of ADH, diuresis (dilution of urine) takes place and person tends to excrete large amount of dilute urine. This condition called as diabetes insipidus.
[Note: Hypothalamus is a part of forebrain]

ii) Electrolyte reabsorption through RAAS:
Another regulatory mechanism is RAAS (Renin Angiotensin Aldosterone System) by Juxta Glomerular Apparatus (JGA).

Whenever blood supply (due to change in blood pressure or blood volume) to afferent arteriole decreases (e.g. low BP/dehydration), JGA cells release Renin. Renin converts angiotensinogen secreted by hepatocytes in liver to Angiotensin I. ‘Angiotensin converting enzyme’ further modifies Angiotensin I to Angiotensin II, the active form of hormone. It stimulates adrenal cortex to release another hormone called aldosterone that stimulates DCT and collecting ducts to reabsorb more Na and water, thereby increasing blood volume and pressure.

iii) Atrial natriuretic peptide (ANP):
A large increase in blood volume and pressure stimulates atrial wall to produce atrial natriuretic peptide (ANP). ANP inhibits Na+ and Cl reabsorption from collecting ducts inhibits release of renin, reduces aldosterone and ADH release too. This leads to a condition called Natriuresis (increased excretion of Na+ in urine) and diuresis.

Question 36.
What is renin? Give its function.
Answer:
Renin is an enzyme secreted by juxtaglomerular cells of afferent arteriole.
Function: It activates Angiotensinogen to Angiotensin-I.

Question 37.
What is the function of Angiotensin II?
Answer:
Functions of Angiotensin II:

1. It constricts arterioles in kidney thereby reducing blood flow and increasing blood pressure.
2. It stimulates PCT cells to enhance reabsorption of Na⁺, Cl^– and water.
3. It stimulates adrenal cortex to release another hormone called aldosterone that stimulates DCT and collecting ducts to reabsorb more Na and water, thereby increasing blood volume and pressure.

Question 38.
Which hormones and factors are involved in regulation of kidney function?
Answer:
Hormones like ADH, Renin, Angiotensin and Atrial Natriuretic Peptide (ANP) are involved in regulation of kidney function.

Question 39.
Can improper kidney function lead to brittle bones? Justify your answer.
Answer:
Yes, improper kidney function lead to brittle bones.

1. Kidneys participate in synthesis of calcitriol, the active form of Vitamin D which is needed for absorption of dietary calcium.
2. Deficiency of calcitriol can lead to brittle bones.

Question 40.
Do organs other than kidney participate in excretion? Explain.
Answer:
Yes, various organs other than the kidney participate in excretion. They are as follows:
i. Skin:
Skin acts as an accessory excretory organ. The skin of many organisms is thin and permeable. It helps in diffusion of waste products like ammonia.
Human skin however is thick and impermeable. It shows presence of two types of glands namely, sweat glands and sebaceous glands.
a. Sweat glands are distributed all over the skin. They are abundant in the palm and facial regions. These simple, unbranched, coiled, tubular glands open on the surface of the skin through an opening called sweat pore. Sweat is primarily produced for thermoregulation but it also excretes substances like water, NaCl, lactic acid and urea.
b. Sebaceous glands are present at the neck of hair follicles. They secrete oily substance called sebum. It forms a lubricating layer on skin making it softer. It protects skin from infection and injury.

ii. Lungs:
Lungs are the accessory excretory organs. They help in excretion of volatile substances like C02 and water vapour produced during cellular respiration. Along with CO₂, lungs also remove excess of H₂O in the form of vapours during expiration. They also excrete volatile substances present in spices and other food stuff.

Question 41.
Enlist the human excretory organs and their excretory products.
Answer:
Excretory OrgAnswer:

1. Lungs: Remove CO₂ and also water vapour to a considerable extent. Volatile substances present in spices and other food stuff are excreted through lungs
2. Kidneys: Remove nitrogenous waste products like ammonia, urea and uric acid, creatinine. They also remove excessive amount of water, salts and certain minerals.
3. Skin: Remove water, NaCl, lactic acid and urea by through of sweat.

Question 42.
What is albuminaria? What are its causes?
Answer:

• Albuminaria is the presence of excess albumin in the urine.
• Causes: Injury to the endothelial capsular membrane as a result of increased blood pressure, injury or irritation of kidney cells by substances such as toxins or heavy metals.

Question 43.
A patient report indicates presence of excessive quantities of ketone bodies in the urine. What does this indicate? How is it caused?
Answer:
Presence of excessive quantities of ketone bodies in the urine indicates that the patient is suffering from diabetes mellitus, starvation or too little carbohydrates in the diet.

Question 44.
Sheela is suffering from kidney infection. Presence of which type of cells in the urine can be indicative of this?
Answer:
Presence of leucocytes in the urine can be indicative of infection of kidney or other urinary organs.

Question 45.
Enlist the various disorders and diseases related to the excretory system.
Answer:
Some disorders and diseases related to the excretory system are as follows:

1. Kidney stones
2. Uremia
3. Nephritis
4. Renal Failure
5. Ketonuria
6. Albuminaria

Question 46.
Write a note on kidney stones with reference to types, symptoms and diagnosis.
Answer:
Kidney stones are also called renal calculi. They may be formed in any portion of urinary tract, from kidney tubules to external opening.
Types:
Depending on their composition, kidney stones are classified into the following types.

1. Calcium stones : These are usually calcium oxalate or calcium phosphate stones.
2. Struvite stones : These are formed in response to bacterial infection caused by urea – splitting bacteria. They grow in size quickly and become quite large.
3. Uric acid stones : These stones usually affect people drinking less water or consuming high protein diet.
4. Cystine stones : It is a genetic disorder that causes the kidney to excrete too much of certain amino acid.

Symptoms:
Intermittent pain below rib cage in back and side ways. Hazy, brownish/reddish/ pinkish urine. Frequent urge to pass urine. Pain during micturition.

Diagnosis:
Uric acid content of blood, colour of urine, kidney X-ray, sonography of kidney are different diagnostic tests prescribed depending on symptoms.

Question 47.
What is uremia?
Answer:
If the level of urea in blood rises above 0.05%, the condition is known as uremia. It may lead to kidney failure.

Question 48.
What is the normal content of urea in blood?
Answer:
The normal content of urea in blood is 0.01 to 0.03 %.

Question 49.
Write a note on nephritis.
Answer:

1. Nephritis is the inflammation of kidneys characterised by proteinuria.
2. It is caused due to increased permeability of glomerular capsular membrane, permitting large amounts of proteins to escape from blood to urine.
3. This leads to change in blood colloidal osmotic pressure, leading to movement of fluid from blood to interstitial spaces.
4. It is reflected as edema.

Question 50.
What is renal failure? Describe its types.
Answer:
Renal failure is the decrease or cessation of glomerular filtration and ¡s classified into two types.
i) Acute Renal failure (ARF):
ARF is sudden worsening of renal function that most commonly happens after severe bleeding. There is a decrease in urine output (oligouriaf scanty urine i.e., less than 400 mi/day or less than 0.5 ml/kg/li in children). Other causes of ARF may include acute obstruction of both ureters or nephrotoxic drugs. ARF can be detected biochemically by elevated serum creatinine levels.

ii) Chronic kidney disease (CKD) :
It is the progressive and generally irreversible decline in glomerular filtration rate (GFR). It may be caused due to chronic glomerulonephritis. It can be detected by reduced kidney size and possibility of anaemia.

Question 51.
When does a patient need to undergo haemodialysis? Explain the process in detail.
Answer:

1. When renal function of a person falls below 5 – 7 %, accumulation of harmful substances in blood begins. In such a condition, the person has to go for artificial means of filtration of blood i.e. haemodialysis.
2. In haemodialysis, a dialysis machine is used to filter blood. The blood is filtered outside the body using a dialysis unit.
3. In this procedure, the patients’ blood is removed; generally from the radial artery and passed through a cellophane tube that acts as a semipermeable membrane.
4. The tube is immersed in a fluid called dialysate which is isosmotic to normal blood plasma. Hence, only excess salts if present in plasma pass through the cellophane tube into the dialysate.
5. Waste substances being absent in the dialysate, move from blood into the dialyzing fluid.
6. Filtered blood is returned to vein.
7. In this process it is essential that anticoagulant like heparin is added to the blood while it passing through the tube and before resending it into the circulation, adequate amount of anti-heparin is mixed.
8. Also, the blood has to move slowly through the tube and hence the process is slow.

Question 52.
Write a note on peritoneal dialysis.
Answer:

1. In this method, the dialyzing fluid is introduced in abdominal cavity or peritoneal cavity.
2. The peritoneal membrane acts as semipermeable dialyzing membrane.
3. Toxic wastes and extra solutes pass into the fluid.
4. This fluid is drained out after a prescribed period of time.
5. Peritoneal dialysis can be repeated as per the need of the patient.
6. It can be carried out at home at work or while travelling. But it is not as efficient as haemodialysis.

Question 53.
What are the drawbacks of haemodialysis?
Answer:

• Kidneys are associated with secretion of erythropoietin, renin and calcitriol which is not possible using dialysis machine.
• During dialysis, the blood has to move slowly through the tube and hence the process is slow.

Question 54.
What is kidney transplant?
Answer:

1. It is the organ transplant of a healthy kidney into a patient with end – stage renal disease.
2. Kidney transplantation is classified as cadaveric (deceased donor) or living donor kidney transplant.
3. Living donor kidney transplant are further classified as genetically related (living-related) or non-related (living non-related) transplants.

Question 55.
Complete the diagram / chart with correct labels / information. Write the conceptual details regarding it.
i)

Answer:

Skin:
Skin acts as an accessory excretory organ. The skin of many organisms is thin and permeable. It helps in diffusion of waste products like ammonia.
Human skin however is thick and impermeable. It shows presence of two types of glands namely, sweat glands and sebaceous glands.
a. Sweat glands are distributed all over the skin.
They are abundant in the palm and facial regions. These simple, unbranched, coiled, tubular glands open on the surface of the skin through an opening called sweat pore. Sweat is primarily produced for thermoregulation but it also excretes substances like water, NaCI, lactic acid and urea.

b. Sebaceous glands are present at the neck of hair follicles.
They secrete oily substance called sebum. It forms a Lubricating layer on skin making it softer. It protects skin from infection and injury.

ii)

Answer:

1. In this method, the dialyzing fluid is introduced in abdominal cavity or peritoneal cavity.
2. The peritoneal membrane acts as semipermeable dialyzing membrane.
3. Toxic wastes and extra solutes pass into the fluid.
4. This tluid is drained out after a prescribed period of time.
5. Peritoneal dialysis can be repeated as per the need of the patient.
6. It can be carried out at home at work or while travelling. But it is not as efficient as haemodialysis.

Question 55.
Invertebrates, bony fishes, tadpoles, etc. are ammonotelic. Whereas birds, reptiles, land snails, etc. are uricotelic. What would be the probable reason for the difference in mode of excretion?
i. Ammonotelic organisms conserve water as conversion of ammonia to uric acid requires large amount of water.
ii. Elimination of ammonia requires large quantity of water, thus ammonotelism is seen in aquatic animals.
iii. Uricotelic organisms require moderate water for eliminating urea and formation of ammonia requires expenditure of energy. Thus, to conserve water and energy, these animals have uricotelism mode of excretion.
iv. Aquatic animals can retain ammonia and store it in the body for long time.
(A) i and iii
(B) only ii
(C) only iv
(D) ii and iii
Answer:
(B)

Question 56.
A lab technician was evaluating blood reports of some patients. She observed the following values of the report:

Sr. No.	Patient	Comments on urine/ blood report
i.	A	High levels of glucose in urine
ii.	B	Presence of excess quantities of ketone in urine
iii.	C	Presence of leucocytes in urine
iv.	D	0.06% urea in blood
V.	E	High level of proteins in blood

Read the given comments and discuss what disorder/disease the patient must be suffering from.

Answer:

Sr. No.	Patient	Comments on urine/ blood report	Disorder/ Disease
i.	A	High levels of glucose in urine	Glucosuria
ii.	B	Presence of excess quantities of ketone in urine	Ketonuria (Indicative of diabetes mellitus)
iii.	C	Presence of leucocytes in urine	Infection of kidney or urinary organs
iv.	D	0.06% urea in blood	Uremia
V.	E	High level of proteins in blood	Proteinuria/ Nephritis

Multiple Choice Questions

Question 1.
Uric acid is the main nitrogenous waste in
(A) birds
(B) cartilaginous fish
(C) mammals
(D) larval amphibians
Answer:
(A) birds

Question 2.
Protonephridia is the excretory organ of
(A) platyhelminthes
(B) coelenterates
(C) arthropods
(D) aschelminthes
Answer:
(A) platyhelminthes

Question 3.
The glomerulus receives blood through the
(A) vasa recta
(B) renal artery
(C) afferent arteriole
(D) efferent arteriole
Answer:
(C) afferent arteriole

Question 4.
More ADH results in
(A) reduced permeability of DCT
(B) dilute urine
(C) reduced blood pressure
(D) concentrated urine
Answer:
(D) concentrated urine

Competitive Corner

Question 1.
Match the items in Column-I with those in Column-II [NEET Odisha 2019]

	Column-I		Column-II
i.	Podocytes	a.	Crystallised oxalates
ii.	Protonephridia	b.	Annelids
iii.	Nephridia	c.	Amphioxus
iv.	Renal calculi	d.	Filtration slits

Select the correct option from the following:
(A) i-d, ii-b, iii-c, iv-a
(B) i-c, ii-d, iiii-b, iv-a
(C) i-c, ii-b, iii-d, iv-a
(D) i-d, ii-c, iii-b, iv-a
Answer:
(D) i-d, ii-c, iii-b, iv-a

Question 2.
Match the following parts of a nephron with their function: [NEET Odisha 2019]

i.	Descending limb of Henle’s loop	a.	Reabsorption of salts only
ii.	Proximal convoluted tubule	b.	Reabsorption of water only
iii.	Ascending limb of Henle’s loop	c.	Conditional reabsorption of sodium ions and water
iv.	Distal convoluted tubule	d.	Reabsorption of ions, water and organic nutrients

Select the correct option from the following:
(A) i-d, ii-a, iii-c, iv-b
(B) i-a, ii-c, iii-b, iv-d
(C) i-b, ii-d, iii-a, iv-c
(D) i-a, ii-d, iii-b, iv-c
Answer:
(C) i-b, ii-d, iii-a, iv-c

Question 3.
Which of the following factors is responsible for the formation of concentrated urine? [NEET(UG) 2019]
(A) Secretion of erythropoietin by Juxtaglomerular complex.
(B) Hydrostatic pressure during glomerular filtration.
(C) Low levels of antidiuretic hormone.
(D) Maintaining hyperosmolarity towards inner medullary interstitium in the kidneys.
Answer:
(D) Maintaining hyperosmolarity towards inner medullary interstitium in the kidneys.

Question 4.
Portions of renal cortex, which are projected into renal medulla, among the renal pyramids are called as _______. [MHT CET 2019]
(A) Columns of Bertini
(B) Columnae Camae
(C) Ampullae
(D) Ducts of Bellini
Answer:
(A) Columns of Bertini

Question 5.
Renal failure is typically detected by biochemical analysis of blood which shows _______. [MHT CET 2019]
(A) increased level of amino acids
(B) lower level of uric acid
(C) lower level of serum creatinine
(D) higher level of serum creatinine
Answer:
(D) higher level of serum creatinine

Question 6.
Which of the following statements is CORRECT with reference to nephron? [MHT CET 2019]
(A) ADH hormone increases permeability of PCT cells to reabsorb water.
(B) Efferent arteriole forms peritubular network all around tubule.
(C) Podocytes occur in ascending limb of loop of Henle.
(D) Descending limb of Henle’s loop is impenneable to water.
Answer:
(B) Efferent arteriole forms peritubular network all around tubule.

Question 7.
Match the items given in Column I with those in Column li and select the correct option given below. [NFET (UG) 2018]

	Column I (Function)		Column II (Part of excretory system)
i.	Ultrafiltration	a.	Henle’s loop
ii.	Concentration of urine	b.	Ureter
iii.	Transport of urine	c.	Urinary bladder
iv.	Storage of urine	d.	Malpighian corpuscle
v.		e.	Proximal convoluted tubule

(A) i-e, ii-d, iii-a, iv-b
(B) i-d, ii-a, iii-b, iv-c
(C) i-d, ii-e, iii-b, iv-c
(D) i-e, ii-d, iii-a, iv-c
Answer:
(B) i-d, ii-a, iii-b, iv-c

Question 8.
Match the items given in Column I with those in Column II and select the correct option given below. [NEET (UG) 2018]

	Column I		Column II
i.	Glycosuria	a.	Accumulation of uric acid in joints
ii.	Gout	b.	Mass of crystalised salts within the kidney
iii.	Renal calculi	c.	Inflammation of glomeruli
iv.	Glomerular nephritis	d.	Presence of glucose in urine

(A) i-b, ii-c, iii-a, iv-d
(B) i-a, ii-b, iii-c, iv-d
(C) i-c, ii-b, iii-d, iv-a
(D) i-d, ii-a, iii-b, iv-c
Answer:
(D) i-d, ii-a, iii-b, iv-c

Question 9.
In the given diagram of Malpighian body, blood is filtered from part labelled ________

(A) L
(B) M
(C) N
(D) O
Hint: L – Afferent arteriole
M – Efferent arteriole
N – Glomerulus
O – Proximal convoluted tubule
Blood filtration occurs in glomerulus. Afferent arteriole is the blood vessel leading to glomerulus. Efferent arteriole carries blood away from the glomerulus. Proximal convoluted tubule is involved in reabsorption of useful substances from the filtrate.
Answer:
(C) N

Question 10.
Majority of kidney stones consist crystals of [MHT CET 2018]
(A) calcium oxalate, sodium bicarbonate
(B) calcium oxalate, calcium phosphate
(C) calcium phosphate, sodium chloride
(D) calcium carbonate, copper sulphate
Answer:
(B) calcium oxalate, calcium phosphate

Question 11.
Which of the following group of animals is guanotelic? [MHT CEE 2018]
(A) Labeo, turtle, camel
(B) Lizard, snake, scorpion
(C) Penguin, spider, scorpion
(D) Spider, scorpion, snake
Answer:
(C) Penguin, spider, scorpion

Question 12.
Which of the following statements is CORRECT? [NEET (UG) 2017]
(A) The ascending limb of loop of Henle is impermeable to water.
(B) The descending limb of loop of Henle is impermeable to water.
(C) The ascending limb of loop of Henle is permeable to water.
(D) The descending limb of loop of Henle is permeable to electrolytes.
Hint: Descending limb of loop of Henle is permeable to water but impermeable to electrolytes. While ascending limb of loop of Henle is impermeable to water and permeable to electrolytes.
Answer:
(A) The ascending limb of loop of Henle is impermeable to water.

Question 13.
A decrease in blood pressure/volume will not cause the release of [NEET (UG) 2017]
(A) Renin
(B) Atrial Natriuretic Factor
(C) Aldosterone
(D) ADH
Hint: Decrease in blood pressure or volume stimulates the release of renin, aldosterone and ADH. ANF is released when blood pressure increases or blood volume increases. Release of ANF causes vasodilation and also inhibit renin angiotensin mechanism that decreases blood pressure and blood volume.
Answer:
(B) Atrial Natriuretic Factor

Question 14.
Formation of urea takes place in the _________. [MHT CET 2017]
(A) Heart
(B) Kidney
(C) Liver
(D) Lung
Answer:
(C) Liver

Question 15.
The yellow colour of normal urine is due to [MHT CET 2017]
(A) Bilirubin
(B) Biliverdin
(C) Urochrome
(D) Uric acid
Answer:

Question 16.
Uremia is indicated when the blood urea level rises above _______ [MHT CET 2017]
(A) 0.05%
(B) 0.04%
(C) 0.03%
(D) 0.02 %
Answer:
(A) 0.05%

Balbharti Maharashtra State Board 11th Biology Important Questions 16 Skeleton and Movement Important Questions and Answers.

Maharashtra State Board 11th Biology Important Questions Chapter 16 Skeleton and Movement

Question 1.
Name the three types of muscles which bring about movements in humans.
Answer:

1. Smooth / non-striated / visceral / involuntary muscles
2. Cardiac muscles
3. Skeletal / straited / voluntary muscles.

Question 2.
Name the type of muscles which bring about running and speaking.
Answer:
Skeletal muscles (Voluntary muscles)

Question 3.
Name the muscles which do not contract as per our will.
Answer:
Involuntary muscles (smooth muscles and cardiac muscles)

Question 4.
Which type of muscles show rhythmic contractions?
Answer:
Cardiac muscles

Question 5.
Which type of muscle is present in the diaphragm of the respiratory system?
Answer:
Skeletal muscle

Question 6.
State the functions of:

1. Smooth muscles
2. Cardiac muscles
3. Striated muscles

Answer:

1. Smooth muscles: They bring about involuntary movements like peristalsis in the alimentary canal, constriction and dilation of blood vessels.
2. Cardiac muscles: They bring about contraction and relaxation of the heart.
3. Striated muscles: They control voluntary movements of limbs, head, trunk, eyes, etc.

Question 7.
What is locomotion?
Answer:
The change in locus of whole body of living organism from one place to another place is called locomotion.

Question 8.
State the four basic types of locomotory movements seen in animals.
Answer:
The four basic types locomotory movements seen in animals are:

1. Amoeboid movement: It is performed by pseudopodia, e.g. leucocytes.
2. Ciliary movement: It is performed by cilia, e.g. ciliated epithelium. In Paramoecium, cilia help in passage of food through cytopharynx.
3. Whirling movement: It is performed by flagella, e.g. sperms.
4. Muscular movement: It is performed by muscles, with the help of bones and joints.

Question 9.
All locomotions are movements but all movements are not locomotion. Justify
Answer:
Locomotion occurs when body changes its position, however all movements may not result in locomotion. Thus, all locomotions are movements but all movements are not locomotion.

Question 10.
Kriti was diagnosed with knee tendon injury. She asked the doctor whether she will be able to walk due to the injury? If not then state the reason.
Answer:
Knee tendon injury affects the ability to walk. Kriti may not be able to walk freely as the tendons attached to the bones help in the movement of the parts of skeleton.

Question 11.
Explain the types of straited muscles.
Answer:
On the basis of movements striated muscles are of three types:

1. Agonists: These are considered as the prime movers. They bring about the initial movement of a part.
   e.g. biceps
2. Antagonists: They bring about the action opposite to that of prime movers. e.g. Triceps.
3. Svnergists They assist the prime movers. e.g. Brachialis assist biceps.

Question 12.
Describe the antagonistic muscles in detail.
Answer:
Following are the important antagonistic muscles:

1. Flexor and extensor: Flexor muscle on contraction results into bending or flexion of joint. e.g. Biceps. Extensor muscle on contraction results in straightening or extension of a joint. e.g. Triceps.
2. Abductor and adductor: Abductor muscle moves a body part away from the body axis. e.g. Deltoid muscle of shoulder moves the arm away from the body. Adductor muscle moves a body part towards the body axis.
   e.g. L.atissirnus dorsi of shoulder moves the arm near the body.
3. Pronator and supinator: Pronator turns the palm downwards and supinator turns the palm upward.
4. Levator and depressor: Levator raises a body part and the depressors lower the body part.
5. Protractor and retractor: Protractor moves forward, whereas the retractor moves backward.
6. Sphincters: Circular muscles present in the inner walls of anus, stomach. etc., for closure and opening.

Question 13.
Describe the structure of myosin and actin filaments, with the help of neat and labelled diagram.
Answer:
i. Myosin filament:

1. Each myosin filament is a polymerized protein. Many meromyosins (monomeric proteins) constitute one thick filament.
2. Myosin molecule consists of two heavy chains (heavy meromyosin / HMM) coiled around each other forming a double helix. One end of each of these chains is projected outwardly is known as cross bridge. This end folds to form a globular protein mass called myosin head.
3. Two light chains are associated with each head forming 4 light chains/light meromyosin / LMM.
4. Myosin head has a special ATPase activity. It can split ATP to produce energy.
5. Myosin contributes 55% of muscle proteins.
6. In sarcomere, myosin tails are arranged to point towards the centre of the sarcomere and the heads point to the sides of the myofilament band.
   

ii. Actin filament: It is a complex type of contractile protein. It is made up of three components:

1. F actin: It forms the backbone of actin filament. F actin is made up of two helical strands. Each strand is composed of polymerized G actin molecules. One ADP molecule is attached to G actin molecule.
2. Tropomyosin: The actin filament contains two additional protein strands that are polymers of tropomyosin molecules. Each strand is loosely attached to an F actin. In the resting stage, tropomyosin physically covers the active myosin-binding site of the actin strand.
3. Troponin: It is a complex of three globular proteins, is attached approx. 2/3^rd distance along each tropomyosin molecule. It has affinity for actin, tropomyosin and calcium ions. The troponin complex is believed to attach the tropomyosin to the actin. The strong affinity of troponin for calcium ions is believed to initiate the contraction process.
   

Question 14.
A muscle can only pull and not push the bone. Why?
Answer:
The fundamental characteristic of the muscle is contraction. Therefore, muscle can only pull and not push the bone.

Question 15.
Explain the physiology of muscle contraction.
Answer:
When the muscles are relaxed, the active sites remain covered with tropomyosin and troponin complex. Due to this, myosin cannot interact with active site of actin and thus contraction cannot occur.

1. When an impulse (action potential) comes to muscle through motor end plate, it spreads throughout the sarcolemma of the myofibril.
2. The transverse tubules of sarcoplasmic reticulum release large number of Ca⁺⁺ ions into sarcoplasm. These calcium ions interact with the troponin molecules and the interaction inactivates troponin-tropomyosin complex. This causes change in the structure of tropomyosin.
3. As a result, tropomyosin gets detached from the active site of actin (F actin) filament, exposing the active site for actin.
4. The myosin head cleaves the ATP to derive energy and gets attached to the uncovered active site of actin. This results into the formation of acto-myosin complex.
5. The myosin heads are now tilted backwards and pull the attached actin filament inwardly. This results in contraction of the muscle fibres.

Question 16.
Why do we shiver during winter?
Answer:

1. Humans are homeotherms as they can regulate their body temperature with respect to the surrounding temperature. During winter, when temperature falls, the thermoreceptors detect the change in temperature and send signals to the brain.
2. Shivering reflex i.e. rapid contraction of muscles is triggered by the brain to generate heat and raise the body temperature.

Question 17.
Write a short note on role of calcium ions in contraction and relaxation of muscles.
Answer:
Calcium ions play a major role in contraction and relaxation of muscles.

1. Calcium ions are released from the sarcoplasm during muscle contraction and stored in sarcoplasmic reticulum during muscle relaxation.
2. When a skeletal muscle is excited and an action potential travels along the T tubule, the concentration of calcium ions increases.
3. These calcium ions bind to troponin which in turn undergoes a conformational change that causes tropomyosin to move away from the myosin-binding sites on actin. Once these binding sites are free, myosin heads bind to them to form cross-bridges and the muscle fiber contracts.
4. The decrease in calcium ion concentration in the sarcoplasmic reticulum causes tropomyosin to slide back and block the myosin binding sites on actin. This causes the muscle to relax.

[Note: Students can scan the adjacent Q.R code to get conceptual clarity with the aid of a relevant video.]

Question 18.
Muscle contraction and relaxation are active processes. Give reason.
Answer:
Muscle contraction and relaxation are active processes as during both the processes energy is utilized by hydrolysis of ATP into ADP and inorganic phosphate by the enzyme ATPase.

Question 19.
Describe the properties of muscles observed on electrical stimulation.
Answer:
Properties of muscles observed on electrical excitation:

1. Single muscle twitch: It is a muscle contraction initiated by a single brief-stimulation. It occurs in 3 stages: a latent period of no contraction, a contraction period and a relaxation period.
2. Summation: If the muscle is stimulated before the end of the twitch, it generates greater tension i.e., summation or addition of effect takes place. Repeated stimuli will produce increasing strength of contraction (stair case phenomenon).
3. Tetanus: If stimulation is very rapid and frequent the muscle does not have time to relax. It remains in a
   state of contraction called tetanus.
4. Rcfraètory period: Immediately aller one stimulus, the muscle fibre cannot respond to another stimulus. This resting or refractory period is about 0.02 seconds.
5. Threshold stimulus: For a muscle fibre to contract, a certain minimum strength or intensity of stimulus is required. This is called threshold stimulus.
6. All or none principie: A stimulus below threshold will not result in contraction. A threshold stimulus will result in contraction. This contraction leads to maximum force. Higher stimulus will not increase force of contraction i.e. a muscle libre contracts either ftilly or not at all. This is ‘all or none’ principle. All types of muscle and nerve fibres obey this law.
7. Oxygen debt: During strenuous exercise, the oxygen supply of muscle rapidly becomes insufficient to maintain oxidative phosphorylation of respiratory substrate. At this stage, muscles contract anaerobically and accumulate lactic acid produced by anaerobic glycolysis. Lactic acid produces less AlP and is toxic. It causes tiredness, pain and muscle cramps. During recovery, oxygen consumption of the muscle far exceeds than that in the resting state. This extra oxygen consumed during recovery is called oxygen debt of the muscle.

Note: The duration of refractory period varies with the muscle involved. Cardiac muscles have a longer refractory period of about 250 msec whereas skeletal muscles have a short refractory period of about I msec]

Question 20.
What is difference between endoskeleton and exoskeleton?
Answer:
The supportive structures present inside the body form the endoskeleton and when the supportive structures are present on the outer surface of the body they form exoskeleton.

Question 21.
Name the tissues that form the structural framework of the body.
Answer:
Cartilage and bone

Question 22.
What type of bones are present in our body?
Answer:
Long bones, short bones, flat bones, irregular bones and sesamoid bones.

Question 23.
How do bones help in various ways?
Answer:

1. Bones form the framework of our body and thus provide shape to the body.
2. They protect vital organs thus help in the smooth functioning of body.
3. The joints between the bones help in movement and locomotion.
4. They provide firm surface for attachment of muscles.
5. They are reservoirs of calcium and form important site for hemopoiesis.

Question 24.
Explain the three types of lever found in human body.
Answer:
The three types of lever are as follows:

1. Class I lever: The joint between the first vertebra and occipital condyle of skull is an example of Class I lever. The force is directed towards the joints (fulcrum); contraction of back muscle provides force while the part of head that is raised acts as resistance.
   
2. Class II lever: Human body raised on toes is an example of Class II lever. Toe acts as fulcrum, contracting calf muscles provide the force while raised body acts as resistance.
   
3. Class III lever: Flexion of forearm at elbow exhibit lever of class III. Elbow joint acts as fulcrum and radius, ulna provides resistance. Contracting bicep muscles provides force for the movement.
   

Question 25.
Give an account of bones of human skull.
Answer:
Skull is made up of 22 bones. It is located at the superior end of vertebral column. The bones of skull are
joined by fixed or immovable joints except for jaw.
Skull consists of cranium or brain box and facial bones.

i. Cranium: It is made up of four median bones and two paired bones.

1. Frontal bone: It is median bone (unpaired) forming forehead, roof of orbit (eye socket) and the most anterior part of cranium. It is connected to two parietals, sphenoid and ethmoid bone.
2. Parietal bones: These paired bones form the roof of cranium and greater portion of sides of the cranium.
3. Temporal bones: These paired bones are situated laterally just above the ear on either side. Each temporal bone gives out zygomatic process that joins zygomatic bone to form zygomatic arch. Just at the base of zygomatic process is mandibular fossa, a depression for mandibles (lower jaw bone) that forms the only movable joint of the skull. This bone harbors the ear canal that directs sound waves into the ear. The processes of temporal bones provide points for attachment for various muscles of neck and tongue.
4. Occipital bone: It is a single bone present at the back of the head. It forms the posterior part and most of the base of cranium. The inferior part of this bone shows foramen magnum, the opening through which medulla oblongata connects with spinal cord. On the either sides of foramen magnum are two prominent protuberances called occipital condyles. These fit into the corresponding depressions present in 1st vertebra.
5. Sphenoid bone: Median bone present at the base of the skull that articulates with all other cranial bones and holds them together. This butterfly shaped bone has a saddle shaped region called sella turcica. In this hypophyseal fossa, the pituitary gland is lodged.
6. Ethmoid bone: This median bone is spongy in appearance. It is located anterior to sphenoid and posterior to nasal bones. It contributes to formation of nasal septum and is major supporting structure of nasal cavity.

ii. Facial Bones: Fourteen facial bones give a characteristic shape to the face. The growth of face stops of the age of 16.
Following bones comprise the facial bones:

1. Nasals: These are paired bones that form the bridge of nose.
2. Maxillae: These form the upper jaw bones. They are paired bones that join with all facial bones except mandible. Upper row of teeth are lodged maxillae.
3. Palatines: These are paired bones forming the roof of buccal cavity or floor of the nasal cavity.
4. Zygomatic bones: They are commonly called as cheek bones.
5. Lacrimal bones: These are the smallest amongst the facial bones.
   These bones form the medial wall of each orbit. They have lacrimal fossa that houses lacrimal sacs. These sacs gather tears and send them to nasal cavity.
6. Inferior nasal conchae: They form the part of lateral wall of nasal cavity. They help to swirl and filter air before it passes to lungs.
7. Vomer: The median, roughly triangular bone that forms the inferior portion of nasal septum.
8. Mandible: This median bone forms the lower jaw. It is the largest and strongest facial bone. It is the only movable bone of skull. It has curved horizontal body and two perpendicular branches i.e. rami. These help in attachment of muscles. It has lower row of teeth lodged in it.

Question 26.
Give an account of hyoid bone.
Answer:

1. It is a ‘U’ shaped bone that does not articulate with any other bone.
2. It is suspended from temporal bone by ligaments and muscles.
3. It is located between mandible and larynx.
4. It has horizontal body and paired projections called horns.
5. It provides site for attachment of some tongue muscles and muscles of neck and pharynx.
   

Question 27.
Sketch and label the anterior and ‘entraI view of skull.
Answer:

Question 28.
Mention the sutures in skull along with their location.
Answer:
Skull has many sutures (type of immovable joints) present, out of which four prominent ones are:

1. Coronal suture; Joins frontal bone with parietals.
2. Sagittal suture: Joins two parietal bones.
3. Lambdiodal suture: Joins two parietal bones with occipital bone.
4. Lateral/squamous sutures: Joins parietal and temporal bones on lateral side.

Question 29.
What are ear ossicles?
Answer:
The three tiny bones present in each middle ear namely malleus, incus and stapes, together are called ‘ear ossicles’

Question 30.
Draw a neat and labelled diagram of ear ossicles.
Answer:

Question 31.
Write a note on human vertebral column. Sketch and label the structure of the vertebral column.
Answer:

1. Human vertebral column or backbone is a part of axial skeleton.
2. It is made up of a chain of irregular bones called vertebrae.
   
3. Humans have 33 vertebrae in early years of growth, whereas adults have 26 vertebrae.
4. In adults, five sacral vertebrae lìjse to tòrm one sacrum and four coccygeal vertebrae fuse to form single coccyx.

Question 32.
Explain the cervical vertebrae in detail.
Answer:

1. Atlas vertebrae:
   
2. It is the 1^st cervical vertebra.
3. It is a ring like bone and consists of anterior and posterior arches.
4. It does not have centrum and spinous process.
5. The transverse processes and transverse foramina of atlas are large.
6. The vertebral foramen is large and divided into two parts by transverse ligament.
7. Spinal cord passes through anterior compartment.
8. Anterior zygopophyses are replaced by facets for attachment with occipital condyle of skull that forms ‘Yes joint’.

ii. Axis vertebrae:

1. It is the 2^nd cervical vertebrae.
2. The centrum of this vertebra gives out tooth-like odontoid process.
   
3. Odontoid process fits into the anterior portion of vertebral foramen of atlas vertebra thereby forming pivot joint, also known as ‘No joint’.

iii. Typical cervical vertebrae:

1. Vertebrae number 3 to 6 are called as typical cervical vertebrae.
2. They show short centrum and bifid spinous process.
3. The transverse processes of these vertebrae are reduced; each having large vertebrarterial canal at its base for the passage of vertebral artery.

iv. 7^th cervical vertebra (Vertebra prominens): It is the largest cervical vertebra where the neural spine is straight.

Question 33.
Write a note on thoracic vertebrae. Sketch and label thoracic vertebrae.
Answer:

1. There are 12 thoracic vertebrae found in the chest region.
2. The centrurn of thoracic vertebrae is heart shaped and all the processes are well developed.
3. Except for 11^th and 12^th vertebrae; transverse process of other thoracic vertebrae show facets for attachment with ribs.
   

Question 34.
Elaborate on lumbar vertebrae with help of a neat and labelled diagram.
Answer:

1. There are 5 lumbar vertebrae.
2. They are well developed vertebrae and exhibit all the characters of a typical vertebrae.
3. The centrum of the lumbar vertebrae is kidney shaped.

Question 35.
Give an account on:
i. Sacrum
ii. Coccyx
Answer:
i. Sacrum:

1. It is a triangular bone formed by the fusion of five sacral vertebrae.
2. It is located in pelvic cavity between two hip bones.
3. The anterior end of sacrum is broad and posterior end is narrow.
4. It consists of vertebral foramina formed by the fusion of vertebrae.
5. The reduced neural spines can be observed projecting from dorsal aspect of sacrum.
6. Function: It gives strength to pelvic girdle,

ii. Coccyx:

1. It is a triangular bone which is formed by fusion of four coccygeal vertebrae.
2. It is reduced and does not show vertebral foramina and spinous processes.
3. The transverse processes of coccygeal vertebrae are reduced.

Question 36.
Identify the given vertebrae and label it.

Answer:

Question 37.
Describe in brief the structure of thoracic cage.
Answer:
Thoracic cage consists of 12 pairs of ribs, breast bone or sternum.

i. Ribs:

1. A rib is a ‘C’ shaped bone. It is attached to respective thoracic vertebrae on dorsal side.
2. Twelve pairs of ribs are attached to twelve thoracic vertebrae. For attachment to the vertebrae the posterior ends of ribs have two protuberances namely the head and tubercle.
3. The head of rib attaches to facet formed by demifacets of adjacent thoracic vertebrae at the base of transverse processes.
   
4. The tip of transverse processes of these vertebrae also have facets for attachment of ribs where tubercles of ribs are attached.
5. Ribs provide space for attachment of intercostal muscles.
6. On ventral side, the ribs may or may not attach the sternum. Depending on their attachment, the ribs are classified into three types:
   1. True ribs: First seven pairs of ribs are attached directly to the sternum by means of their costal cartilages.
   2. False ribs: Costal cartilages of rib numbers 8, 9 and 10 are attached to rib number 7 on either side and not directly to the sternum. Hence, these are called false ribs.
   3. Floating ribs: Last two pairs of ribs have no ventral connection. Hence, they are called floating ribs.

ii. Sternum:

1. It is a flat, narrow bone, around 15 cms in length.
   
2. It is placed medially in anterior thoracic ] jugular notch wall (chest region).
3. It consists of three distinct parts – manubrium, body and xiphoid processes.
4. Manubrium shows two notches on anterio-lateral side for attachment with clavicle of each side. It also shows two notches on each of the lateral side for attachment of first two pairs of ribs.
5. Body of sternum is a flat bone that shows five notches on lateral aspect which are meant for direct or indirect attachment of ribs.
6. Xiphoid process is lowermost part of sternum which is initially cartilaginous and gets ossified in adults. It provides space for the attachment of diaphragm and abdominal muscles.
7. Ribs are attached to sternum by means of cartilaginous extensions called costal cartilages.

Question 38.
What is intercostal space?
Answer:
The space between the ribs is called as intercostal space.

Question 39.
Describe the bones of pectoral girdle.
Answer:

Pectoral girdle is called as shoulder girdle. It attaches forelimb skeleton with axial skeleton. There are two pectoral girdles, each consists of a shoulder blade or scapula and collar bone or clavicle.

i. Clavicle:

1. It is a ‘S’ shaped slender bone.
2. One end of clavicle is attached to acromion process of scapula. The other rounded end called sternal end attaches to manubrium of sternum.
3. This connects upper arm skeleton to axial skeleton.

ii. Scapula:

1. It is a large, flat, triangular bone that occupies posterior chest wall extending from 2nd to 7th ribs.
2. It is attached to axial skeleton by muscles and tendons.
3. Scapula bears a concave socket called glenoid cavity at its lateral angle.
4. Head of humerus (the upper arm bone) fits into the glenoid cavity.
5. A beak like coracoid process projects from lateral angle of scapula and acromion process arise from scapula. They can be easily felt as high point of shoulder. Both the processes are meant for attachment of muscles.

Question 40.
Describe the bones of forelimb.
Answer:
Forelimb consists of humerus, radius and ulna (together forming forearm bones), carpals (bones of wrist), metacarpals (bones of palm) and phalanges (bones of digits). It consists of 30 bones.

i. Humerus:

1. This is the bone of upper arm.
2. It has a hemispherical head at its proximal end. On either side of head of humerus are present a pair of projections termed greater and lesser tubercles.
   
3. Bicipital groove is a deep groove present between the tubercles where a tendon of biceps muscle is attached.
4. The shaft of humerus shows deltoid tuberosity. Distal end of humerus shows pulley like part called trochlea that articulates with ulna.

ii. Radius and Ulna:

1. Radius is located laterally on thumb side of the forearm.
2. The proximal end of radius has disc like head that articulates with humerus bone.
3. The shaft of radius widens distally to form styloid process.
4. Ulna is located medially on little finger side of forearm.
5. At the proximal end of ulna there is a prominent process called Olecranon process that forms elbow joint with humerus bone. On the lateral side, near the upper end of ulna is present the radial notch into which the side of head of radius is fixed.
   
   f. Radius and ulna articulate with each other at upper and lower extremities by superior and inferior radio-ulnar joints. In between the shaft of two bones, interosseous membrane is present.

iii. Carpals: These are bones of wrist, arranged in two rows of four each.

iv. Metacarpals: Five elongated metacarpals form the bones of palm. Their proximal ends join with carpals and distal ends form knuckles.

v. Phalanges: Phalanges form the bones of fingers and thumb. There are 14 phalanges in each hand (Four fingers have three phalanges each and thumb has two).

Question 41.
Explain briefly the pelvic girdle with a neat and labelled diagram.
Answer:

1. Pelvic girdle also known as hip girdle connects hind limb skeleton with axial skeleton.
2. It is made up of two hip bones called coxal bones. These coxal bones unite posteriorly with sacrum.
3. Coxal bone is a large irregularly shaped bone is made up of three parts – ilium, ischium and pubis.
4. At the point of fusion of ilium, ischium and pubis, a cavity called acetabulum is present that forms ball and socket joint with the thigh bone.
   
5. The two pubis bones are joined medially by cartilaginous joint called pubic symphysis. Pubis and ischium together form a ring of bone that encloses a space called obturator foramen.

Question 42.
Describe the bones of lower limb.
Answer:
The bones of lower limb are femur, patella, tibia and fibula, tarsals, metatarsals and phalanges.

i. Femur: The thigh bone is the longest bone in the body. The head is joined to shaft at an angle by a short neck. It forms ball and socket joint with acetabulum cavity of coxal bone. The lower one third region of shaft is triangular flattened area called popliteal surface. Distal end has two condyles that articulate with tibia and fibula.

ii. Patella: It is also called as knee cap. ft is a sesamoid bone (bone embedded in tendon). It is a flat rounded bone with a pointed lower end.

iii. Tibia and fibula: These are the two long bones of shank or lower leg. The two bones are connected to each other at the extremities. In between the two bones interosseous membrane is present.

1. Tibia: It is much thicker and stronger than fibula. Its broad and expanded upper end articulates with femur and the lower end articulates with talus (tarsal bone).
2. Fibula: It is a long slender bone on lateral side of tibia.
   

iv. Tarsals: These are the bones of ankle. Seven tarsals are arranged in three rows, two proximal, one intermediate and four distal.

v. Metatarsals: Five metatarsal bones support the foot. Proximally they attach with distal row of tarsals and distally the metatarsals articulate with phalanges.

vi. Phalanges: These are the bones of the toes. Except the big toe which has two phalanges, the other four toes have three phalanges each.

Question 43.
What is arthrology?
Answer:
The study of joints is called arthrology.

Question 44.
What makes synovial joint freely movable?
Answer:
Synovial joint is characterised by synovial cavity between the articulating bones which allows free movement at the joint. This makes the joint freely movable.

Question 45.
Complete the given table.

Answer:

Question 46.
State and explain the disorders related to muscles.
Answer:
i. Muscular dystrophy:

1. It is a gradual wasting disease affecting various groups of muscles.
2. It is a genetic disorder.
3. Usually the voluntary skeletal muscles are weakened whereas internal muscles such as diaphragm are not affected in the patient suffering from this disorder.
4. The Duchenne type of muscular dystrophy usually occurs in boys, affecting their lower limbs.
5. Limb girdle muscular dystrophy affects the muscles of shoulders or hips and it usually starts in adults between 20 – 30 years.
6. There is no cure for this disease.

ii. Myasthenia gravis:

1. It is a weakness of skeletal muscles.
2. It is caused by an abnormality at the neuromuscular junction that partially blocks muscle contraction.
3. It is an autoimmune disorder caused by excessive production of certain antibodies in the blood stream. These antibodies bind to acetylcholine receptors of neuromuscular junction. Thus, the transmission of nerve impulses to the muscle fibres is blocked. This causes progressive and extensive muscle weakness.
4. It may affect the eye and eyelid movements, facial expression and swallowing.
5. The degree of muscle weakness varies from local to general.
6. Symptoms: Ptosis (drooping or falling of upper eye lid), diplopia or double vision, difficulty in swallowing, chewing and speech.

Question 47.
Give an account on disorders related to bones.
Answer:

1. Arthritis: It is an inflammation of joints. It is a painful disorder of bones, ligaments, tendons, etc. In this disorder, joints become swollen, stiff and painful. It can lead to disability.
2. Arthritis is of three types:
   1. Osteoarthritis: In this disorder, the joint cartilage is degenerated. It is caused by various factors like aging, obesity, muscle weakness, etc. This is the most common type of arthritis that affects hands, knees and spine.
   2. Gouty arthritis (Gout): In this disorder, joint pain occurs due to the deposition of uric acid in joints. If uric acid is produced in excess or is not excreted, it accumulates in joints as sodium urate. The accumulated sodium urate degenerates the cartilage causing inflammation and pain. It generally affects the joints of feet.
   3. Rheumotoid arthritis: It is an autoimmune disorder where body’s immune system attacks its own tissues. In rheumatoid arthritis, synovial membrane swells up and starts secreting extra synovial fluid. This fluid exerts pressure on joint and makes it painful. Membrane may develop abnormal granulation tissue called pannus. Pannus may erode cartilage. Fibrous tissue gets ossified and may lead to stiffness in joints.
3. Osteoporosis:
   1. In this disorder, bones become porous and hence brittle. It is primarily age related disease and is more common in women than men.
   2. As age advances, bone resorption outpaces bone formation. Hence, the bones lose mass and become brittle. More calcium is lost in urine, sweat, etc., than it is gained through diet. Thus, prevention of disease is better than treatment by consuming adequate amount of calcium and exercise at young age.
   3. Osteoporosis may be caused due to decreasing estrogen secretion after menopause, deficiency of vitamin D, low calcium diet, decreased secretion of sex hormones and thyrocalcitonin.

Question 48.
Name the following.

Question 1.
The striated muscles that are known as prime movers
Answer:
Agonists

Question 2.
The antagonistic muscles that lower the body part
Answer:
Depressor

Question 3.
The contractile proteins of sarcomere
Answer:
Actin and myosin

Question 4.
Sliding filament theory is also known as
Answer:
Walk along theory or Rachet theory

Question 5.
The smallest facial bone
Answer:
Lacrimal bones

Question 6.
Number of bones in thoracic cage
Answer:
25

Question 7.
The first cervical vertebrae
Answer:
Atlas

Question 8.
The three bones of pelvic girdle
Answer:
Ilium, ischium and pubis

Question 9.
The bone which is known as the knee cap
Answer:
Patella

Question 10.
Age related disorder more common in woman than man.
Answer:
Osteoporosis

Question 49.
Fill in the blanks.

Question 1.
The actin filament contains two additional proteins strands that are polymers of ___ molecules.
Answer:
tropomyosin

Question 2.
___ of sarcoplasmic reticulum release large number of Ca⁺⁺ into sarcoplasm.
Answer:
Transverse (T) tubules

Question 3.
The joint between the first vertebra and occipital condyle of skull is an example of ____ class of lever.
Answer:
Class I

Question 4.
Endoskeleton of an adult human consists of ___ bones.
Answer:
206

Question 5.
___ are the bones that connect limbs to the axial skeleton.
Answer:
Girdles

Question 6.
___ bones form the roof of cranium.
Answer:
Parietal

Question 7.
Zveomatic bone is commonly known as ___ bone.
Answer:
Cheek

Question 8.
The largest and strongest facial bone is ___
Answer:
Mandible

Question 9.
There are ___ types of vertebrae.
Answer:
5

Question 10.
___ is also known as shoulder girdle.
Answer:
Pectoral girdle

Question 11.
___ are the bones of wrist.
Answer:
Carpals

Question 12.
___ is known as immovable or fixed joint.
Answer:
Synarthroses

Question 13.
Tibia and fibula are two long bones of ___.
Answer:
Shank or lower leg

Question 14.
___ is caused due to deposition of uric acid in joints.
Answer:
Gouty arthritis

Question 50.
State whether the following statements are True or False:

Question 1.
Saggital suture joins frontal bone with parietal bone.
Answer:
False. Saggital suture joins two parietal bones.

Question 2.
In human beings, there are 10 pairs of ribs.
Answer:
False. In human beings, there are 12 pairs of ribs.

Question 3.
Hyoid bone does not articulate with any other bone.
Answer:
True

Question 4.
Pivot joint is present between Atlas and Axis vertebrae.
Answer:
True

Question 5.
The two pubis bones are joined by cartilaginous joint called pubic symphysis.
Answer:
True

Question 6.
Rheumatoid arthritis is an autoimmune disorder.
Answer:
True

Question 50.
Identify the INCORRECTLY labelled part of pectoral girdle.

Answer:
Glenoid cavity is incorrectly labelled as obturator foramen.

Multiple Choice Questions

Question 1.
Locomotion in sperms takes place with the help of
(A) flagella
(B) cilia
(C) pseudopodia
(D) muscles
Answer:
(A) flagella

Question 2.
Levator muscles result into the action of
(A) lowering a body part
(B) tensing a body part
(C) relaxing a body part
(D) raising a body part
Answer:
(D) raising a body part

Question 3.
Which of these is not a skull bone?
(A) Frontal
(B) Scapula
(C) Occipital
(D) Temporal
Answer:
(B) Scapula

Question 4.
Immovable joint is in between the bones of
(A) frontal and parietal
(B) metacarpal and phalangeal
(C) femur and tibia
(D) radius and ulna
Answer:
(A) frontal and parietal

Question 5.
Total number of vertebrae in human beings is
(A) 22
(B) 33
(C) 24
(D) 12
Answer:
(B) 33

Question 6.
Which of the following is NOT a part of appendicular skeleton?
(A) Girdles
(B) Forelimb
(C) Hindlimb
(D) Vertebral column
Answer:
(D) Vertebral column

Question 7.
___ connects the upper arm to the axial skeleton.
(A) Clavicle
(B) Patella
(C) Tibia
(D) Femur
Answer:
(A) Clavicle

Question 8.
__ is a part of hind limb.
(A) Radius
(B) Ulna
(C) Humers
(D) Fibula
Answer:
(D) Fibula

Question 9.
Which of the following are toe bones?
(A) Tarsals
(B) Metatarsals
(C) Carpals
(D) Phalanges
Answer:
(D) Phalanges

Question 10.
Sutures on the skull are ___ joints.
(A) freely movable
(B) slightly movable
(C) fixed
(D) synovial
Answer:
(C) fixed

Question 11.
___ is an example of syndesmoses.
(A) Distal tibiofibular joint
(B) Rib-sternum junction
(C) Tooth and jaw bones
(D) Intervertebral disc
Answer:
(A) Distal tibiofibular joint

Question 12.
Elbow joint is
(A) ball and socket joint
(B) hinge joint
(C) suture joint
(D) gliding joint
Answer:
(B) hinge joint

Question 13.
Complete the analogy.
Hinge joint: Monoaxial movement:: ___ Biaxial movement
(A) Ball and socket joint
(B) Gliding joint
(C) Condyloid joint
(D) Both (A) and (B)
Answer:
(C) Condyloid joint

Question 14.
An autoimmune disorder in which an antibody reduces the efficiency of transmission between the motor neuron is called
(A) Myasthenia gravis
(B) Tetany
(C) Osteoarthritis
(D) Osteoporosis
Answer:
(A) Myasthenia gravis

Balbharti Maharashtra State Board 12th Biology Important Questions Chapter 2 Reproduction in Lower and Higher Animals Important Questions and Answers.

Maharashtra State Board 12th Biology Important Questions Chapter 2 Reproduction in Lower and Higher Animals

Multiple-choice questions

Question 1.
Gemmule formation takes place in ……………….
(a) Hydra
(b) Spongilla
(c) Planaria
(d) Human being
Answer:
(b) Spongilla

Question 2.
Which part of ovary in mammals acts as an endocrine gland after ovulation?
(a) stroma
(b) germinal epithelium
(c) vitelline membrane
(d) graafian follicle
Answer:
(d) graafian follicle

Question 3.
Cessation of menstrual cycle in female is called ……………….
(a) lactation
(b) ovulation
(c) menarche
(d) menopause
Answer:
(d) menopause

Question 4.
Capacitation of sperms occurs in ……………….
(a) vas deferens
(b) vas efferens
(c) vagina
(d) ejaculatory duct
Answer:
(c) vagina

Question 5.
How many sperms are formed from a secondary spermatocyte ?
(a) 4
(b) 8
(c) 2
(d) 1
Answer:
(c) 2

Question 6.
The middle piece of the sperm contains ……………….
(a) proximal centriole
(b) nucleus
(c) mitochondria
(d) distal centriole
Answer:
(c) mitochondria

Question 7.
About which day in a normal human menstrual cycle does rapid secretion of LH (popularly called LH surge) normally occurs ?
(a) 14th day
(b) 20th day
(c) 5th day
(d) 11th day
Answer:
(a) 14th day

Question 8.
Morphogenetic movements occur during ……………….
(a) blastulation
(b) gastrulation
(c) fertilization
(d) cleavage
Answer:
(b) gastrulation

Question 9.
The technique used to block the passage of sperm in male is ……………….
(a) tubectomy
(b) vasectomy
(c) coitus interruptus
(d) rhythm method
Answer:
(b) vasectomy

Question 10.
Planaria reproduces asexually through ……………….
(a) budding
(b) gemmule formation
(c) regeneration
(d) binary fission
Answer:
(c) regeneration

Question 11.
The role of Leydig cells is ……………….
(a) nourishment of sperms
(b) to give motility to sperms
(c) synthesis of testosterone
(d) to undergo spermatogenesis
Answer:
(c) synthesis of testosterone

Question 12.
Chancre are the primary lesions caused by ……………….
(a) Neisseria gonorrhoeae
(b) Treponema pallidum
(c) Plasmodium vivax
(d) Salmonella typhi
Answer:
(b) Treponema pallidum

Question 13.
Smooth muscles lining the wall of scrotum are called ……………….
(a) detrusor muscles
(b) dartos muscles
(c) gluteal muscles
(d) latissimus dorsi muscles
Answer:
(b) dartos muscles

Question 14.
The trophoblast cells in contact with embryonal knob are called ……………….
(a) inner mass cells
(b) blastomere
(c) amniogenic cells
(d) cells of Rauber
Answer:
(d) cells of Rauber

Question 15.
The external layer of collagenous connective tissue of human testis is ……………….
(a) tunica vasculosa
(b) tunica vaginalis
(c) tunica granulosa
(d) tunica albuginea
Answer:
(d) tunica albuginea

Question 16.
Which of the following is mesodermal in origin ?
(a) Retina
(b) Enamel of teeth
(c) Heart
(d) Liver
Answer:
(c) Heart

Question 17.
Pregnancy in second trimester is maintained by ……………….
(a) LH (luteinizing hormone)
(b) progesterone
(c) estrogen
(d) hCG (human Chorionic Gonadotropin)
Answer:
(b) progesterone

Question 18.
In human foetus, the heart begins to beat at developmental age of ……………….
(a) 4th week
(b) 3rd week
(c) 6th week
(d) 8th week
Answer:
(c) 6th week

Question 19.
……………… contribute about 60% of the total volume of the semen.
(a) Prostate gland
(b) Cowper’s glands
(c) Seminal vesicles
(d) Bartholin’s glands
Answer:
(c) Seminal vesicles

Question 20.
Which of the following is hormone releasing IUD?
(a) Lippes loop
(b) Cu 7
(c) LNG 20
(d) Multiload 375
Answer:
(c) LNG 20

Question 21.
Which of the following is incorrect regarding vasectomy?
(a) Vasa deferentia is cut and tied
(b) Irreversible sterility
(c) No sperm occurs in seminal fluid
(d) No sperm occurs in epididymis
Answer:
(d) No sperm occurs in epididymis

Question 22.
The test-tube baby programme employs which one of the following techniques?
(a) Gamete intra fallopian transfer (GIFT)
(b) Zygote intra fallopian transfer (ZIFT)
(c) Intra cytoplasmic sperm injection (ICSI)
(d) Intra uterine insemination (IUI)
Answer:
(b) Zygote intra fallopian transfer (ZIFT)

Question 23.
Medical Termination of Pregnancy (MTP) is considered safe up to how many weeks of pregnancy?
(a) 8 weeks
(b) 12 weeks
(c) 24 weeks
(d) 6 weeks
Answer:
(b) 12 weeks

Question 24.
‘Saheli? an oral contraceptive pill is to be taken ……………….
(a) daily
(b) weekly
(c) quarterly
(d) monthly
Answer:
(b) weekly

Question 25.
The role of copper releasing IUDs is to ……………….
(a) inhibit ovulation
(b) prevent fertilization
(c) inhibit implantation of blastocyst
(d) inhibit gametogenesis
Answer:
(b) prevent fertilization

Question 26.
The phenomenon of nuclear fusion of sperm and egg is known as ……………….
(a) karyogamy
(b) parthenogenesis
(c) vitellogenesis
(d) oogenesis
Answer:
(a) karyogamy

Question 27.
Acrosome of spermatozoa is formed from ……………….
(a) lysosomes
(b) Golgi bodies
(c) ribosomes
(d) mitochondria
Answer:
(b) Golgi bodies

Question 28.
Which of the following undergoes spermiogenesis ?
(a) Spermatids
(b) Spermatogonia
(c) Primary spermatocytes
(d) Secondary spermatocytes
Answer:
(a) Spermatids

Question 29.
In mammals, the estrogens are secreted by the graafian follicle from its ……………….
(a) theca externa
(b) theca interna
(c) membrane granulosa
(d) corona radiata
Answer:
(b) theca interna

Question 30.
Which hormone is essential for maintenance of the endometrium of uterus?
(a) FSH
(b) LH
(c) Progesterone
(d) Estrogen
Answer:
(c) Progesterone

Question 31.
Which of the following cells during gametogenesis is normally diploid?
(a) Spermatid
(b) Spermatogonia
(c) Second polar body
(d) Secondary oocyte
Answer:
(b) Spermatogonia

Question 32.
Fertilization takes place at ……………….
(a) cervix
(b) ampulla
(c) isthmus
(d) vagina
Answer:
(b) ampulla

Question 33.
In mammals, failure of testes to descend into scrotum is known as ……………….
(a) paedogenesis
(b) castration
(c) cryptorchidism
(d) impotency
Answer:
(c) cryptorchidism

Question 34.
Polar body is produced during the formation of ……………….
(a) sperm
(b) secondary oocyte
(c) oogonium
(d) spermatocytes
Answer:
(b) secondary oocyte

Question 35.
Menstrual flow occurs due to lack of ……………….
(a) vasopressin
(b) progesterone
(c) FSH
(d) oxytocin
Answer:
(b) progesterone

Question 36.
Approximately how many eggs are produced by a normal healthy human female up to the age of 25 years if the age of menarche is 12 years?
(a) 169
(b) 416
(c) 240
(d) 100
Answer:
(a) 169

Question 37.
In humans, at the end of the first meiotic division, the male germ cells differentiate into the ……………….
(a) spermatids
(b) spermatozoa
(c) primary spermatocytes
(d) secondary spermatocytes
Answer:
(d) Secondary spermotocytes

Question 38.
The part that carries sperms from testis to epididymis is ……………….
(a) rete testis
(b) vasa efferentia
(c) vasa differentia
(d) ejaculatory ducts
Answer:
(c) vasa differentia

Question 39.
Which period of menstrual cycle is called risky period of conception?
(a) 3rd to 7th day
(b) 7th to 13th day
(c) 10th to 17th day
(d) 15th to 25th day
Answer:
(c) 10th to 17th day

Question 40.
Which hormone confirms pregnancy?
(a) Progesterone
(b) Estrogen
(c) hCG
(d) LH
Ans
(c) hCG

Match the columns

Question 1.

Column I [Organs]	Column II [Functions]
(1) Epididymis	(a) Transport of sperms
(2) Sertoli cells	(b) Copulatory organ
(3) Vas deferens	(c) Nourishment to developing sperms
(4) Penis	(d) Maturation of sperms

Answer:

Column I [Organs]	Column II [Functions]
(1) Epididymis	(d) Maturation of sperms
(2) Sertoli cells	(c) Nourishment to developing sperms
(3) Vas deferens	(a) Transport of sperms
(4) Penis	(b) Copulatory organ

Question 2.

Column I [Organ/cells]	Column II [Hormones]
(1) Corpus luteum	(a) hCG
(2) Interstitial cells / Leydig’s cells	(b) Estrogen
(3) Placenta	(c) Progesterone
(4) Graafian follicle	(d) Testosterone

Answer:

Column I [Organ/cells]	Column II [Hormones]
(1) Corpus luteum	(c) Progesterone
(2) Interstitial cells / Leydig’s cells	(d) Testosterone
(3) Placenta	(a) hCG
(4) Graafian follicle	(b) Estrogen

Question 3.

Column I	Column II
(1) Graafian follicle	(a) Site of implantation
(2) Uterus	(b) Birth canal
(3) Fallopian tube	(c) Site of fertilization
(4) Vagina	(d) Release of secondary oocyte

Answer:

Column I	Column II
(1) Graafian follicle	(d) Release of secondary oocyte
(2) Uterus	(a) Site of implantation
(3) Fallopian tube	(c) Site of fertilization
(4) Vagina	(b) Birth canal

Question 4.

Column I [Phases]	Column II [Hormonal changes]
(1) Menstrual phase	(a) Rapid secretion of LH
(2) Proliferative phase	(b) Increased level of FSH and estrogen
(3) Ovulatory phase	(c) Increased level of progesterone
(4) Secretory phase	(d) Decrease in progesterone and estrogen

Answer:

Column I [Phases]	Column II [Hormonal changes]
(1) Menstrual phase	(d) Decrease in progesterone and estrogen
(2) Proliferative phase	(b) Increased level of FSH and estrogen
(3) Ovulatory phase	(a) Rapid secretion of LH
(4) Secretory phase	(c) Increased level of progesterone

Question 5.

Column I	Column II
(1) Acrosome	(a) Completion of IInd meiotic division of secondary oocyte
(2) Penetration of sperm into ovum	(b) Dissolution of zona pellucida
(3) Formation of fertilization membrane	(c) Secretion of Hyaluronidase
(4) Acrosin / Zona lysine	(d) Prevention of polyspermy

Answer:

Column I	Column II
(1) Acrosome	(c) Secretion of Hyaluronidase
(2) Penetration of sperm into ovum	(a) Completion of IInd meiotic division of secondary oocyte
(3) Formation of fertilization membrane	(d) Prevention of polyspermy
(4) Acrosin / Zona lysine	(b) Dissolution of zona pellucida

Question 6.

Column I	Column II
(1) Parturition	(a) Attachment of embryo to endometrium
(2) Gestation	(b) Release of egg from Graafian follicle
(3) Ovulation	(c) Delivery of baby from uterus
(4) Implantation	(d) Duration between pregnancy and birth

Answer:

Column I	Column II
(1) Parturition	(c) Delivery of baby from uterus
(2) Gestation	(d) Duration between pregnancy and birth
(3) Ovulation	(b) Release of egg from Graafian follicle
(4) Implantation	(a) Attachment of embryo to endometrium

Question 7.

Column I [Contraceptive method]	Column II [Mode of action]
(1) Pill	(a) Prevents sperms reaching cervix
(2) Condom	(b) Prevents implantation
(3) Vasectomy	(c) Prevents ovulation
(4) Copper T	(d) Semen contains no sperms

Answer:

Column I [Contraceptive method]	Column II [Mode of action]
(1) Pill	(c) Prevents ovulation
(2) Condom	(a) Prevents sperms reaching cervix
(3) Vasectomy	(d) Semen contains no sperms
(4) Copper T	(b) Prevents implantation

Question 8.

Column I	Column II
(1) Mechanical means	(a) Saheli
(2) Physiological device	(b) Jellies
(3) Chemical device	(c) Vasectomy
(4) Permanent method	(d) Diaphragm

Answer:

Column I	Column II
(1) Mechanical means	(d) Diaphragm
(2) Physiological device	(a) Saheli
(3) Chemical device	(b) Jellies
(4) Permanent method	(c) Vasectomy

Classify the following to form Column B as per the category given in Column A.

Question 1.
Classify the following contraceptives given below as per Column ‘A’ and complete Column ‘B’. Select from the given options:
(i) Foams
(ii) Lippe’s loop
(iii) Cervical caps
(iv) Multiload 375
(v) Diaphragms
(vi) Jellie

Column A	Column B
(1) Mechanical means	————–, ————
(2) Chemical means	————-, ————-
(3) Intra-uterine device	————-, ————

Answer:

Column A	Column B
(1) Mechanical means	Cervical caps, Diaphragms
(2) Chemical means	Foams, Jellies
(3) Intra-uterine device	Lippe’s loop, Multiload 375

Question 2.
Classify the following components of semen given below as per Column ‘A’ and complete the Column ‘B’. Select from the given options
(i) Acid phosphatase
(ii) Mucous like fluid
(iii) Prostaglandins
(iv) Citric acid
(v) Fructose
(vi) Fibrinogen

Column A	Column B
(1) Seminal fluid	————–, ————
(2) Prostatic fluid	————-, ————-
(3) Fluid from Cowper’s gland	————-, ————

Answer:

Column A	Column B
(1) Seminal fluid	Prostaglandins, Fructose, Fibrinogen
(2) Prostatic fluid	Acid phosphatase, Citric acid
(3) Fluid from Cowper’s gland	Mucous like fluid

Very short answer questions

Question 1.
How many sperms are present in single ejaculation?
Answer:
A single ejaculation contains about 400 millions of sperms.

Question 2.
What is gemmule? How is gemmule formed ?
Answer:
Gemmule is an internal bud formed by aggregation of archeocytes in sponges to overcome unfavourable season.

Question 3.
What is cryptorchidism?
Answer:
Failure of testis to descend into scrotum leading to sterility is called cryptorchidism.

Question 4.
What is the beginning of the menstrual cycle and cessation of menstrual cycle respectively called?
Answer:
The beginning of the menstrual cycle is called menarche while cessation of menstrual cycle is called menopause.

Question 5.
Which men have an increased risk of prostate cancer?
Answer:
Men who are over 50 years of age and have a daily high consumption of fat have an increased risk of prostate cancer.

Question 6.
What is capacitation with reference to sperm?
Answer:
Changes in a mammalian sperm which prepare it for fertilization of ovum is called capacitation.

Question 7.
Give any two examples each of seasonal breeders and continuous breeders among sexually reproducing animals.
Answer:
Example of seasonal breeders : Goat, Sheep and Donkey.
Example of continuous breeders : Humans, apes.

Question 8.
What does IUCD indicate?
Answer:
IUCD means Intra Uterine Contraceptive Device.

Question 9.
What is full form of IVF?
Answer:
IVF means In Vitro Fertilization.

Question 10.
From which germinal layers the nervous system is derived?
Answer:
The nervous system is derived from ectoderm.

Question 11.
A mother of a one-year-old child wanted to space her second child. Her doctor suggested ‘Copper-T’. Explain its contraceptive action.
Answer:
Copper ions released from ‘Copper-T’ suppress sperm motility and the fertilizing capacity of sperms.

Question 12.
Which options are available for infertile couples to have child?
Answer:
Infertile couples have many options to have a child such as fertility drugs, modern techniques such as IVE ZIFT, GIFT, ICSI, artificial insemination, IUI, using surrogate mother or taking the sperm from sperm bank.

Question 13.
How many primary spermatocytes and oocytes are required for the formation of 100 spermatozoa and ova?
Answer:
25 Primary spermatocytes and 100 primary oocytes will be required for the formation of 100 spermatozoa and ova respectively.

Question 14.
The entrance of fallopian tube of a lady is blocked. She wants motherhood. Which method will help her?
Answer:
The method of GIFT or Gamete Intra Fallopian Transfer is the method that will help the lady to have a child.

Question 15.
What is the role of birth control pills?
Answer:
Birth control pills are contraceptive pills that check the ovulation by inhibiting the secretion of FSH and LH.

Question 16.
In T.S. of ovary, can all stages of follicles be seen simultaneously?
Answer:
In T.S. of ovary, all the stages of follicles cannot be seen simultaneously. The stage of follicles develop alternately in the ovary as per timing of menstrual cycle under the influence of hormones of pituitary and ovaries.

Question 17.
What will be marriageable age for boy and girl as per the Indian law?
Answer:
As per the Hindu Marriage Act, minimum age for boy must be 21 years and for a girl 18 years, at the time of marriage.

Question 18.
What is MTP Act?
Answer:
MTP Act is for reducing the incidences of illegal abortions and maternal mortalities.

Question 19.
Which is the time period legally allowed by MTP ACT for terminating pregnancy?
Answer:
According to MTP Act, pregnancy may be terminated within first 12 weeks, more than 12 weeks but lesser than 20 weeks.

Give definitions of the following

Question 1.
Amphimixis
Answer:
It is the process which involves the production of offspring by the formation and fusion of gametes.

Question 2.
Gametogenesis
Answer:
The gametogenesis is the process of formation of gametes in sexually reproducing animals.

Question 3.
Spermiogenesis
Answer:
The process of transformation of non-motile and non¬functional spermatid into a functional and motile spermatozoa is called spermiogenesis.

Question 4.
Insemination
Answer:
The process of deposition of semen into the vagina of the female at the time of coitus or sexual intercourse is called insemination.

Question 5.
Cleavage
Answer:
The process of early mitotic division of the zygote to form a multicellular morula stage is called cleavage.

Question 6.
Implantation
Answer:
The process by which the blastocyst after its formation, gets implanted or embedded into the endometrium of the uterus is called implantation.

Question 7.
Gestation
Answer:
The condition of carrying one or more embryos in the uterus is called gestation.

Question 8.
Placenta
Answer:
A flattened, discoidal organ present in the uterus of pregnant mother and which acts as endocrine source and nutrition provider for growing foetus is called placenta.

Question 9.
Lactation
Answer:
The process of secretion of milk in the mammary glands and expelling it through nipples out to provide nourishment to the growing baby is called lactation.

Question 10.
Parturition
Answer:
Parturition is the process of giving birth to a baby.

Question 11.
Amniocentesis
Answer:
Amniocentesis is a process in which amniotic fluid containing foetal cells is collected using a hollow needle inserted into the uterus under ultrasound guidance.

Question 12.
Infertility
Answer:
Infertility is defined as the inability to conceive naturally after (one year of) regular unprotected intercourse.

Question 13.
IVF (In Vitro Fertilization)
Answer:
It is a process of fertilization where an egg is combined with sperm outside the body in a test tube or glass plate to form a zygote under simulated conditions in the laboratory.

Question 14.
Artificial Insemination (AI)
Answer:
It is the technique during which the sperms are collected from the male and artificially introduced into the cervix of female, for the purpose of achieving a pregnancy through in vivo fertilization (inside the body).

Question 15.
Adoption
Answer:
Adoption is a legal process by which a couple or a single parent gets legal rights, privileges and responsibilities that are associated to a biological child for the upbringing of the adopted child.

Give functions of the following

Question 1.
Corpus luteum.
Answer:
Corpus luteum is a secondary endocrine source that produces progesterone for maintaining pregnancy.

Question 2.
Scrotum.
Answer:
Scrotum protects the testis and also acts as thermoregulator.

Question 3.
Acrosome of sperm.
Answer:
Acrosome of the sperm releases hyaluronidase which digests the zona pellucida surrounding the ovum due to which sperm can fertilize the ovum.

Question 4.
Sertoli cells.
Answer:
Sertoli cells provide nourishment and surface to the sperm bundles during their development.

Question 5.
Interstitial cells / Leydig’s cells.
Answer:
Interstitial cells / Leydig’s cells secrete testosterone or androgen which is a male sex hormone.

Question 6.
Prostate gland.
Answer:
Prostate gland secretes prostatic fluid which forms 30% of semen, Citric acid and acid phosphatase present in this fluid protects the sperms from acidic environment of vagina.

Question 7.
Bulbourethral glands.
Answer:
Bulbourethral glands secrete alkaline, viscous mucus like fluid which provides lubrication during copulation.

Question 8.
Bartholin’s glands.
Answer:
Bartholin glands secrete lubricating mucus like fluid which is released in vestibule.

Question 9.
Uterus.
Answer:

1. Uterus receives ovum from fallopian tubes, develops placenta and provides site for implantation of embryo.
2. It provides protection and nourishment to the developing embryo.
3. It also provides path for sperms to ascend.
4. Due to contractions of uterus, baby is expelled out at the time of parturition.

Question 10.
Vagina
Answer:

1. Vagina acts as a copulatory passage.
2. It acts as a birth canal during parturition in normal delivery
3. It provides the passage for menstrual flow.

Name the following

Question 1.
The canal through which the testes descend into scrotum just before birth in human male child.
Answer:
Inguinal canal

Question 2.
The structure where sperms are matured.
Answer:
Epididymis

Question 3.
The part where the sperms are produced in the testes.
Answer:
Germinal epithelium of seminiferous tubules.

Question 4.
The gland in females homologous to Cowper’s gland.
Answer:
Bartholin’s glands or Vestibular glands.

Question 5.
Type of cleavage in human zygote
Answer:
Holoblastic, radial and indeterminate

Question 6.
The developmental stage of human being which gets implanted in the endometrium of uterus.
Answer:
Blastocyst

Question 7.
Name the primates who show presence of menstrual cycle.
Answer:
Human being and Apes like gorilla, chimpanzee, orangutan, etc.

Question 8.
Structures which help in transport of secondary oocyte through uterine tube.
Answer:
Ciliated epithelium

Question 9.
Hormones produced in women only during pregnancy.
Answer:
hCG, HPL (Human Placental Lactogen) and relaxin.

Question 10.
The oral contraceptive pill which is now. a part of the National Family Programme in India.
Answer:
Saheli

Question 11.
The scientific term for the animals giving birth to live young ones.
Answer:
Viviparous

Question 12.
The site of fertilization in woman.
Answer:
Ampulla of fallopian tube

Question 13.
The trophoblast cells lying over the embryonal knob.
Answer:
Cells of Rauber

Question 14.
The muscles which form the wall of scrotum.
Answer:

1. Dartos muscles
2. Cremaster muscles

Question 15.
Names of erectile tissues in penis.
Answer:

1. Corpora cavernosa
2. Corpus spongiosum

Question 16.
Any two copper releasing IUD.
Answer:

1. Copper-T, Cu 7
2. Multiload 375

Question 17.
Any two hormone-releasing IUDs.
Answer:

1. LNG-20
2. Progestaert

Question 18.
Two methods of birth control which have high chances of failure.
Answer:

1. Safe period
2. Lactational amenorrhea

Question 19.
Uterine walls.
Answer:

1. Perimetrium
2. Myometrium
3. Endometrium

Question 20.
Regions of the uterus.
Answer:

1. Fundus
2. Body
3. Cervix

Question 21.
Parts of fallopian tubes.
Answer:

1. Infundibulum
2. Ampulla
3. Isthmus

Question 22.
Layers of Graafian follicle which enclose antrum.
Answer:

1. Theca externa
2. Theca interna
3. Membrana granulosa

Question 23.
Stages of cells in spermatogenesis.
Answer:

1. Spermatogonia
2. Primary spermatocytes
3. Secondary spermatocytes
4. Spermatids
5. Sperms

Question 24.
Stages of cells in oogenesis.
Answer:

1. Oogonia
2. Primary oocytes
3. Secondary oocytes
4. Ootid
5. Ovum

Give significance of the following

Question 1.
Fertilization.
Answer:
Significance of fertilization:

1. Fertilization forms the zygote which eventually produces new offspring.
2. Fertilization restores diploid number of chromosomes in the zygote as two haploid gametes come together in a zygote.
3. During fertilization, centrioles are passed on to the ovum, due to this secondary oocyte can complete meiosis-II. The fertilization thus concludes the process of oogenesis.
4. By fertilization the genetic characters of two parents are mixed. This leads to variation and has significance in evolution.
5. Due to fertilization the sex of young one is determined.

Question 2.
Implantation.
Answer:
Gestation becomes possible due to implantation. Implantation protects the embryo and helps it to derive nourishment from the mother’s body through placenta.

Question 3.
Corpus luteum.
Answer:

1. Corpus luteum is the temporary source of female hormone, progesterone.
2. Corpus luteum is formed from empty Graafian follicle after the process of ovulation.
3. Due to progesterone secreted from corpus luteum, the endometrial wall of uterus undergoes repair and increase in thickness.
4. Progesterone is a gestational hormone and thus pregnancy is maintained if corpus luteum is well functional.

Question 4.
Fertilization membrane.
Answer:
Fertilization membrane prevents any further entry of other sperms into the egg, i.e. polyspermy is avoided.

Question 5.
Gastrulation.
Answer:

1. Due to the process of gastrulation, three germinal layers, viz. ectoderm, mesoderm and endoderm are formed.
2. Cells of embryonal knob become embryonic disc which develop into embryo due to gastrulation.
3. Gastrulation is necessary for the formation of amniotic cavity which is filled with amniotic fluid.

Question 6.
Trophoblast of blastocyst.
Answer:

1. Trophoblast cells help in absorbing nutrition for the developing embryo.
2. Trophoblast cells at the embryonal knob (cells of Rauber) help in implantation of blastocyst.
3. Synctiotrophoblast helps in implantation of fertilized ovum in the uterine endometrium.

Question 7.
hCG [human chorionic gonadotropin].
Answer:
hCG [human chorionic gonadotropin] is secreted in the pregnant female to extend the life of corpus luteum and stimulates its secretory activity. Presence of hCG in maternal blood and urine is an indication of pregnancy.

Question 8.
Colostrum.
Answer:

1. Colostrum is the first milk which is sticky and yellowish secreted by the mammary glands soon after the parturition.
2. Being high protein in its content, it nourishes the newly born child.
3. The antibodies present in it helps in developing resistance for the newborn baby at a time when its own immune response is not fully developed.

Distinguish between the following

Question 1.
Asexual reproduction and Sexual reproduction.
Answer:

Sexual reproduction	Asexual reproduction
1. Asexual reproduction requires single parent.	1. Sexual reproduction needs two different parents.
2. Meiosis does not take place in asexual reproduction. Only mitosis takes place.	2. Sexual reproduction involves meiosis and mitosis.
3. Gamete formation, fertilization and zygote formation does not take place.	3. Gamete formation, fertilization and zygote formation are important processes in sexual reproduction.
4. Progeny and parent Eire identical genetically.	4. Progeny and parents are genetically dissimilar.
5. Large number of progeny is developed by asexual reproduction. E.g. Spore formation, gemmule formation, budding, regeneration are the types of a sexual reproduction.	5. Limited number of progeny is developed by sexual reproduction. E.g. Sexual reproduction is only by a single method.

Question 2.
Primary sex organs and Secondary sex organs.
Answer:

Primary sex organs	Secondary / Accessory sex organs
1. Primary sex organs produce gametes.	1. Secondary sex organs do not produce gametes.
2. Primary sex organs secrete sex hormones.	2. Secondary sex organs do not secrete sex hormones.
3. Development of these organs is under the control of Gonadotropins released from Pituitary. E.g. Testes in male and Ovaries in females.	3. Development of these organs is under the control of estrogen and progesterone in females and testosterone in males. Eg. Prostate, seminal vesicles, vas deferens in males. Fallopian tubes, uterus and vagina in females.

Question 3.
Vasa efferentia and Vasa deferentia.
Answer:

Vasa efferentia	Vasa deferentia
1. Vasa efferentia arise from the rete testes and enter the epididymis.	1. Vasa deferentia arise from the epididymis and form ejaculatory duct after the union with seminal duct.
2. They are present in 15-20 number and are fine convoluted ductules.	2. They are thick and coiled ductules present in a single pair.
3. The spermatozoa are carried from rete testis to epididymis by vasa efferentia.	3. The spermatozoa are carried from epididymis to ejaculatory ducts by vasa deferentia.

Question 4.
Graafian follicle and Corpus luteum.
Answer:

Graafian follicle	Corpus luteum
1. Graafian follicle is produced by the maturation of the primary follicle.	1. Corpus luteum is produced by the cells of ruptured Graafian follicle.
2. It is formed in the ovary before ovulation.	2. It is formed in the ovary after ovulation.
3. It produces the hormone estrogen.	3. It produces the hormone progesterone.
4. It has secondary oocyte surrounded by follicle cells.	4. It has only follicle cells.

Question 5.
Menarche and Menopause.
Answer:

Menarche	Menopause
1. Menarche is the beginning of menstrual cycle.	1. Menopause is the stoppage of menstrual cycle.
2. Menarche is at the age of 10 to 14.	2. Menopause is at the age of 45 to 50.
3. Menarche begins with secretion of FSH and LH.	3. Menopause is caused due to decline of FSH and LH secretion.
4. Menarche is the beginning of the reproductive period.	4. Menopause is the end of the reproductive period.

Question 6.
Proliferative Phase and Secretory Phase.
Answer:

Proliferative Phase	Secretory Phase
1. Proliferative phase begins with the repair of endometrium.	1. Secretory phase begins with ovulation.
2. Time required for proliferative phase is 5th to 13th day of menstrual cycle.	2. Time required for secretory phase is 15th to 28th day of menstrual cycle.
3. Proliferative phase always ends with ovulation.	3. Secretory phase ends with menstruation if egg is not fertilized. It continues further if egg is fertilized.
4. Proliferative phase is in uterus which coincides . with follicular phase in ovary during which there is formation of Graafian follicle.	4. Secretory phase is in uterus which coincides with luteal phase in ovary during which there is formation of corpus luteum.
5. Proliferative phase is controlled by FSH from anterior pituitary.	5. Secretory phase is controlled by LH from anterior pituitary.
6. Hormone estrogen is secreted during this phase.	6. Hormone progesterone is secreted during this phase.
7. It causes the development of blood vessels and thickening of endometrium of uterus.	7. It causes further thickening and secretory activity of the glands of endometrium of uterus.

Question 7.
Spermatogenesis and Oogenesis.
Answer:

Spermatogenesis	Oogenesis
1. Spermatogenesis takes place in testis in mature and fertile males.	1. Oogenesis takes place in ovaries in mature and fertile females.
2. From one spermatogonium four haploid sperms are formed during spermatogenesis.	2. From one oogonium one haploid ovum and a polar body is formed during oogenesis.
3. Spermatid developed undergoes metamorphosis in the process of spermiogenesis.	3. There is no such process of metamorphosis in oogenesis.
4. Spermatid development takes place which later becomes a functional sperm.	4. Ootid development does not take place during oogenesis. It develops only after fertilization.
5. Spermatogonia, primary and secondary spermatocytes and spermatid are the stages of sperms formed during spermatogenesis.	5. Oogonia, primary and secondary oocytes are the stages formed during oogenesis. Ootid formation occurs only after fertilization.

Question 8.
Zona pellucida and Corona radiata.
Answer:

Zona pellucida	Corona radiata
1. Zona pellucida is inner, thin and transparent layer surrounding the secondary oocyte.	1. Corona radiata is the outer thick layer surrounding the secondary oocyte.
2. Zona pellucida is a non-cellular layer.	2. Corona radiata is a cellular layer.
3. Zona pellucida is secreted by the ovum itself.	3. Corona radiata is formed by follicular cells which are glued together by hyaluronic acid.
4. Zona pellucida is retained for more time after fertilization till the ovum gets implanted in the uterus.	4. Corona radiata is retained till the ovum gets fertilized.
5. Zona pellucida is digested by zona lysine or acrosin at the time of fertilization.	5. Corona radiata is digested by hyaluronidase enzyme at the time of fertilization.

Question 9.
Morula and Blastula.
Answer:

Morula	Blastula
1. Morula is the embryonic stage formed after the completion of cleavage.	1. Blastula is the embryonic stage formed after the completion of blastulation.
2. Morula is formed 4 to 6 days after the fertilization.	2. Blastula is formed 6 to 7 days after the fertilization.
3. Morula consists of 16 cells.	3. Blastula consists of more than 64 cells.
4. Morula is solid ball of cells.	4. Blastula is a hollow ball of cells.
5. Morula stage is passed in fallopian tube, once it reaches uterus, it starts developing into the next stage.	5. Blastula after reaching the uterus is implanted on the wall of uterus.
6. Morula does not have any distinction of its inner cell structure.	6. Blastula has a blastocoel, trophoblast and inner cell mass.

Question 10.
Blastula and Gastrula
OR
Give two differences between blastula and gastrula.
Answer:

Blastula	Gastrula
1. Blastula is formed from morula on 7th day after fertilization.	1. Gastrula is formed from blastula 15 days after fertilization.
2. Blastula has a blastocoel.	2. Gastrula has a gastrocoel or archenteron.
3. Blastula is produced by the process of blastulation.	3. Gastrula is produced by the process of gastrulation.
4. Blastula undergoes implantation followed by gastrulation.	4. Gastrula undergoes morphogenesis and then forms germs layers.
5. During blastula formation there is no movement of cells.	5. Gastrula formation results from the morphogenetic movement of cells.

Give reasons

Question 1.
Testes are located outside the body cavity in scrotal sacs.
Answer:

1. During early foetal life, the testes develop in the lumbar region of the abdominal cavity just below the kidney but during seventh month of development, they descend permanently into the respective scrotal sacs through a passage called inguinal canal.
2. For the development of the sperm, lesser temperature than the body temperature is required.
3. If the testes remain in the abdominal cavity, then the sperm production does not take place.
4. This may result in impotency. Therefore, testes are located outside the body cavity.

Question 2.
Urethra is also called urinogenital duct in males.
Answer:

1. Urinogenital duct means common duct for urine and the genital products.
2. In males, the penis lodges urethra throughout its entire length, through which urine as well as semen are given out of the body during urination or copulation.
3. Since the urethra carries both urine and semen, it is called urinogenital duct.

Question 3.
Proliferative phase is also called follicular phase.
Answer:

1. Proliferative phase means there is proliferation of endometrial cells in the uterus. Follicular means there is growth of ovarian follicles in the ovaries. Both these phases are simultaneous.
2. The follicular phase of ovaries is due to effect of FSH from adenohypophysis.
3. The ovaries follicles grow due to FSH and start secreting estrogen.
4. This estrogen from ovaries bring proliferative effect on the uterus.

Question 4.
Missing of menses is the first indication of pregnancy.
Answer:

1. Menstruation occurs if there is no fertilization of ovum.
2. The endometrium of uterus along with unfertilized egg is given out in the form of menstrual flow.
3. The sloughing off uterine endometrium takes place due to degeneration of corpus luteum.
4. In the absence of functional corpus luteum progesterone levels fall down. However, if the ovum is fertilized, the corpus luteum is maintained and it secretes progesterone which maintains the uterine endometrium. In such case, further growth of ovarian follicles and ovulation remains suspended and woman is said to be pregnant.
5. Endometrial wall of uterus now thickens and helps in the growth of placenta. Thus during pregnancy, menses will not take place.

Question 5.
Progesterone is called pregnancy hormone.
Answer:

1. Progesterone is secreted from corpus luteum which is formed from empty ovarian follicle after the ovulation.
2. Progesterone has the capacity to maintain pregnancy.
3. It acts on uterine endometrium and causes it to proliferate and develop in thickness.
4. Corpus luteum keeps on secreting progesterone till the placenta takes up the function of secreting the same.

Question 6.
Human female has restricted reproductive life.
Answer:

1. In human female, the reproductive period is about 30 – 33 years.
2. There is menarche at the age of about 13 and menopause at the age of 45-50.
3. During this span of 30 years, ovaries secrete sex hormones like estrogen and progesterone. After menopause this secretion is suspended.
4. Due to changes in hormonal level, human females cannot produce eggs later. Moreover, eggs in her ovaries are utilized by the age of 45.
5. Human female, therefore, has restricted reproductive period.

Question 7.
Zona pellucid is retained for sometime after fertilization.
Answer:

1. Fertilization of the ovum takes place in fallopian tube where it starts cleavages immediately.
2. Zona pellucida which remains on the surface of the ovum prevents the implantation of the blastocyst at an abnormal site such as fallopian tube.
3. Zona pellucida keeps the sticky and phagocytic trophoblast cells unexposed till the ovum reaches the uterine lumen.
4. Zona pellucida also protects the ovum. Therefore zona pellucida is retained for some time after fertilization.

Question 8.
The acrosome of sperm secretes an enzyme called hyaluronidase at the time of fertilization.
Answer:

1. The enzyme hyaluronidase secreted by acrosome of sperm dissolves the membranous covering of the ovum to facilitate the entry of sperm into the ovum.
2. It is a lytic enzyme causing lysis of egg membrane.
3. Owing to this, the acrosome of sperm secretes an enzyme called hyaluronidase at the time of fertilization.

Question 9.
The middle part of the human sperm is characterized by the presence of a number of mitochondria.
Answer:

1. Mitochondria provide energy required by sperms for their agile movement.
2. The agile movement of sperms helps them to reach the vicinity of the ovum at the time of fertilization.
3. Owing to this, the middle part of the human sperm is characterised by the presence of a number of mitochondria.

Question 10.
The size of morula remains almost same as that of ovum.
Answer:

1. The layer zone pellucida is retained around the embryo and thus, there is no change in the overall size from zygote to morula.
2. This layer is important because it prevents the implantation of the blastocyst at an abnormal site such as fallopian tube.
3. Though the number of blastomeres increase, the size of morula remains almost same as that of ovum till it reaches the uterus by the end of the day 4.

Question 11.
Placenta serves as the nutritive, respiratory and excretory organ of the embryo.
Answer:

1. Between the foetus and mother there is exchange of several materials. Food in the form of glucose, amino acids, simple proteins, lipids, mineral, salts, vitamins and hormones, antibodies, etc. is sent to foetus by maternal circulation.
2. Oxygen from mother’s blood is also given to the foetus.
3. The foetal metabolic wastes such as carbon dioxide, urea and water pass from foetus into the maternal blood.
4. This exchange takes place through the placenta.
5. In the placenta, foetal blood comes very close to maternal blood to permit these exchanges. Therefore placenta is said to serve as the nutritive, respiratory and excretory organ of the embryo.

Write short notes

Question 1.
Graafian follicle.
Answer:

1. Graafian follicle is a mature ovarian follicle.
2. There are following protective layers on the Graffian follicle : The outermost protective and fibrous covering, theca externa. Theca interna is the next layer which can secrete hormone estrogen.
3. Next to theca interna, there is membrana granulosa which forms discus proligerous and the corona radiata layer.
4. Graafian follicle contains an eccentric secondary oocyte. The oocyte is surrounded by a vitelline membrane which produces zona pellucida layer.
5. In the centre there is antrum which is filled with liquor folliculi fluid.

Question 2.
Mammary glands.
Answer:

1. Mammary glands are accessory organs of female reproductive system. These glands are essential for lactation after parturition.
2. They are modified sweat glands present in the subcutaneous tissue of the anterior thorax. They are in the pectoral region in the location between 2nd to 6th rib.
3. Each mammary gland consists of fatty connective tissue and many lactiferous ducts.
4. Each breast has glandular tissue which is divided into 15-20 irregularly shaped mammary lobes. Each lobe has an alveolar glands and lactiferous duct.
5. Milk is secreted by alveolar glands and it is stored in the lumen of alveoli. The alveoli open into mammary tubules and these in turn forms a mammary duct.
6. All the lactiferous ducts converge towards the nipple.
7. Nipple is surrounded by a dark brown coloured and circular area of the skin called areola.

Question 3.
Structure of sperm.
Answer:

1. Sperm is microscopic, elongated haploid motile male gamete produced by spermatogenesis.
2. It measures to about 0.055 mm or 60y in length.
3. The sperm consists of head, neck, middle piece and tail.

Head:

1. Head is the main part which is flat and oval and has a large nucleus and an acrosome.
2. Acrosome is formed from Golgi complex. It secretes enzyme hyaluronidase which helps in penetration of the egg during fertilization.
3. The acrosome and anterior half of nucleus is covered by a fibrillar sheath.

Neck : Neck is short region having two centrioles.

1. The proximal centriole plays a role in first cleavage of zygote.
2. The axial filament of the sperm is formed by the distal centriole.

Middle piece:

1. Middle piece acts as a power house for sperm.
2. It bears many spirally coiled mitochondria or Nebenkern around the axial filament.
3. The mitochondria supply energy for the sperm to swim in the female genital tract with a speed of about 1.5 to 3 mm per minute.
4. Posterior half of nucleus, neck and middle piece of sperm are covered by a sheath.

Tail:

1. The tail is formed of cytoplasm and is long, slender and tapering structure.
2. The axial filament is a fine thread-like structure that arises from the distal centriole and traverses the middle piece and tail.
3. Nine accessory fibres are present surrounding the two central longitudinal axial filaments.
4. Tail lashes and helps the spermatozoa to swim.

Question 4.
Structure of secondary oocyte.
Answer:

1. The unfertilized egg released through ovary at the time of ovulation is a secondary oocyte.
2. It is rounded, non-motile and haploid, non- cleidoic and microlecithal female gamete.
3. The size is approximately 0.1 mm (100 microns).
4. It has abundant cytoplasm called ooplasm which contains a large eccentric and prominent nucleus called germinal vesicle.
5. Centrioles are absent in secondary oocyte.
6. Various coverings seen around the oocyte are (i) vitelline membrane (ii) zona pellucida (iii) Corona radiata.
7. The cells are glued together with hyaluronic acid. Between vitelline membrane and zona pellucida, there is perivitelline space which lodges first polar body. This end is called 5 animal pole and the opposite is called vegetal pole.

Question 5.
Implantation
Answer:

1. Implantation is the process by which the blastocyst is embedded into the endometrium of uterus in the fundus region.
2. The implantation starts 7 days after fertilization and completed by the end of 10th day.
3. The trophoblast cells of blastocyst at the embryonal knob can stick to the uterine endometrium. The trophoblast layer then divides into inner cytotrophoblast and outer syncytiotrophoblast due to contact with endometrial cells.
4. Cytotrophoblast is the inner layer whose cells retain their cell boundaries.
5. Syncytiotrophoblast is the outer layer of cells without plasma membrane. The cells of syncytiotrophoblast appear multinucleate. This layer projects invasively into the endometrium and destroys endometrial cells by releasing lytic enzymes. Due to this blastocyst is buried deeply in the endometrium.

Question 6.
Fate of three germinal layers.
Answer:
Fate of germinal layers : The embryo after gastrulation develops the three germ layers, viz., ectoderm, mesoderm and endoderm. Later a process of histogenesis starts which leads to the development of different tissues and organs.
(i) Fate of ectoderm : Following tissues, structures and organs develop from the ectoderm : Epidermis of the skin, epidermal derivatives such as

1. hair and nails
2. sweat glands
3. conjunctiva
4. cornea
5. lens
6. retina
7. internal and external ear
8. enamel of teeth
9. nasal cavity
10. adrenal medulla
11. stomodaeum and proctodaeum
12. neurohypophysis and
13. entire nervous system.

(ii) Fate of mesoderm : The mesoderm forms the following derivatives:

1. All types of muscles
2. connective tissue
3. dermis of skin
4. adrenal cortex
5. kidney
6. circulatory system
7. heart
8. blood vessels
9. blood
10. lymphatic vessels
11. middle ear and
12. dentine of teeth.

(iii) Fate of endoderm : The following organs develop from the endoderm:

1. Epithelium of gut from pharynx to colon
2. glands of stomach and intestine
3. tongue and tonsils
4. lungs, trachea, bronchi, larynx, etc.
5. urinary bladder, vestibule and vagina
6. liver and pancreas
7. adenohypophysis
8. thymus, thyroid and parathyroid
9. eustachian tube
10. epithelium of urethra and associated glands.

Question 7.
Placenta.
Answer:

1. Placenta is a temporary organ derived from the tissues of the foetus as well as mother.
2. Human placenta is called chorionic placenta as it is made up of chorion which is an extra-embryonic membrane.
3. Blood vessels from the allantois vascularize the placenta. Branching villi emerge from the chorion and penetrate in the corresponding pits which are located in the uterine wall.
4. There are two parts of placenta, viz. foetal placenta and maternal placenta.
5. Foetal placenta is formed of chorionic villi.
6. Maternal placenta is formed of uterine wall which is in intimate contact with the chorionic villi.
7. Chorionic villi receive the blood from the embryo by umbilical artery. Umbilical vein returns the blood back to the embryo.
8. Human placenta is said to be haemochorial because a part of placenta is from foetus which has chorionic villi. The other highly vascularized part is from uterine wall of mother. Thus foetal and maternal placenta together is called haemocorial placenta.

Question 8.
Intratuterine devices (IUDs).
Answer:

1. IUDs are plastic or metal objects which act as contraceptive devices. They are placed into the uterus by a doctor or trained nurse.
2. E.g. Lippe’s loop, copper releasing IUDs (Cu-T, Cu-7, multiload 375) and hormone releasing IUDs (LNG-20, Progestaert).
3. Plastic double ‘S’ loop is called Lippe’s loop which stimulates accumulation of macrophages in the uterine cavity by attracting them. As phagocytosis increases the sperms are destroyed. Thus it acts as a contraceptive.
4. Copper releasing IUDs suppress sperm motility and the fertilizing capacity of sperms.
5. The hormone releasing IUDs make the : uterus unsuitable for implantation and ; cervix hostile to the sperms.
6. Their presence in the uterus acts as a minor irritant and thus makes the ovum to move quickly out of the body.
7. However, IUD can cause infection and occasional haemorrhage. It can cause discomfort for woman and may get spontaneously expelled out.

Question 9.
Physiological (Oral) Contraceptive « Devices.
Answer:

1. Physiological devices are in the form of oral contraceptive pills or birth control pills. 5 They are hormonal preparations and check ovulation by inhibiting the secretion of follicle stimulating hormone and luteinizing hormone.
2. Woman who is using pills does not release ovum at the time of ovulation and therefore conception does not occur.
3. Birth control pills have side effects such as nausea, breast tenderness, weight gain and ‘break through’ bleeding, i.e. slight bleeding between the menstrual periods. These health hazards are due to synthetic hormones.
4. These pills also alter the quality of cervical J mucus to prevent the entry of sperms.
5. The birth control pills contain progesterone and estrogen. Mala-D to be taken daily and Saheli to be taken weekly are two common birth control pills in India. These pills are non-steroidal.

Question 10.
Fate of trophoblast cells of blastocyst.
Answer:

1. Trophoblast cells do not form any part of the embryo proper.
2. They form ectoderm of the extra-embryonic membrane called chorion.
3. Chorion helps in supply of oxygen and nutrients to foetus from mother’s body. CO₂ and nitrogenous wastes are collected from foetus and passed in mother’s blood.
4. Thus, these cells have an important role in formation of placenta.

Question 11.
Medical Termination of Pregnancy (MTP).
Answer:

1. MTP or Medical Termination of Pregnancy is voluntary termination of pregnancy under medical supervision. It is an induced abortion.
2. Only during first trimester, MTP is safe for mother’s health.
3. Upon amniocentesis examination, if abnormality is detected, usually MTP is performed.
4. Government of India has legalized MTP There was MTP Act in 1971, which was later amended in 2017, to prevent its misuse, especially female foeticide should never be done through MTP
5. As per MTP Act, the procedure can be done only in first 12 weeks and never after 20 weeks of pregnancy.

Question 12.
Amniocentesis
Answer:

1. In amniocentesis, amniotic fluid containing foetal cells is collected using a hollow needle. This needle is inserted into the uterus of pregnant mother, under ultrasound guidance.
2. The chromosomes from the foetal cells are sujected to karyotyping. This helps to detect abnormalities in the developing foetus.
3. Amniocentesis is misused to determine the sex of the unborn child. This is illegal in India because it results into female foeticide.
4. Another risks involved in amniocentesis are miscarriage, needle injury to foetus, leaking amniotic fluid, infection, etc.
5. As per MTP Act (1971) the misuse of amniocentesis is curtailed.

Question 13.
ZIFT [Zygote Intra Fallopian Transfer].
Answer:

1. If there is a blockage in the fallopian tubes due to which fertilization is prevented, then ZIFT treatment is used.
2. The oocyte is removed form woman’s ovary. This oocyte is fertilized outside the body under sterile conditions with the known sperms. This forms zygote. This is In Vitro Fertilization (IVF).
3. Later the zygote is transferred in fallopian tube to achieve pregnancy.

Question 14.
GIFT [Gamete Intra Fallopian Transfer].
Answer:

1. When the oocyte is collected from donor and transferred into the fallopian tube of another female, the technique is called GIFT. This female provides suitable environment for further development.
2. When the entrance or upper segments of the fallopian tubes is blocked, this technique is used.
3. Ooocytes and sperms are directly injected into regions of the fallopian tubes. Here fertilization takes place forming a blastocyst. It later enters the uterus for implantation.
4. GIFT is successful in only 30 per cent cases.

Question 15.
Sterilization operations.
Answer:

1. Sterilization operations are the permanent means for the birth control. These can be performed on both the sexes. Usually these are performed after the couple does not desire another child.
2. These surgical interventions block the gamete transport and thus prevents the pregnancy.
3. Sterilization operation in males is called vasectomy while in females it is called tubectomy.
4. In vasectomy the vas deferens are tied and cut. In tubectomy fallopian tubes are ligated or cut.

Question 16.
Gonorrhoea.
Answer:
(1) Gonorrhoea is a sexually transmitted veneral disease caused by Diplococcus bacterium, Neisseria gonorrhoea.

(2) The incubation period is 2 to 14 days in males and 7 to 21 days in females.

(3) Infection sites are mucous membrane of urino-genital tract, rectum, throat and eye.

(4) Males show following symptoms : Partial blockage of urethra and reproductive ducts, pus from penis, pain and burning sensation : during urination, arthritis, etc.

(5) Symptoms in female include, pelvic inflammation of urinary tract, sterility, arthritis. The children born to affected mother suffer from gonococcal ophthalmia, In girl-child, there is occurrence of gonococcal vulvovaginitis before puberty.

(6) Preventive measures for gonorrhoea are as follows:

• Sexual hygiene
• Use of condom during coitus.
• Sex with unknown partner or multiple partners should be avoided.

(7) Gonorrhoea can be treated with Cefixime which is antibiotic.

Short-answer Questions

Question 1.
What are sexual dimorphic characters? Enlist these characters in human male and female.
Answer:
Sexual dimorphism is the phenomena in which the sexes of the individual can be identified externally. In human beings, even in infancy there is sexual dimorphism, by which one can identify the sex of the infant.

But when the male or female reaches puberty, then secondary sexual characters are developed due to sex hormones. These characters are called sexual dimorphic characters.
(i) Secondary sexual characters in males:

1. Presence of beard, Moustache.
2. Hair on the Chest, Axillary and Pubic Region.
3. Muscular body.
4. Enlarged larynx (Adam’s apple).

(ii) Secondary sexual characters in females:

1. Breast development.
2. Broadening of pelvis.
3. High pitched voice.

Question 2.
Describe the duct system that transports the sperms from seminiferous tubules to the exterior.
Answer:
(1) All the seminiferous tubules present in the testis show posterior network of tubules called rete testis. Vasa efferentia are the fine tubules which are 12-20 in number, are seen arising from rete testis. From testis to epididymis, the sperm transport is done by vasa efferentia.

(2) Epididymis has three parts, caput, corpus and cauda epididymis. In this long and highly coiled tube sperms undergo physiological maturation.

(3) Then from here sperms enter into vas deferens, which is a tube that arise from epididymis enters the abdominal cavity. On its course, later it joins the duct of seminal vesicle. Both together form the ejaculatory duct.

(4) Ejaculatory duct passes through the prostate gland and then opens into the urethra. Urethra is a common passage for urine and semen and hence it is also called urinogenital duct.

(5) Urethra passes through penis and opens to the outside by an opening called the urethral meatus or urethral orifice.

(6) Thus sperms are transported through vas deferens into urethra via ejaculatory duct and then to the outside through urethral orifice.

Question 3.
What is semen? Describe the composition of semen.
Answer:
(1) Semen is the viscous, alkaline and milky fluid having pH 7.2 to 7.7 ejaculated during sexual intercourse by male.

(2) A single ejaculation of semen i.e. 2.5 to 4 ml semen contains about 400 millions of sperms.

(3) Semen consists of sperms suspended in secretions of the epididymis and the accessory glands (seminal vesicles, prostate gland and Cowper’s gland). The semen nourishes the sperms by fructose, neutralizes acidity by Ca⁺⁺, ions and bicarbonates and also activates them for movement due to prostaglandins.

Question 4.
Describe in detail the external genitalia of human female reproductive system.
Answer:
The external genital organs of female are located external to the vagina. They have collective name, ‘vulva’ or pudendum. Following are the parts of vulva.
(1) Labia majora : Labia majora are homologous to scrotum of males. They are two large folds which form the boundary of the vulva. They are composed of skin, fibrous tissue and fat. These Eire prominent and longitudinal folds on right and left sides of the vestibule.

(2) Labia minora : Smaller and thinner lip-like folds located just medially are labia minora. Posteriorly the labia minora are fused together to form the fourchette.

(3) Mons veneris : Mons veneris is fleshy elevation above the labia majora.

(4) Clitoris : It is present at the anterior end of the labia minora. It shows the presence of erectile tissues.

(5) Vestibule : Vestibule is a median vertical depression of vulva enclosing vagina and urethral opening.

(6) Hymen : Hymen is a thin layer of mucous membrane which partially occludes the opening of the vagina.

(7) Vestibular glands:

1. Vestibular glands or Bartholin’s glands are homologous to the Cowper’s glands of the male.
2. These are paired glands situated on either side of the vaginal opening, secreting lubricating fluid.

Question 5.
How is puberty attained in females? Will a female normally remain reproductively capable even after age 50? If not then what makes her incapable?
Answer:
(1) Puberty is achieved due to gonadotropins such as FSH and LH secreted by the anterior pituitary. These hormones stimulate the ovaries. The ovaries in turn produce estrogen and progesterone, which brings about secondary sexual characters in female. Thus she attains the puberty. The beginning of menstrual cycle or menarche takes place due to these hormonal changes at about 10 to 14 years.

(2) But the women do not remain reproductively active after the age of 50 due to hormonal imbalance. This is called menopause or cessation of reproductive cycles. Absence of enough gonadotropins and unresponsive ovarian cells cause menopause at 45 to 50 years of age.

Question 6.
Why is menstruation painful in some women?
Answer:

1. The menstruation is painful in some women as the muscles in the uterus contract or tighten.
2. Women who experience painful periods can have higher levels of prostaglandins, a natural body chemical that causes contractions of the uterus and blood vessels.
3. Some women have a build-up of prostaglandins which means they experience stronger contractions and therefore due to spasmodic pain in some women menstruation is more painful.
4. Endometrial sloughing that takes at the time of menstruation also causes painful discomfort.

Question 7.
Why is it said that consumption of mother’s milk is safety for the newborn?
Answer:
Consumption of mother’s milk is safety for the newborn because of the following reasons:

1. Mother’s milk is the perfect food for babies in the first months of their lives. With the exception of vitamin D, it contains all the nutrients an infant needs.
2. Mother’s milk supplies antibodies [IgA] that protect the baby’s body organs from infections. Mother’s milk provides immunity and also help in maturation of the infant’s immune system which are lacking in ordinary milk. Natural acquired passive immunity is obtained only through mother’s milk.
3. Feeding of mother’s milk reduces the risk of overweight and obesity during childhood.
4. It also creates the bond between mother and child.

Question 8.
Which hygienic practices should be followed by the female during menstruation ?
Answer:
The following personal hygienic practices should be followed by the female during menstruation:

1. Keeping the pubic area clean.
2. Changing the sanitary napkin every 4-5 hours.
3. Reducing risk of infections by maintaining hygiene.
4. Proper disposal of soiled sanitary napkin.
5. Not to use damp and dirty clothes which can cause infections and bad odour. A sanitary napkin which is not changed in time can act as a perfect environment for rapid growth of infectious bacteria.

Question 9.
How can the goals of RCH be achieved?
Answer:
The goads of RCH can be achieved by the following ways:

1. Sex education in schools is introduced. Proper and scientific information about sexual organs and safe sexual acts should be given to students. They should be made aware of sexually transmitted diseases (STD, AIDS), and problems related to adolescence.
2. Audio-visual and the print media should be used by government and non-government organisations for creating awareness about reproductive health.
3. Younger generation should be educated about family planning measures, pre-natal and post-natal care of women and care of infant with knowledge about importance of breastfeeding.
4. Awareness should be spread about problems arising due to uncontrolled population growth, sex abuse and sex related crimes. Necessary steps to prevent these to be taken.
5. Statutory ban on amniocentesis for sex determination is practised. This should be known by all.
6. Details of child immunization programmes should be understood.
7. New parents should get the training for new born care so that infant and maternal mortality rate can be reduced.

Question 10.
How do addictions like smoking, alcoholism and drug abuse contribute in causing infertility in men?
Answer:

1. Tobacco, marijuana and other drugs, smoking may cause infertility in both men and women.
2. Nicotine blocks the production of sperm and decreases the size of testicles.
3. Alcoholism by men interferes with the synthesis of testosterone and has an impact on sperm count.
4. Use of cocaine or marijuana may temporarily reduce the number and quality of sperm.

Question 11.
Jayesh, a young married man of 26 years is suffering from T.B. for the last 2 years. He and his wife are desirous of a child but unable to have one, what could be the possible reason? Explain.
Answer:
Jayesh, though young, is suffering from TB for last 2 years. His wife is unable to conceive the child may be due to following reasons:

1. Tuberculosis disrupts sexual and reproductive function in patients.
2. Moreover T.B. patients have to take not less than 4 anti-TB drugs simultaneously for a long time.
3. These are basically a very high dose antibiotics which may hamper formation of sperms. In this way the anti-tuberculosis drugs may negatively influence on sexual function.
4. Pulmonary TB patient shows, deterioration of all parameters of copulatory act, from sexual desire to orgasm and thus the couple is unable to conceive.
5. Infertility is one of the most common symptoms of genital tuberculosis.

Question 12.
Neeta is 45 years old and the doctor advised her not to go for such a late pregnancy. She however wants to be the biological mother of a child without herself getting pregnant. Is this possible and how?
Answer:
(1) Neeta being 45 years old, she is approaching menopause. Therefore, she will be advised by the doctor to take the help of the modern remedial technique called surrogacy.

(2) In this technique the embryo is formed using intended father’s sperm and intended mother’s egg by In Vitro Fertilization (IVF) technique and then that embryo is implanted in a surrogate mother, sometimes called a gestational carrier.

(3) In surrogacy there is legal arrangement where the surrogate mother agrees to bear child for a couple. Remains pregnant with all the care and nourishment. Later she delivers a baby and hands it over to biological mother.

Chart based /Table based questions

Question 1.
Complete the following chart and rewrite

Female Reproductive Organs	Homology to Male Reproductive Organs
1. Labia majora	————–
2. ————-	Bulbourethral glands/ Cowper’s gland
3. Clitoris	—————

Answer:

Female Reproductive Organs	Homology to Male Reproductive Organs
1. Labia majora	Scrotum
2. Bartholin’s gland/ Vestibular gland	Bulbourethral glands/ Cowper’s gland
3. Clitoris	Penis

Question 2.

Hormones	Functions
1. Testosterone	————–
2. ————-	Stimulates contractions uterine during parturition
3. Progesterone	—————

Answer:

Hormones	Functions
1. Testosterone	Stimulates spermatogenesis
2. Oxytocin	Stimulates contractions uterine during parturition
3. Progesterone	Maintain endometrium of uterus during secretory phase and gestation.

Question 3.
Complete the following chart and rewrite

Hormones	Functions
1. Rapid regeneration of endometrium and maturation of Graafian follicle	————–
2. Secretion of endometrial glands and increased secretion of progesterone	————–
3. Breakdown of endometrium in absence of fertilization	————-

Answer:

Hormones	Functions
1. Rapid regeneration of endometrium and maturation of Graafian follicle	Proliferative phase / Follicular phase
2. Secretion of endometrial glands and increased secretion of progesterone	Secretory phase / Luteal phase
3. Breakdown of endometrium in absence of fertilization	Menstrual phase

Diagram based questions

Question 1.
Sketch and label Human male reproductive system.
Answer:

Question 2.
Label the given male reproductive system you have studied.

Answer:

1. Seminal vesicle
2. Ejaculatory duct
3. Cowper’s glands
4. Urethra
5. Epididymis
6. Testis
7. Urinary bladder
8. Prostate gland
9. Vas deferens
10. Penis

Question 3.
Sketch and label human female reproductive system.
Answer:

Question 4.
Give labels to given diagram of female reproductive system.

Answer:

1. Fallopian tube
2. Fundus of Uterus
3. Ampulla of fallopian tube
4. Ovarian ligament
5. Uterus
6. Ovary
7. Infundibulum with fimbriae
8. Endometrium of uterus
9. Cervix
10. Vagina

Question 5.
Sketch and label Seminiferous tubules as seen in T.S. of testis.
Answer:

Question 6.
Identify ‘A’ and ‘B’ in the diagram below and mention their functions.

Answer:
(1) A : Seminiferous tubule
Function : Seminiferous tubules produce sperms by spermatogenesis.

(2) B : Vas deferens
Function : Vas deferens carry sperm from epididymis to ejaculatory duct.

Question 7.
Sketch and label – T.S. of ovary.
Answer:

Question 8.
Sketch and label sectional view of mammary gland.
Answer:

Question 9.
Sketch and label – Graafian follicle.
Answer:

Question 10.
Sketch and label – Process spermatogenesis.
Answer:

Question 11.
Sketch and label process of oogenesis.
Answer:

Question 12.
Give the name and functions of ‘A’ and ‘B’ from the diagram given below

Answer:
(1) A is acrosome.
Function of acrosome : Acrosome produces lytic enzyme, hyalourinidase and thus helps in the penetration of the egg during fertilization.

(2) B is tail of the human sperm.
Function of tail : Tail lashes continuously and helps the movement of the sperm in the female genital tract.

Question 13.
The diagram represents a surgical sterilization method in males. Study the same and answer the questions that follow

1. Give the name of the surgical method represented in the diagram.
2. Which part is ligated or cut.
3. Name the corresponding surgical method conducted in females.
4. Name the part which is ligated in females and why?

Answer:

1. Vasectomy
2. Vas deferens
3. Tubectomy
4. Fallopian tubes are ligated so that the egg may not meet with the sperms.

Question 14.
Given below is the figure of an important structure developed during pregnancy.

1. Name the structure and its type.
2. Identify ‘A’. In which technique it is used.
3. Identify ‘B’ What is its function?

Answer:
(1) The given figure is placenta. The type of placenta in humans is haemochorial placenta.

(2) A is amnio tic fluid. Amnio tic fluid is withdrawn in amniocentesis technique. From this fluid foetal cells can be obtained, which are examined for any chromosomal abnormality by karyotyping.

(3) B is umbilical cord. This is the connection between placenta of mother and growing foetus. Through the umbilical cord, foetus gets nutrition and oxygen. Nitrogenous wastes and carbon dioxide is collected from foetus and brought into maternal circulation.

Question 15.
The diagram given below is that of a intra-uterine contraceptive device. Study the same and then answer the questions that follows:

1. Give the name of intra-uterine contraceptive device shown in the diagram.
2. What is its mode of action?

Answer:

1. The Intra-uterine contraceptive device shown in the diagram is Lippes loop.
2. It is a plastic double ‘S’ loop. It attracts the macrophages stimulating them to accumulate in the uterine cavity. Macrophages increase phagocytosis of sperms within the uterus and acts as a contraceptive.

Question 16.
Identify A in the given diagram. Write the function of the same.

Answer:
A in the above diagram is intrauterine device or IUD. It is a contraceptive device inserted in the uterus of woman. This is a hormone releasing IUD. It acts as a mechanical means of contraception and avoids pregnancy.

Long answer questions

Question 1.
With the help of diagrammatic representation, explain the process of spermatogenesis.
Answer:

(1) The process of spermatogenesis takes place in the male gonads or testis. The cells of germinal epithelium that line the seminiferous tubules undergo spermatogenesis.

(2) Primordial germ cells or germinal cells pass through three phases, viz. phase of multiplication, phase of growth and phase of maturation.

• Multiplication phase : Primordial germ cells undergo mitotic divisions to produce many diploid (2n) spermatogonia.
• Growth phase : Spermatogonium accumulates nutrients and grows in size, giving rise to primary spermatocyte (2n).
• Maturation phase : The primary spermatocyte undergoes first meiotic division or maturation division. Exchange of genetic material occurs between homologous chromosomes in each spermatocyte.

(3) The meiotic division gives rise to secondary spermatocyte which is haploid (n). At the end of first meiotic division two secondary spermatocytes are formed while at the end of second meiotic division four haploid spermatids are formed.

(4) Spermatids are non-motile. They undergo spermiogenesis and form motile spermatozoan (sperm).

(5) The changes taking place during spermiogeneis are as follows:

• Increase in length.
• Formation of proximal and distal centriole.
• Distal centriole forms the axial filament.
• Mitochondria become spirally coiled.
• Acrosome is formed from Golgi complex.

Question 2.
What is oogenesis? Describe it briefly.
Answer:

1. Oogenesis is the process of formation of the haploid female gamete, i.e. ovum.

2. The process of oogenesis takes place in the follicular cells inside the ovaries. The germinal epithelium cells undergo oogenesis.

3. They pass through three phases, viz. phase of multiplication, phase of growth and phase of maturation at the time of oogenesis.

• Multiplication phase : Germinal cells undergo mitotic divisions and produce large number of diploid (2n) oogonia. Oogonia are present in the ovaries of female even before she is born.
• Growth phase : During puberty changes, the FSH from pituitary makes one oogonium to develop at a time. The growth takes place as the follicle matures and larger primary oocyte (2n) is produced inside the Graafian follicle.
• Maturation phase : The primary oocyte undergoes first meiotic division. There are equal nuclear divisions during meiosis but the cytoplasm is unequally divided.

4. By the end of first meiotic division, larger haploid secondary oocyte and smaller haploid polar body are produced. Since the embryo develops from the egg, there is provision for more food in the secondary oocyte.

(5) The second meiotic division takes place in the secondary oocyte and polar body. But this division is arrested during metaphase.

(6) The secondary oocyte is released from the ovary in the process of ovulation. Remaining division takes place if and only if ovum is fertilized.

(7) The division is unequal and form functional female gamete or ovum at the time of fertilization.

Question 3.
What is gastrulation? What are the changes that are brought about by gastrulation?
Answer:
(1) Gastrulation : The process of formation of three germ layers by morphogenetic movements and rearrangements of the cells in blastula leading to the formation of gastrula is known as gastrulation.

(2) Cells on the free end of inner cell mass called hypoblasts (primitive endoderm) become flat, divide and grow towards the blastocoel to form endoderm.

(3) Endodermal cells grow within the blastocoel to form a Yolk sac.

(4) The remaining cell of the inner cell mass, in contact with cells of Rauber are called epiblasts (primary ectoderm) which further differentiate to form ectoderm.

(5) Cells of ectoderm divide and re-divide and move in such a way that they enclose the amniotic cavity. The floor of this cavity has the embryonal disc while roof is lined by amniogenic cells. Amnion is an extra embryonic membrane that surrounds and protects the embryo.

(6) Actual gastrulation occurs about days after fertilization.

(7) Trilaminar embryonic disc begins with the formation of primitive streak and a shallow groove on the surface called primitive groove. From the site of primitive streak, a third layer of cells called mesoderm extends between ectoderm and endoderm. Anterior end of the primitive groove communicates with yolk sac by an aperture called blastopore (future anus).

(8) The embryonal knob thus finally differentiate into three layers – ectoderm, mesoderm and endoderm.

Question 4.
Explain the major changes taking place during the three trimesters of pregnancy in woman.
Answer:
The pregnancy period of approximately nine months (280 days) is divided into three trimesters of three months each.
1. First Trimester : (From fertilization to 12th week)

• During first trimester there are radical changes in the body of mother as well as in the embryo.
• The embryo receives nutrients in the first 2-4 weeks directly from the endometrium.
• It is the main period of organogenesis and the development of body organs.
• By the end of eight weeks, the major structures found in the adult are formed in the embryo in a rudimentary form. It is now called foetus and is about 3 cm long.
• Arms, hands, fingers, feet, toes, CNS, excretory and circulatory system including heart are formed and begins to work.
• Progesterone level becomes high and menstrual cycle is suspended till the end of pregnancy.
• At the end of first trimester foetus is about 7-10 cm long.
• The maternal part of placenta grows, the uterus becomes larger. In this period, the mother experiences morning sickness, (nausea, vomiting, mood swings, etc.)

2. Second Trimester: (From 13th to 26th week)

• The foetus is very active and grows to about 30 cm.
• The uterus grows enough for the pregnancy to become obvious.
• Hormone levels stabilize as hCG declines, the corpus luteum deteriorates and the placenta completely takes over the production of progesterone which maintains the pregnancy.
• Head has hair, eyebrows and eyelashes appear, pinnae are distinct. Baby’s movement can be easily felt by the mother.
• The baby reaches half the size of a new born.

3. Third Trimester: (From 27th week till the parturition)

• Foetus grows to about 50 cm in length and about 3-4 kg in weight.
• As the foetus grows, the uterus expands around it, the mother’s abdominal organs become compressed and displaced, leading to frequent urination, digestive blockages and strain in the back muscles.
• At the end of third trimester the foetus becomes fully developed and ready for parturition.

Balbharti Maharashtra State Board 11th Biology Important Questions 14 Human Nutrition Important Questions and Answers.

Maharashtra State Board 11th Biology Important Questions Chapter 14 Human Nutrition

Question 1.
Explain various steps involved in nutrition.
Answer:
The various steps involved in nutrition are as follows:

1. Ingestion: It is the introduction of food into mouth, i.e. intake of food (eating) inside the body.
2. Digestion: The process during which the complex, non-diffusible and non-absorbable food substances are converted into simple, diffusible and absorbable substances by the action of enzymes is called digestion.
3. Absorption: The process of diffusion of digested food into blood and lymph is called absorption.
4. Assimilation: The process by which protoplasm is synthesized into each cell of the body by utilizing simple food substances are called assimilation.
5. Egestion: The elimination of undigested food from the body is called egestion.

Question 2.
What are the dietary needs of human being?
Answer:
Carbohydrates, proteins, fats, vitamins, minerals, water and fibres in adequate amount are the dietary needs of human being.

Question 3.
Fill in the blanks:
i. Food provides _________ for growth and tissue repair.
ii. ________ are also required in small quantities for nutrition.
Answer:
i. energy, organic material.
ii. Vitamins, minerals.

Question 4.
Define: Digestion
Answer:
Digestion is defined as the process by which the complex, non-diffusible and non-absorbable food substances are converted into simple, diffusible and assimilable substances.

Question 5.
What is dentition?
Answer:
The study of teeth with respect to their number, arrangement, development etc. is known as dentition.

Question 6.
Describe the structure and functions of the various parts of the alimentary canal.
Answer:
Human Digestive system:
Human digestive system consists of alimentary canal and associated digestive glands.
Alimentary canal:
Alimentary canal is a long tube-like structure of varying diameter starting from mouth and ending with anus. It is about 8-10m long.
Alimentary canal consists of mouth, buccal cavity, pharynx, oesophagus, stomach, small intestine, large intestine and anus.
Mouth:

• It is also called oral or buccal cavity and is bounded by fleshy lips.
• Its side walls are formed of cheeks, roof is formed by palate and floor by tongue.
• It is internally lined by a mucous membrane.
• Salivary glands open into the buccal cavity.

Function: It helps in ingestion of food.

Teeth:

• 32 teeth are present in the buccal cavity of an adult human being.
• Human dentition is described as thecodont, diphyodont and heterodont.
• It is called thecodont type because each tooth is fixed in a separate socket present in jaw bones by gomphosis type of joint.
• In our life time, we get only two sets of teeth, milk teeth and permanent teeth. This is called diphyodont dentition.
• We have four different type of teeth hence we are heterodont.
• Types of teeth are incisors (I) canines (C) premolars (PM) and molar (M).
• Each half of each jaw has two incisors, one canine, two premolars and three molars.
• Thus, dental formula of adult human can be represented as:
  i\(\frac{2}{2}\), c\(\frac{1}{1}\), pm\(\frac{2}{2}\), m\(\frac{3}{3}\) = \(\frac{8}{8}\) = 16 × 2 = 32

Tongue:
It is the muscular fleshy organ and is roughly triangular in shape. It lies along the floor of the buccal cavity.

Functions: The upper surface of the tongue bears numerous projections called papillae.
These papillae contain sensory receptors called taste buds.

ii. Pliary nx:

• The buccal cavity leads to a short pharynx.
• Pharynx is a common passage for food and air.
• The pharynx opens into trachea through an opening called glottis.
• The glottis is guarded by a cartilaginous flap called epiglottis. The epiglottis closes during the swallowing (deglutition) action and pre vents entry of food into the trachea.
• The lower region of pharynx is called oropharynx.
• Oropharynx opens into oesophagus through gullet.

iii. Oesophagus:

• The oesophagus is a thin, muscular tube.
• It lies behind the trachea.
• It is approximately 25cm long tube passes through the neck, central aspect of rib cage, pierces the diaphragm and joins the stomach.
• It is lined by mucus cells.
• Mucus lubricates the passageway of food.
• Oesophagus is made up of longitudinal and circular muscles.

Function: The rhythmic wave of contraction and relaxation of these muscles is called peristalsis that helps in passage of food through oesophagus.

iv. Stomach:
The stomach is located in the upper left portion of the abdominal cavity.
It is a muscular sac-like ‘J1 shaped organ, around 25 to 30cm in length.
It is divided into upper cardiac region and lower pyloric region.

• Cardia or Cardiac: It is first part in which oesophagus opens. The cardia surrounds the band of circular muscles present at the junction of oesophagus and stomach called cardiac sphincter. The cardiac sphincter prevents back flow or regurgitation of food from stomach to oesophagus.
• Fundus: It is the dome shaped region above and left of cardia.
• Body: It forms the large central portion of stomach that stores the food.
• Pylorus: It is a narrow posterior region of stomach.
  It opens into duodenum, the initial part of small intestine.
  This opening is guarded by a set of sphincter muscles called pyloric sphincter.
  It regulates the flow of food from stomach to small intestine.

Function: The stomach temporarily stores the food.
It chums the food and helps in mixing the food with gastric juice.

v. Small Intestine:

• It is about 6 meters long and 2.5 cm broad tube coiled within abdominal cavity.
• The coils are held together by mesenteries, supporting the blood vessels, lymph vessels and nerves.
• It is divided into three parts: Duodenum, jejunum and ileum.

vi. Large Intestine:

• It is 1.5 meters in length.
• It is wider in diameter and shorter than small intestine.
• It consists of caecum, colon and rectum.

vii. Anus:

• Anus is the terminal opening of alimentary canal.
• It is guarded by sphincter.

Function: It expels faecal matter by a process called egestion or defecation.

Question 7.
Draw a neat and labelled diagram of stomach and write a short note on it.
Answer:
Stomach:
The stomach is located in the upper left portion of the abdominal cavity.
It is a muscular sac-like ‘J1 shaped organ, around 25 to 30cm in length.
It is divided into upper cardiac region and lower pyloric region.

1. Cardia or Cardiac: It is first part in which oesophagus opens. The cardia surrounds the band of circular muscles present at the junction of oesophagus and stomach called cardiac sphincter. The cardiac sphincter prevents back flow or regurgitation of food from stomach to oesophagus.
2. Fundus: It is the dome shaped region above and left of cardia.
3. Body: It forms the large central portion of stomach that stores the food.
4. Pylorus: It is a narrow posterior region of stomach.
   It opens into duodenum, the initial part of small intestine.
   This opening is guarded by a set of sphincter muscles called pyloric sphincter.
   It regulates the flow of food from stomach to small intestine.

Function: The stomach temporarily stores the food.
It chums the food and helps in mixing the food with gastric juice.

Question 8.
Describe the structure of Small Intestine.
Answer:
It is about 6 meters long and 2.5 cm broad tube coiled within abdominal cavity.
The coils are held together by mesenteries, supporting the blood vessels, lymph vessels and nerves.
It is divided into three parts.

1. Duodenum:
   • It is about 26 cm long ‘U’ shaped structure.
   • The duodenum turns towards left side of abdominal cavity below the stomach.
2. Jejunum:
   • It is about 2.5 meters long, coiled middle portion of small intestine.
   • It is narrower than the duodenum.
3. Ileum:
   • It is about 3.5 meters long.
   • It is highly coiled and little broader than jejunum.
   • The ileum opens into the caecum of large intestine at ileocaecal junction.

Question 9.
Explain anatomy of different parts of Large Intestine.
Answer:
Ileum opens into large intestine.
It is 1.5 meters in length.
It is wider in diameter and shorter than small intestine.
It consists of caecum, colon and rectum.

1. Caecum:
   • Caecum is a small, blind sac present at the junction of ileum and colon.
   • It is 6cm in length.
   • It hosts some symbiotic microorganisms.
   • An elongated worm like vermiform appendix arises from the caecum.
   • Appendix is vestigial organ in human beings and functional in herbivorous animals for the digestion of cellulose.
2. Colon:
   • Caecum opens into colon.
   • Colon is tube like-organ consist of three parts, ascending colon, transverse colon and descending colon.
   • The colon is internally lined by mucosal cells.
3. Rectum:
   • It is posterior region of large intestine.
   • It temporarily stores the undigested waste material called faeces till it is egested out through anus.

Question 10.
Differentiate between Small Intestine and Large Intestine
Answer:

	Small Intestine	Large Intestine
i.	It is about 6 meters long.	It is about 1.5 meters long.
ii	Small intestine is 2.5 cm broad tube.	Large intestine is broader than the small intestine. !
iii.	It is divided into three parts, as Duodenum, Jejunum, Ileum.	It is divided into three parts as – caecum, colon I and rectum.
iv	Absorbs the digested nutrients.	Takes part in absorption of water and minerals.
V.	Villi present.	Villi absent.
vi.	Digestion is completed in small intestine.	No role in digestion.

Question 11.
Explain in detail the layers of gastrointestinal tract.
Answer:
The entire gastrointestinal tract is lined by four basic layers from inside to outside namely, mucosa, submucosa, muscularis and serosa.
These layers show modification depending on the location and function of the organ concerned.

1. Serosa:
   • It is the outermost layer.
   • It is made up of a layer of squamous epithelium called mesothelium and inner layer of connective tissue.
2. Muscularis:
   • This layer is formed of smooth muscles.
   • These muscles are usually arranged in three concentric layers.
   • Outermost layer shows longitudinal muscles, middle circular muscles and inner oblique muscles.
   • This layer is wider in stomach and comparatively thin in intestinal region.
   • The layer of oblique muscles is absent in the intestine.
3. Submucosa:
   • It is formed of loose connective tissue containing blood vessels, lymph vessels and nerves.
   • Duodenal submucosa shows presence of glands.
4. Mucosa:
   • The lumen of the alimentary canal is lined by mucosa.
   • Throughout the length of alimentary canal, the mucosa layer shows presence of goblet cells that secrete mucus.
   • This lubricates the lumen of alimentary canal.
   • This layer shows modification in different regions of alimentary canal. In stomach, it is thrown into irregular folds called rugae.
   • In stomach mucosa layer forms gastric glands that secrete gastric juice.

Question 12.
Write a short note on villi.
Answer:

1. Mucosa of small intestine forms finger like folding called villi.
2. The intestinal villi are lined by brush border or epithelial cells having microvilli at the free surface.
3. Villi are supplied with a network of capillaries and lymph vessels called lacteals.
4. Mucosa forms crypis in bctween the bases of vifli in intestine called crvpís of Licberkuhn which arc intestinal glands.

Question 13.
Describe the various digestive glands associated with alimentary canal.
Answer:
The digestive glands associated with the alimentary canal include the salivary glands, liver and pancreas.

1. Salivary Glands:
   • There are three pairs of salivary glands which open in buccal cavity.
   • Parotid glands are present in front of the ear.
   • The submandibular glands are present below the lower jaw.
   • The glands present below the tongue are called sublingual.
   • Salivary glands are made up of two types of cells.
   • Serous cells secrete a fluid containing digestive enzyme called salivary amylase.
   • Mucous cells produce mucus that lubricates food and helps swallowing.
2. Liver:
   • Liver is dark reddish-brown coloured largest gland of the body, weighing 1.2 to 1.5 kg, in adults.
   • Situated in right upper portion of the abdominal cavity, below the diaphragm.
   • Divided into 2 lobes, right and left.
   • A thin connective tissue sheath called Glisson’s capsule covers the liver and invaginates inside to divide the liver into cord like structures called hepatic lobules which are functional units of liver containing hepatic cells (hepatocytes).
   • Each hepatic lobule is polygonal in shape. At the junction of adjacent lobules, a triangular portal area is present.
   • In this portal area a branch of each of hepatic artery, hepatic portal vein and bile duct are present. Lobule consist of cords of hepatic cells which are arranged around a central vein.
   • In between the cords of hepatic cells, spaces called sinusoids are present through which the blood flows. In the sinusoids, phagocytic cells called Kupffer cells are present.
   • Hepatic cells secrete bile. Bile is carried by hepatic ducts in a thin muscular sac called gall bladder.
   • The duct of the gall bladder and hepatic duct together form common bile duct.
   • Liver synthesizes vitamins A, D, K and B₁₂, blood proteins.
3. Pancreas:
   • Pancreas is a leaf shaped heterocrine gland present in the gap formed by bend of duodenum under the stomach.
   • Exocrine part of pancreas is made up of acini, the acinar cells secrete alkaline pancreatic juice that contains various digestive enzymes.
   • Pancreatic juice is collected and carried to duodenum by pancreatic duct.
   • The common bile duct joins pancreatic duct to form hepato-pancreatic duct. It opens into duodenum.
   • Opening of hepato-pancreatic duct is guarded by sphincter of Oddi.
   • Endocrine part of pancreas is made up of islets of Langerhans situated between the acini.
   • It contains three types of cells a-cells which secrete glucagon, P-cells which secretes insulin and 5 cells secrete somatostatin hormone.
   • Glucagon and insulin together control the blood-sugar level.
   • Somatostatin hormone inhibits glucagon and insulin secretion.

Question 14.
Observe the diagram given below and explain the structure and functions of the gland which stores glycogen and is involved in detoxification.

Answer:
The gland which stores glycogen and helps in detoxification is liver.

1. Liver:
   • Liver is dark reddish-brown coloured largest gland of the body, weighing 1.2 to 1.5 kg, in adults.
   • Situated in right upper portion of the abdominal cavity, below the diaphragm.
   • Divided into 2 lobes, right and left.
   • A thin connective tissue sheath called Glisson’s capsule covers the liver and invaginates inside to divide the liver into cord like structures called hepatic lobules which are functional units of liver containing hepatic cells (hepatocytes).
   • Each hepatic lobule is polygonal in shape. At the junction of adjacent lobules, a triangular portal area is present.
   • In this portal area a branch of each of hepatic artery, hepatic portal vein and bile duct are present. Lobule consist of cords of hepatic cells which are arranged around a central vein.
   • In between the cords of hepatic cells, spaces called sinusoids are present through which the blood flows. In the sinusoids, phagocytic cells called Kupffer cells are present.
   • Hepatic cells secrete bile. Bile is carried by hepatic ducts in a thin muscular sac called gall bladder.
   • The duct of the gall bladder and hepatic duct together form common bile duct.
   • Liver synthesizes vitamins A, D, K and B₁₂, blood proteins.
2. Kupffer cells of liver destroy toxic substances, dead and worn-out blood cells and microorganisms.
3. Bile juice secreted by liver emulsifies fats and makes food alkaline.
4. Liver stores excess of glucose in the form of glycogen.
5. Deamination of excess amino acids to ammonia and its further conversion to urea takes place in liver.
6. Synthesis of vitamins A, D, K and B₁₂ takes place in liver.
7. It also produces blood proteins like prothrombin and fibrinogen.
8. During early development, it acts as haemopoietic organ.

Therefore, liver is a vital organ.

Question 15.
Explain heterocrine nature of pancreas with the help of histological structure.
Answer:
Pancreas:

1. Pancreas is a leaf shaped heterocrine gland present in the gap formed by bend of duodenum under the stomach.
2. Exocrine part of pancreas is made up of acini, the acinar cells secrete alkaline pancreatic juice that contains various digestive enzymes.
3. Pancreatic juice is collected and carried to duodenum by pancreatic duct.
4. The common bile duct joins pancreatic duct to form hepato-pancreatic duct. It opens into duodenum.
5. Opening of hepato-pancreatic duct is guarded by sphincter of Oddi.
6. Endocrine part of pancreas is made up of islets of Langerhans situated between the acini.
7. It contains three types of cells a-cells which secrete glucagon, P-cells which secretes insulin and 5 cells secrete somatostatin hormone.
8. Glucagon and insulin together control the blood-sugar level.
9. Somatostatin hormone inhibits glucagon and insulin secretion.
   

Question 16.
Digestion is carried out by both mechanical and chemical methods. Justify.
Answer:

1. Mechanical digestion includes various movements of alimentary canal that help chemical digestion.
2. Mastication or chewing of food by teeth, churning in stomach and peristaltic movements of gastrointestinal tract bring about mechanical digestion in human body.
3. Chemical digestion is a series of catabolic (breaking down) reactions that hydrolyze the food.
   Thus, Digestion is carried out by both mechanical and chemical methods.

Question 17.
Write a short note on digestion in the mouth.
Answer:
Digestion in the mouth (buccal cavity):

1. Both mechanical and chemical digestion processes take place in mouth.
2. Mastication or chewing of food takes place with the help of teeth and tongue.
3. Teeth crush and grind the food while tongue manipulates the food.
4. Crushing of food becomes easier when it gets moistened by saliva.
5. Mucus in the saliva lubricates the food as well as it helps in binding the food particles into a mass of called bolus which is swallowed by deglutition.
6. The tongue presses against the palate and pushes the bolus into pharynx which further passes oesophagus.
7. The only chemical digestion that takes place in mouth is by the action of salivary amylase.
8. It helps in conversion of starch into maltose. About 30% starch gets converted to maltose in mouth.
9. The bolus further passes down through oesophagus by peristalsis.
10. Food from the oesophagus enters the stomach.
    

Question 18.
Name all the constituents of saliva.
Answer:
Saliva contains 98% water and 2% other constituents like electrolytes (sodium, potassium, calcium, chloride, bicarbonates), digestive enzyme, salivary amylase and lysozyme.

Question 19.
Which sphincter controls the passage of food into stomach?
Answer:
The gastro-oesophageal sphincter controls the passage of food into the stomach.

Question 20.
Explain the process of digestion taking place in muscular-sac like ‘J’ shaped organ.
Answer:
The muscular-sac like ‘J’ shaped organ is stomach.

1. Both mechanical and chemical digestion takes place in stomach.
2. The stomach stores the food for 4-5 hours.
3. The physical digestion take place by churning of food which done by thick muscular wall of stomach.
4. Churning further breaks down the food particles and also helps in thorough mixing of gastric juice with food.
5. The mucosa layer of stomach has gastric gland which shows presence of three major types of cells namely, mucus cells, peptic or chief cells and parietal or oxyntic cells.
6. Mucus cells secrete mucus; peptic or chief cells secrete proenzyme pepsinogen and parietal cells secrete HCl and intrinsic factor which is essential for absorption of vitamin B12. Thus, gastric juice contains mucus, inactive enzyme pepsinogen, HCl and intrinsic factor.
7. Mucus protects the inner lining of stomach from HCl present in gastric juice.
8. HCl in gastric juice makes the food acidic and stops the action of salivary amylase, and also kills the germs
   that might be present in the food.
9. Pepsinogen gets converted into active enzyme pepsin in the acidic medium provided by HCl.
10. In presence of pepsin, proteins in the food get converted into simpler forms like peptones and proteoses.
11. At the end of gastric digestion, food is converted to a semifluid acidic mass of partially digested food is
    called chyme.
12. The chyme from stomach is pushed in the small intestine through pyloric sphincter for further digestion.
    

Question 21.
What is the role of rennin in infants?
Answer:

1. Rennin found in gastric juice of infants acts on casein, a protein present in milk.
2. It brings about curdling of milk proteins with the help of calcium.
3. The coagulated milk protein is further digested with the help of pepsin.
4. Rennin is absent in adults.

Question 22.
Describe the process of digestion in small intestine.
Answer:

1. In the small intestine, intestinal juice, bile juice and pancreatic juice are mixed with food. Peristaltic movements of muscularis layer help in proper mixing of digestive juices with chyme.
2. Bile juice and pancreatic juice are poured in duodenum through hepato-pancreatic duct.
3. Bile salts present in the bile juice neutralize the acidic chyme and make it alkaline. II brings about emulsification of fats.
4. Pancreatic juices are secreted by pancreas whereas the intestinal mucosa secretes digestive enzymes. The goblet cells produce mucus.
5. The intestinal juice contains various enzymes like dipeptidases, lipases, disaccharidases, maltase, sucrase and lactase.
6. Both pancreatic and intestinal lipases initially convert fats into fatty acid and diglycerides.
7. Diglycerides are further converted to monoglycerides by removal of fatty acid from glycerol.
8. The mucus and bicarbonates present in pancreatic juice protect the intestinal mucosa and provide alkaline medium for enzymatic action.
9. Sub-mucosal Brunner’s glands help in the action of goblet cells.
10. Most of the digestion gets over in small intestine.

Question 23.
Write a short note on bile.
Answer:

1. Bile juice is dark green coloured fluid that contains bile pigments (bilirubin and biliverdin), bile salts (Na- glycocholate and Na-taurocholate), cholesterol and phospholipid.
2. Bile does not contain any digestive enzyme.
3. Bile salts neutralise the acidity of chyme and make it alkaline.
4. It brings about emulsification of fats.
5. It also activates lipid digesting enzymes or lipases.
6. Bile pigments impart colour to faecal matter.

Question 24.
What are the constituents of pancreatic juice?
Answer:

• Pancreatic juice secreted by pancreas contains pancreatic amylases, lipases and inactive enzymes trypsinogen and chymotrypsinogen.
• Pancreatic juice also contains nucleases- the enzymes that digest nucleic acids.

Question 25.
List the constituents of intestinal juice.
Answer:
The intestinal juice contains various enzymes like dipeptidases, lipases, disaccharidases, maltase, sucrase and lactase.

Question 26.
Fill in the blanks:
i. The ________ of mucosa produce mucus.
ii. Mucus plus intestinal enzymes together constitute intestinal juice or ________.
iii. Bile juice and pancreatic juice are poured in duodenum through _________ duct.
Answer:
i. goblet cells.
ii. Succus entericus.
iii. hepato-pancreatic.

Question 27.
Give the significance of peristaltic movement of muscularis in small intestine.
Answer:
Peristaltic movements of muscularis layer help in proper mixing of digestive juices with chyme.

Question 28.
Name the juices which are mixed with food in small intestines.
Answer:
Intestinal juice, bile juice and pancreatic juice.

Question 29.
Write a note on hunger hormone.
Answer:
i. Hunger hormone is also called Ghrelin.
ii. It is hormone that is produced mainly by the stomach and small intestine, pancreas and brain.
iii. It stimulates appetite, increases food intake and promotes fat storage.

Question 30.
Explain in detail the action of pancreatic juice.
Answer:

Question 31.
Explain the role of large intestine in digestion process.
Answer:

1. Conversion of proteins into amino acids, fats to fatty acids and monoglycerides, nucleic acids to sugar and nitrogenous base and carbohydrates to monosaccharides marks the end of digestion of food.
2. Food is now called chyle. Chyle is an alkaline slurry which contains various nutrients ready for absorption.
3. The nutrients are absorbed and undigested remains are transported to large intestine.
4. Mucosa of large intestine produces mucus but no enzymes.
5. Some carbohydrates and proteins do enter the large intestine.
6. These are digested by the action of bacteria that live in the large intestine.
7. Carbohydrates are fermented by bacterial action and hydrogen, carbon dioxide and methane gas are produced in colon.
8. Protein digestion in large intestine ends up into production of substances like indole, skatole and H2S.
9. These are the reason for the odour of faeces. These bacteria synthesize several vitamins like B vitamins and vitamin K.

Question 32.
What causes pancreatitis?
Answer:

1. Pancreatitis is inflammation of the pancreas.
2. It may occur due to alcoholism and chronic gallstones.
3. Other reasons include high levels of calcium, fats in blood.
4. However, in 70% of people with pancreatitis, main reason is alcoholism.

Question 33.
Match the following:

	Column I	Column II
i.	Cardiac Sphincter Pyloric	a. Regulates the flow of food from stomach to small intestine.
ii.	sphincter	b. Controls the passage of food from oesophagus into the stomach.
iii.	Gastro-oesophageal sphincter	c. Prevents back flow of food from stomach to oesophagus.

Answer:
(i – c)
(ii – a)
(iii – b)

Question 34.
Identify ‘X’, ‘Y’ and ‘Z’ in the given diarani and explain the regulation of gastric function.

Answer:

1. ‘X’- Vagus nerve, ‘Y’- Gastrin ‘Z’- Sympathetic nerve
2. Intestinal mucosa produces hormones like secretin, cholecystokinin (CCK) and gastric inhibiting peptide (G1P).
3. Secretin inhibits secretion of gastric juice.
4. It stimulates secretion of bile juice from liver, pancreatic juice and intestinal juice.
5. CCK brings about similar action and induces satiety that is feeling of fullness or satisfaction.
6. GIP also inhibits gastric secretion.

Question 35.
What is absorption? Mention the absorption of nutrients and other substances in alimentary canal?
Answer:
The passage of end products of digestion through the mucosal lining of alimentary canal into blood and lymph is called absorption. 90% of absorption takes place in small intestine and the rest in mouth, stomach and large intestine.

1. Month: Absorption takes place through mucosa of mouth and lower side of tongue into the blood capillaries, e.g. Some drugs like certain painkillers.
2. Stomach: Gastric mucosa is impermeable to most substances hence nutrients reach unabsorbed till small intestine. Little water, electrolytes, alcohol and drugs like aspirin get absorbed in stomach.
3. Small Intestine: Glucose, fructose, galactose, amino acids, minerals and water-soluble vitamins are absorbed in blood capillaries in villi. Lipids and fat-soluble vitamins ( A, D, E, K) are absorbed in lacteals.
4. Large Intestine: Absorption of water, electrolytes like sodium and chloride, drugs and some vitamins take place.

Question 36.
Name the various ways by which absorption takes place.
Ans
Simple diffusion, osmosis, facilitated transport and active transport.

Question 37.
Write the various mechanisms of absorption of compounds.
Answer:

1. Absorption of part of glucose, amino acids and some electrolytes like chloride ions are absorbed by simple diffusion depending on concentration gradient.
2. Some amino acids as well as substances like fructose are absorbed by facilitated transport.
3. In this method, carrier ions like Na+ bring about absorption.
4. Some ions are absorbed against concentration gradient. It requires energy. This type of absorption of mineral like sodium is called active transport.
5. Water is absorbed along the concentration gradient.
   [Note: Glucose and galactose are transported into absorptive cells of the villi through secondary active transport that is coupled to the active transport ofNa . Amino acids are transported via active transport.]

Question 38.
Write the transportation mechanism for monoglycerides and fatty acids.
Answer:

1. Monoglycerides and fatty acids cannot be absorbed in blood.
2. These dissolve in the centre of spherical aggregates fonned by bile salts called micelles.
3. Micelles enter into intestinal villi where they are reformed into chylomicrons.
4. Chylomicrons are small protein coated fat globules.
5. They are transported into lymph vessels called lacteals.
6. From here, they are transported to blood stream.

Question 39.
Observe the chart given on textbook page no. 169 to find out absorption in various parts of alimentary canal.
Answer:
The passage of end products of digestion through the mucosal lining of alimentary canal into blood and lymph is called absorption. 90% of absorption takes place in small intestine and the rest in mouth, stomach and large intestine.

1. Month: Absorption takes place through mucosa of mouth and lower side of tongue into the blood capillaries, e.g. Some drugs like certain painkillers.
2. Stomach: Gastric mucosa is impermeable to most substances hence nutrients reach unabsorbed till small intestine. Little water, electrolytes, alcohol and drugs like aspirin get absorbed in stomach.
3. Small Intestine: Glucose, fructose, galactose, amino acids, minerals and water-soluble vitamins are absorbed in blood capillaries in villi. Lipids and fat-soluble vitamins ( A, D, E, K) are absorbed in lacteals.
4. Large Intestine: Absorption of water, electrolytes like sodium and chloride, drugs and some vitamins take place.

Question 40.
What is assimilation?
Answer:
The absorbed food material finally reaches the tissue and becomes a part of protoplasm. This is called as assimilation.

Question 41.
Write a short note on egestion?
Answer:

1. Undigested waste is converted to faeces in colon and reaches rectum.
2. Faeces contain water, inorganic salts, sloughed of mucosal cells, bacteria and undigested food.
3. Distension of rectum stimulates pressure sensitive receptors that initiate a neural reflex for defecation or egestion.
4. It is a voluntary process that takes place through anal opening guarded by sphincter muscles.

Question 42.
How are nutrition related disorders categorised?
Answer:

• Little extra or less of nutrition can lead to dietary’ disorder (nutrition related disorder).
• Nutrition related disorders can be categorized based on the food that an individual consumes and conditions that develop due to malfunctioning of the organ/s or glands associated with digestive system.

Question 43.
What is PEM?
Answer:
Protein Energy malnutrition (PEM):

• Protein Energy Malnutrition is caused due to inadequate intake of proteins.
• It can be associated with inadequacy of vitamins and minerals in diet.
• PEM causes disease like Kwashiorkor and Marasmus.

Question 44.
What is Marasmus? What are the symptoms and causes?
Answer:

1. Marasmus is a prolonged protein energy malnutrition (PEM) found in infants under one year of age.
2. In this disease, protein deficiency is coupled with lower total food calorific value.
3. Inadequate diet impairs physical growth and retards mental development, subcutaneous fat disappears, ribs become prominent, limbs become thin, skin becomes dry, thin and wrinkled, loss of weight, digestion and absorption of food stops due to atrophy of digestive glands. There is no oedema.

Question 45.
What are the major causes of disorders like Kwashiorkor and Marasmus?
Answer:
Major causes of disorders like Kwashiorkor and Marasmus are unavailability of nutritious food. Poverty, large family size, ill spacing of children, early termination of breast feeding and overdiluted milk arc a few causes.

Question 46.
Write a short note on:
i. Indigestion
ii. Constipation
iii. Vomiting
Answer:

1. Indigestion:
   • Overeating, inadequate enzyme secretion, spicy food, anxiety can cause discomfort and various symptoms. It is called indigestion.
   • Improperly digested food or food poisoning also can cause indigestion.
   • It leads to loss of appetite, acidity (acid reflux), heart burn, regurgitation, dyspepsia (upper abdominal pain), stomach pain.
   • Avoiding eating large meal, lying down after meal, spicy, oily, junk food, smoking, alcohol are the.preventive measures for indigestion.
2. Constipation:
   • When frequency of defaecation is reduced to less than once per week the condition is called constipation.
   • Difficulty in defaecation may result in abdominal pain distortion, rarely perforation.
   • The causes are, affected colonic mobility due to neurological dysfunction like spinal cord injury, low fibre diet, inadequate fluid intake and inactivity.
   • Roughage, sufficient fluids in diet, exercise can help improve the conditions.
3. Vomiting
   • In this condition, the stomach contents are thrown out of the mouth due to reverse peristaltic movements of gastric wall.
   • It is controlled by non-vital vomiting center of medulla.
   • It is typically associated with nauseatic feeling.

Question 47.
What is diarrhoea? What are the symptoms and causes of diarrhoea?
Answer:

• Passing loose watery stools more than three times a day is called diarrhoea. Diarrhoea can lead to dehydration.
• The symptoms of diarrhoea are blood in stool, nausea, bloating, fever depending on cause and severity of the disorder.
• The causes of diarrhoea are infection through food and water or disorders like ulcer, colitis, inflammation of intestine or irritable bowel syndrome.

Question 48.
Distinguish between Kwashiorkor and Marasnius.
Answer:

	Kwashiorkor	Marasnius
i.	It is caused due to insufficient amount of proteins.	It is caused due to deficiency of fats, proteins and carbohydrates.
ii.	Oedema, fatty liver, lethargy are symptoms.	No oedema is observed. Thinning of limb is observed.
iii.	It is observed in children between 1 to 3 years of age.	It is observed in infants under one year of age.

Apply Your Knowledge

Question 49.
A person visited a pediatrician with his one-year old child complaining about the child’s weight loss and diarrhoea. The doctor examines the child and finds that his limbs have become thin, the skin has become dry as well as thin and wrinkled but there is no oedema on the body.
From this information answer the following questions:
i. Which disease child is suffering from?
ii. What is the probable reason for the disease?
iii. What would be the remedies and diet suggested by the doctor?
Answer:

1. The child is suffering from Marasmus.
2. The probable reason for the disease is Prolonged Protein Energy Malnutrition (PEM). This may cause if mother’s milk is replaced too early with foods having low protein content and calorific value.
3. Diet with adequate proteins and proper calorific value should be given to the infants.

Question 50.
Ramesh had dinner at his favorite Chinese restaurant. His menu included salad, large plate of paneer tikka masala, tandoori roti and red wine. For dessert, he consumed dark chocolate ice-cream and a glass of milkshake. He returned home and while lying on his couch watching TV he experienced chest pain and vomiting. Ramesh was taken to hospital and he was advised to watch his diet. What was the reason for Ramesh’s illness?
Answer:
Ramesh experienced reverse spasmodic peristalsis. The contents of the stomach backed up (refluxed) into Ramesh’s oesophagus. The HCL from the stomach irritated the walls of the oesophagus that resulted in burning sensation which is commonly known as heartburn. Ramesh’s heavy meal worsened the problem. Additionally, lying down immediately after meal intensified the problem.

Multiple Choice Questions

Question 1.
The roof of buccal cavity is called
(A) lingua
(B) tongue
(C) palate
(D) maxilla
Answer:
(C) palate

Question 2.
How many canine teeth are there in a normal human adult?
(A) 2
(B) 3
(C) 4
(D) 1 or 2
Answer:
(C) 4

Question 3.
What is the human dental formula?
(A) I 2/2, C 1/1, PM 2/2, M 3/3
(B) I 3/3, C2/2, PM 1/1, M 3/3
(C) I 1/1, C 3/3, PM 2/2, M 1/1
(D) T 2/2, C 2/2,PM 2/2, M 3/3
Answer:
(A) I 2/2, C 1/1, PM 2/2, M 3/3

Question 4.
The common passage of air and food is called
(A) pharynx
(B) larynx
(C) oesophagus
(D) trachea
Answer:
(A) pharynx

Question 5.
The long, thin and narrow tube connecting pharynx to the stomach is called
(A) Stomach
(B) Alimentary canal
(C) Oesophagus
(D) Duodenum
Answer:
(C) Oesophagus

Question 6.
The length of small intestine is________ metres.
(A) 15
(B) 6
(C) 2
(D) more than 30
Answer:
(B) 6

Question 7.
Main function of rectum is
(A) absorption of water from the undigested matter
(B) digestion and absorption of fats
(C) temporary storage of undigested matters
(D) both(A) and (C)
Answer:
(C) temporary storage of undigested matters

Question 8.
Vestigial organ of human body is
(A) caecum
(B) ileum
(C) appendix
(D) rectum
Answer:
(C) appendix

Question 9.
Find the odd one out.
(A) Parotid
(B) Sub – lingual
(C) Sub – maxillary
(D) Acinar
Answer:
(D) Acinar

Question 10.
The name of salivary glands present in front of ear is
(A) parotid
(B) sub maxillary
(C) sub lingual
(D) parietal
Answer:
(A) parotid

Question 11.
The largest gland of the human body is
(A) pancreas
(B) liver
(C) salivary glands
(D) thyroid
Answer:
(B) liver

Question 12.
Emulsification of fats is done by
(A) saliva
(B) gastric juice
(C) bile
(D) intestinal juice
Answer:
(C) bile

Question 13.
Kupffer cells are found in
(A) Liver
(B) Pancreas
(C) Buccal cavity
(D) Pharynx
Answer:
(A) Liver

Question 14.
The _____ cells present in pancreas secrete somatostatin hormone.
(A) Alpha
(B) Beta
(C) Delta
(D) Omega
Answer:
(C) Delta

Question 15.
Salivary amylase brings about the digestion of
(A) proteins
(B) fats
(C) carbohydrates
(D) vitamins
Answer:
(C) carbohydrates

Question 16.
Which component of saliva acts as an antibacterial agent?
(A) Lysozyme
(B) electrolytes
(C) salivary amylase
(D) water
Answer:
(A) Lysozyme

Question 17.
The enzyme in saliva that digests starch is
(A) pepsin
(B) amylase
(C) rennin
(D) maltase
Answer:
(B) amylase

Question 18.
Gastric juice contains
(A) H₂SO₄
(B) HCl
(C) ptyalin
(D) bile
Answer:
(B) HCl

Question 19.
_______ stops the activity of salivary amylase.
(A)H₂SO₄
(B) HCl
(C) Pepsin
(D) Protease
Answer:
(B) HCl

Question 20.
Proteins are broken down into Peptones by the action of
(A) Pepsin
(B) Proteases
(C) Trypsin
(D) Peptidase
Answer:
(A) Pepsin

Question 21.
Digestion in the small intestine occurs in
(A) acidic medium
(B) alkaline medium
(C) neutral medium
(D) isotonic solution
Answer:
(B) alkaline medium

Question 22.
Acidic medium of chyme is made alkaline by
(A) succus entericus
(B) pancreatic juice
(C) bile
(D) all of these
Answer:
(C) bile

Question 23.
Succus entericus is the name given to
(A) a junction between ileum and large intestine
(B) intestinal juice
(C) swelling in the gut
(D) appendix
Answer:
(B) intestinal juice

Question 24.
Protein deficiency in children causes
(A) kwashiorkor
(B) gigantism
(C) dwarfism
(D) jaundice
Answer:
(A) kwashiorkor

Question 25.
Protruding belly is a characteristic symptom of
(A) Marasmus
(B) Diarrhoea
(C) Jaundice
(D) Kwashiorkor
Answer:
(D) Kwashiorkor

Question 26.
PEM can cause disease like
(A) Marasmus
(B) jaundice
(C) diarrhea
(D) constipation
Answer:
(A) Marasmus

Question 27.
Among the following, which is a symptom of constipation?
(A) Loose motion
(B) Difficulty in defecation
(C) Vomiting
(D) Yellowing of eyes
Answer:
(B) Difficulty in defecation

Question 28.
Jaundice is caused due to
(A) abnormal bilirubin metabolism
(B) abnormal carbohydrate metabolism
(C) abnormal lipid metabolism
(D) abnormal protein metabolism
Answer:
(A) abnormal bilirubin metabolism

Question 29.
Vomiting is caused due to
(A) peristalsis
(B) reverse epistasis
(C) reverse spasmodic peristalsis
(D) osmosis
Answer:
(C) reverse spasmodic peristalsis

Competitive Corner

Question 1.
Match the items given in column-I with those in column-II and choose the correct option: [NEET Odisha 2019]

	Column I	Column II
i.	Rennin	a. Vitamin B12
ii.	Enterokinase	b. Facilitated transport
iii.	Oxyntic cells	c. Milk proteins
iv.	Fructose	d. Trypsinogen

(A) i – c, ii – d, iii – a, iv – b
(B) i – c, ii – d, iii – b, iv – a
(C) i – d, ii – c, iii – a, iv – b
(D) i – d, ii – c, iii – b, iv – a
Hint: Rennin is an enzyme which digests milk proteins. Enterokinase enzyme helps in conversion of trypsinogen into trypsin. Fructose is transported through facilitated transport. Oxyntic cells secrete Hydrochloric acid and intrinsic factors that play significant role in absorption of vitamin B₁₂.
Answer:
(A) i – c, ii – d, iii – a, iv – b

Question 2.
Kwashiorkor disease is due to – [NEET Odisha 2019]
(A) protein deficiency not accompanied by calorie deficiency
(B) simultaneous deficiency of proteins and fats
(C) simultaneous deficiency of proteins and calories
(D) deficiency of carbohydrates
Answer:
(A) protein deficiency not accompanied by calorie deficiency

Question 3.
Match the following structures with their respective location in orgAnswer: [NEET (UG) 2019]

i.	Crypts of Lieberkuhn	P	Pancreas
ii.	Glisson’s Capsule	q.	Duodenum
iii.	Islets of Langerhans	r.	Small intestine
iv.	Brunner’s Glands	s.	Liver

Select the correct option from the following:
(A) i – r, ii – s, iii – p, iv – q
(B) i – r, ii – q, iii – p, iv – s
(C) i – r, ii – p, iii – q, iv – s
(D) i – q, ii – s, iii – p, iv – r
Answer:
(A) i – r, ii – s, iii – p, iv – q

Question 4.
Identify the cells whose secretion protects the lining of gastro – intestinal tract from various enzymes. [NEET (UG) 2019]
(A) Oxyntic cells
(B) Duodenal cells
(C) Chief cells
(D) Goblet cells
Answer:
(D) Goblet cells

Question 5.
Which of the following terms describe human dentition? [NEET (UG) 2018]
(A) Pleurodont, monophyodont, homodont
(B) Thecodont, diphyodont, heterodont
(C) Thecodont, diphyodont, homodont
(D) Pleurodont, diphyodont, heterodont
Answer:
(B) Thecodont, diphyodont, heterodont

Question 6.
Lacteals absorb _________ [MHT CET 2018]
(A) amino acids
(B) fatty acids and glycerol
(C) glucose and fructose
(D) amylose and maltose
Answer:
(B) fatty acids and glycerol

Question 7.
Following are various symptoms of marasmus except, [MHT CET 2018]
(A) oedema of lower legs and face
(B) dry, wrinkled skin
(C) extreme leanness
(D) atrophy of digestive glands
Answer:
(A) oedema of lower legs and face

Question 8.
One of the following groups of enzymes forms contents of succus entericus [MHT CET 2018]
(A) maltase, enterokinase, trypsin
(B) trypsin, pepsin, lactase
(C) nuclease, amylase, chymotrypsin
(D) sucrase, maltase, dipeptidase
Answer:
(D) sucrase, maltase, dipeptidase

Question 9.
A baby boy aged two years is admitted to play school and passes through a dental check-up. The dentist observed that the boy had twenty teeth. Which teeth were absent? [NEET (UG) 2017]
(A) Incisors
(B) Canines
(C) Pre-molars
(D) Molars
Answer:
(C) Pre-molars

Question 10.
Which of the following options best represents the enzyme composition of pancreatic juice? [NEET (UG) 2017]
(A) amylase, peptidase, trypsinogen, rennin
(B) amylase, pepsin, trypsinogen, maltase
(C) peptidase, amylase, pepsin, rennin
(D) lipase, amylase, trypsinogen, procarboxypeptidase
Answer:
(D) lipase, amylase, trypsinogen, procarboxypeptidase

Balbharti Maharashtra State Board 12th Biology Important Questions Chapter 1 Reproduction in Lower and Higher Plants Important Questions and Answers.

Maharashtra State Board 12th Biology Important Questions Chapter 1 Reproduction in Lower and Higher Plants

Multiple-choice questions

Question 1.
In grafting, the rooted plant is used as a ………………
(a) scion
(b) stock
(c) stem
(d) root
Answer:
(b) stock

Question 2.
The method of propagation by root cutting is practised in ………………
(a) Rose
(b) Bougainvillea
(c) Sansevieria
(d) Blackberry
Answer:
(d) Blackberry

Question 3.
Monothecous anther has ……………… pollen sacs.
(a) single
(b) two
(c) three
(d) four
Answer:
(b) two

Question 4.
In wall of mature anther, ……………… shows fibrous thickenings.
(a) epidermis
(b) endothecium
(c) middle layer
(d) tapetum
Answer:
(b) endothecium

Question 5.
Intine consists of ………………
(a) cellulose and pectin
(b) cellulose and chitin
(c) cellulose and starch
(d) cellulose and sporopollenin
Answer:
(a) cellulose and pectin

Question 6.
The stalk of the ovule that attaches to placenta is ……………… which is attached at to the body of ovule.
(a) chalaza, hilum
(b) hilum, funiculus
(c) funiculus, hilum
(d) micropyle, hilum
Answer:
(c) funiculus, hilum

Question 7.
……………… is multicellular structure embedded in nucellus.
(a) Micropyle
(b) Chalaza
(c) Embryo sac
(d) Endothecium
Answer:
(c) Embryo sac

Question 8.
The transfer of pollen grains from the anther to the stigma is called ………………
(a) pollination
(b) fertilization
(c) transpiration
(d) viability
Answer:
(a) pollination

Question 9.
This condition is not favourable for autogamy in flowers.
(a) Bisexuality
(b) Homogamy
(c) Cleistogamy
(d) Herkogamy
Answer:
(d) Herkogamy

Question 10.
From the following, mechanism of pollination by abiotic agent is ………………
(a) Ornithophily
(b) Anemophily
(c) Entomophily
(d) Chiropterophily
Answer:
(b) Anemophily

Question 11.
In which type of flowers, the pollen grains are ribbon like without exine?
(a) Anemophilous
(b) Epihydrophilous
(c) Hypohydrophilous
(d) Entomophilous
Answer:
(c) Hypohydrophilous

Question 12.
Which flower exhibits turn pipe mechanism of pollination?
(a) Salvia
(b) Zostera
(c) Oestrum
(d) Callistemon
Answer:
(a) Salvia

Question 13.
The phenomenon of pollen grains of other flowers germinate rapidly on stigma than the pollen grains of same flower is ………………
(a) Protoandry
(b) Protogyny
(c) Prepotency
(d) Pollination
Answer:
(c) Prepotency

Question 14.
Inhibition of germination of pollen on stigma of same flower is ………………
(a) self-sterility
(b) self-pollination
(c) self compatibility
(d) selfing
Answer:
(a) self-sterility

Question 15.
The stigma provides ……………… for germination of pollen on it.
(a) oxygen
(b) water
(c) pectin
(d) malic acid
Answer:
(b) water

Question 16.
For successful artificial hybridization, these processes are essential.
(a) Disbudding and Bagging
(b) Budding and Bagging
(c) Emasculation and Budding
(d) Emasculation and Bagging
Answer:
(d) Emasculation and Bagging

Question 17.
Continued self-pollination results in ………………
(a) Hybrid vigour
(b) Genetic variability at greater extent
(c) Inbreeding depression
(d) Introduction of desired traits
Answer:
(c) Inbreeding depression

Question 18.
Heterostyly : Primula flowers : : Herkogamy: ?
(a) Gloriosa
(b) Calotropis
(c) Thea
(d) Salvia
Answer:
(b) Calotropis

Question 19.
The substance having key role in recognition and compatibility of pollen in pollen – pistil interaction is ………………
(a) special proteins
(b) special lipids
(c) pollenkitt
(d) sucrose
Answer:
(a) special proteins

Question 20.
This is NOT a type but variation in endosperm.
(a) Cellular
(b) Helobial
(c) Nuclear
(d) Mosaic
Answer:
(d) Mosaic

Question 21.
In monocot embryo, the single cotyledon is ……………… shaped and it is called ………………
(a) oval, scutellum
(b) shield, scutellum
(c) angle, coleoptile
(d) angle, coleorhiza
Answer:
(b) shield, scutellum

Question 22.
Endospermic seed : Maize : : Non-endospermic seed : ?
(a) Castor
(b) Coconut
(c) Wheat
(d) Bean
Answer:
(d) Bean

Question 23.
The integuments of fertilized ovule form the ………………
(a) seed
(b) seed coat
(c) hilum
(d) perisperm
Answer:
(b) seed coat

Question 24.
When diploid sporophytic cell forms diploid gametophyte without meiosis, it is phenomenon of ………………
(a) apogamy
(b) apocarpy
(c) apospory
(d) apoptosis
Answer:
(c) apospory

Question 25.
Which chemical substance is responsible for fruit development by Parthenocarpy?
(a) Malic acid
(b) Sucrose
(c) Boric acid
(d) Indole acetic acid
Answer:
(d) Indole acetic acid

Question 26.
Citrus seeds : Polyembryony : : Papaya fruits : ?
(a) Diplospory
(b) Apogamy
(c) Parthenocarpy
(d) Apospory
Answer:
(c) Parthenocarpy

Question 27.
Who discovered the phenomenon of double fertilization?
(a) Noll
(b) Maheshwari
(c) Leeuwenhoek
(d) Nawaschin
Answer:
(d) Nawaschin

Question 28.
When embryo development takes place the first cell of the suspensor which is towards micropylar end functions as ………………
(a) hypophysis
(b) haustorium
(c) scutellum
(d) plumule
Answer:
(b) haustorium

Question 29.
Point out the odd one.
(a) Coleoptile
(b) Coleorhiza
(c) Scutellum
(d) Perisperm
Answer:
(d) perisperm

Question 30.
Select the plant having both chasmogamous and cleistogamous flowers.
(a) Viola
(b) Primula
(c) Thea
(d) Fritillaria
Answer:
(a) Viola

Question 31.
Identify the mismatched pair.
(a) Cellular endosperm – Balsam
(b) Nuclear endosperm – Wheat
(c) Helobial endosperm – Asphodelus
(d) Mosaic endosperm – Coconut
Answer:
(d) Mosaic endosperm – Coconut

Question 32.
Up to which stage embryo development is similar in dicots and monocots?
(a) Proembryo
(b) Quadrant
(c) Octant
(d) Heart-shaped
Answer:
(c) Octant

Question 33.
The cross pollination within the same species is also called ………………
(a) hybridization
(b) xenogamy
(c) allogamy
(d) autogamy
Answer:
(b) xenogamy

Question 34.
In a recently fertilized ovule, the haploid, diploid and triploid conditions are respectively seen in ………………
(a) endosperm, nucellus, egg
(b) egg, nucellus, endosperm
(c) antipodals, oospore, primary endosperm nucleus
(d) polar nuclei, secondary nucleus, endosperm
Answer:
(c) antipodals, oospore, primary endosperm nucleus

Question 35.
In sunflower, self-pollination is avoided by ………………
(a) protogyny
(b) unisexuality
(c) self-sterility
(d) protandry
Answer:
(d) protandry

Question 36.
A versatile anther is an adaptation for ……………… type of pollination.
(a) anemophilous
(b) entomophilous
(c) hydrophilous
(d) ornithophilous
Answer:
(a) anemophilous

Question 37.
The endosperm cells in an angiospermic plant has 18 chromosomes, the number of chromosomes in its root cells will be ………………
(a) 12
(b) 6
(c) 18
(d) 24
Answer:
(a) 12

Question 38.
In porogamy, the pollen tube enters into the ovule through ………………
(a) micropyle
(b) integuments
(c) chalaza
(d) funicle
Answer:
(a) micropyle

Question 39.
Which of the following is not floral adaptation for entomophily?
(a) Large flowers
(b) Bright coloured flowers
(c) Sweet scented flowers
(d) Small inconspicuous flowers
Answer:
(d) small inconspicuous flower

Question 40.
Pollination through water is called ………………
(a) zoophily
(b) hydrophily
(c) anemophily
(d) entomophily
Answer:
(b) hydrophily

Question 41.
The types of pollination exhibited by Vallisneria and Zea mays respectively are ………………
(a) anemophily and hydrophily
(b) entomophily and hydrophily
(c) hydrophily and anemophily
(d) hydrophily and entomophily
Answer:
(c) hydrophily and anemophily

Question 42.
The union of male gamete with the female gamete is called ………………
(a) autogamy
(b) allogamy
(c) fertilization
(d) pollination
Answer:
(c) fertilization

Question 43.
The secondary nucleus is formed by the fusion of ………………
(a) two polar nuclei
(b) three nuclei
(c) two synergids
(d) two antipodal cells
Answer:
(a) two polar nuclei

Question 44.
A group of three cells situated at the base of the embryo sac are called ………………
(a) tube
(b) generative
(c) synergid
(d) antipodal
Answer:
(d) antipodal

Question 45.
The female gametophyte in angiosperms is a ……………… nucleated structure.
(a) 3
(b) 4
(c) 5
(d) 8
Answer:
(d) 8

Question 46.
In artificial hybridization, pollen grains are pollinated by ………………
(a) wind
(b) insect
(c) birds
(d) hand
Answer:
(d) hand

Question 47.
Which of the following does not occur in the embryo sac of angiosperms?
(a) egg apparatus
(b) secondary nucleus
(c) antipodal cells
(d) raphe
Answer:
(d) raphe

Question 48.
To produce 500 pollen grains, how many microspore mother cells are required ?
(a) 500
(b) 125
(c) 250
(d) 1000
Answer:
(b) 125

Question 49.
How many meiotic divisions are required for the formation of 100 seeds ?
(a) 25
(b) 50
(c) 100
(d) 125
Answer:
(b) 50

Question 50.
During fertilization, male gametes are carried by pollen tube. This is called ………………
(a) syngamy
(b) siphonogamy
(c) mesogamy
(d) polygamy
Answer:
(b) siphonogamy

Question 51.
In bisexual flowers, maturation of gynoecium before androecium is known as ………………
(a) protandry
(b) protogyny
(c) gynandry
(d) dicliny
Answer:
(b) protogyny

Question 52.
……………… is formed in angiosperms by triple fusion.
(a) Testa
(b) Integument
(c) Endosperm
(d) Suspensor
Answer:
(c) Endosperm

Question 53.
The minimum number of meiotic divisions required to produce 120 viable seeds in pea plant is ………………
(a) 150
(b) 60
(c) 120
(d) 90
Answer:
(a) 150

Question 54.
Ornithophily is effected by ………………
(a) snails
(b) insects
(c) bats
(d) birds
Answer:
(d) birds

Question 55.
Synergids are ………………
(a) haploid
(b) triploid
(c) diploid
(d) tetraploid
Answer:
(a) haploid

Question 56.
Egg apparatus consists of ………………
(a) egg and antipodals
(b) egg and polar nuclei
(c) egg and synergids
(d) egg and secondary nucleus
Answer:
(c) egg and synergids

Question 57.
Embryo sac is ………………
(a) microgametophyte
(b) microsporangium
(c) megagame tophyte
(d) megasporangium
Answer:
(c) megagametophyte

Question 58.
If the number of chromosomes in an endosperm cell is 27, what will be the chromosome number in the definitive nucleus?
(a) 9
(b) 18
(c) 27
(d) 36
Answer:
(b) 18

Question 59.
How many meiotic divisions will be needed to produce 44 female gametophytes in angiosperms?
(a) 11
(b) 22
(c) 44
(d) 66
Answer:
(c) 44

Question 60.
Endosperm of angiosperm is ………………
(a) haploid
(b) diploid
(c) triploid
(d) tetraploid
Answer:
(c) triploid

Match the columns

Question 1.

(1) Column A (Asexual)	Column B (Examples)
(1) Spore formation	(a) Spirogyra
(2) Conidia formation	(b) Yeast
(3) Fragmentation	(c) Chlamydomonas
(4) Budding	(d) Penicillium

Answer:

(1) Column A (Asexual)	Column B (Examples)
(1) Spore formation	(c) Chlamydomonas
(2) Conidia formation	(d) Penicillium
(3) Fragmentation	(a) Spirogyra
(4) Budding	(b) Yeast

Question 2.

Column A (Artificial Vegetative Propagation)	Column B (Examples)
(1) Leaf cutting	(a) Blackberry
(2) Stem cutting	(b) Apple
(3) Grafting	(c) Bougainvillea
(4) Root cutting	(d) Sansevieria

Answer:

Column A (Artificial Vegetative Propagation)	Column B (Examples)
(1) Leaf cutting	(d) Sansevieria
(2) Stem cutting	(c) Bougainvillea
(3) Grafting	(b) Apple
(4) Root cutting	(a) Blackberry

Question 3.

Column A (Part of Anatropous ovule)	Column B (Terminology)
(1) Opening at the apex	(a) Hilum
(2) Stalk of the ovule	(b) Integument
(3) Protective covering	(c) Micropyle
(4) Place of attachment of body and stalk	(d) Funiculus

Answer:

Column A (Part of Anatropous ovule)	Column B (Terminology)
(1) Opening at the apex	(c) Micropyle
(2) Stalk of the ovule	(d) Funiculus
(3) Protective covering	(b) Integument
(4) Place of attachment of body and stalk	(a) Hilum

Question 4.

Column A (Adaptation)	Column B (Type of pollination)
(1) Sticky, spiny pollen grains non-fragrant flowers	(a) Anemophily
(2) Feathery stigma and versatile anther	(b) Chiropterophily
(3) Presence of nectar glands and sweet smell	(c) Ornithophily
(4) Dull coloured flowers with strong fragrance	(d) Entomophily

Answer:

Column A (Adaptation)	Column B (Type of pollination)
(1) Sticky, spiny pollen grains non-fragrant flowers	(c) Ornithophily
(2) Feathery stigma and versatile anther	(a) Anemophily
(3) Presence of nectar glands and sweet smell	(d) Entomophily
(4) Dull coloured flowers with strong fragrance	(b) Chiropterophily

Question 5.

Column A (Mechanism)	Column B (Type of pollination)
(1) Geitonogamy	(a) Thea
(2) Herkogamy	(b) Gloriosa
(3) Self-sterility	(c) Cucurbita
(4) Protogyny	(d) Calotropis

Answer:

Column A (Mechanism)	Column B (Type of pollination)
(1) Geitonogamy	(c) Cucurbita
(2) Herkogamy	(d) Calotropis
(3) Self-sterility	(a) Thea
(4) Protogyny	(b) Gloriosa

Question 6.

Column A	Column B
(1) Nutritive tissue of embryo	(a) Perisperm
(2) Remnants of nucellus in seed	(b) Cotyledon
(3) Nutritive tissue of developing microspores	(c) Endosperm
(4) First photosynthetic organ of embryo	(d) Tapetum

Answer:

Column A	Column B
(1) Nutritive tissue of embryo	(c) Endosperm
(2) Remnants of nucellus in seed	(a) Perisperm
(3) Nutritive tissue of developing microspores	(d) Tapetum
(4) First photosynthetic organ of embryo	(b) Cotyledon

Very short answer questions

Question 1.
What is budding in plants?
Answer:
Budding in plants is an artificial method of propagation in which a single bud is joined or grafted on the stock plant.

Question 2.
What is the function of flower?
Answer:
Flower is a specialized reproductive structure which produces haploid gametes and ensures that act of fertilization will take place.

Question 3.
Enlist the wall layers of mature anther.
Answer:
Epidermis, endothecium, middle layer and tapetum are observed from outside to inside.

Question 4.
What is the peculiarity of angiospermic gametophytes ?
Answer:
The gametophytes are reduced and develop within the flower.

Question 5.
Enlist the layers of sporoderm and their composition.
Answer:
Outer layer exine is composed of sporopollenin and inner layer intine composed of cellulose and pectin.

Question 6.
What is endosporous development of embryo sac?
Answer:
The development of female gametophyte occurs within the megaspore itself.

Question 7.
Enlist the chief agents responsible for pollination process of plants.
Answer:
Abiotic agents – wind, water and Biotic agents – insects, birds, bats.

Question 8.
Describe the characters of pollens of anemophilous flowers.
Answer:
The pollen grains are produced in large number from versatile anthers and are dry, light in weight for their easy dispersal.

Question 9.
What is hay fever?
Answer:
It is the allergic symptoms observed in people who are sensitive to pollen grains mainly of anemophilous plants.

Question 10.
Enlist the different types of pollination observed in aquatic plants.
Answer:
Aquatic plants have hypohydrophilous, epihydrophilous, anemophilous as well as entomophilous type of pollination.

Question 11.
What is the main role of pistil in pollen- pistil interaction?
Answer:
As pollen grain is deposited on stigma, pistil has the ability to recognise and accept the compatible pollen of same species for further germination.

Question 12.
What type is the endosperm of coconut?
Answer:
Coconut has free nuclear vacuolated endosperm in the centre with multicellular endosperm in the outer part.

Question 13.
What is the origin of embryos in adventive polyembryony ?
Answer:
The embryos develop from diploid cells of nucellus and integuments.

Question 14.
What is vegetative propagation ?
Answer:
The reproduction which occurs with the help of vegetative organs like root, stem, leaf or bud is called vegetative reproduction or vegetative propagation.

Question 15.
What is grafting ?
Answer:
Grafting is an artificial method of vegetative propagation in which the parts of two different plants are combined in such a way that they unite with each other and continue their growth as one plant.

Question 16.
What is triple fusion?
Answer:
The process involving the fusion of a male gamete with the diploid secondary nucleus to form a triploid primary endosperm nucleus is called triple fusion.

Question 17.
What is syngamy ?
Answer:
The fusion of male gamete with the egg or oosphere to form diploid zygote or oospore is called syngamy.

Question 18.
What are the two major modes of reproduction in angiosperms ?
Answer:
The two major modes of reproduction in angiosperms are asexual reproduction and sexual reproduction.

Question 19.
What is the main feature of asexual reproduction ?
Answer:
The main feature of asexual reproduction is that it is uniparental and the offspring produced are genetically identical to the parents.

Question 20.
What is sexual reproduction ?
Answer:
The method of reproduction which involves the formation and fusion of gametes is called sexual reproduction.

Question 21.
Name the initial cells of the male and female gametophytes.
Answer:
The haploid microspores (n) and megaspores (n) are the initial cells of the male and female gametophytes.

Question 22.
At which stage, the pollen grains are liberated in the most angiosperms ?
Answer:
The pollen grains are liberated at 2-celled stage in most angiosperms.

Question 23.
What is an anatropous ovule ?
Answer:
The ovule which has a downwardly directed micropyle is called an anatropous ovule.

Question 24.
Give the scientific term used for water pollinated flowers.
Answer:
The scientific term used for water pollinated flowers is hydrophilous.

Question 25.
Give one example each of dicot endospermic seed and non-endospermic seed.
Answer:

1. Endospermic seed : Castor
2. Non-endospermic seed : Bean.

Question 26.
What is dichogamy?
Answer:
Maturation of anther and stigma at different times is called dichogamy.

Question 27.
How is diploid condition restored in angiosperms ?
Answer:
In angiosperms, the diploid condition is restored by the fusion of two haploid gametes.

Question 28.
What is egg apparatus ?
Answer:
The egg apparatus is a three-celled structure lying at the micropylar end of the embryo sac.

Question 29.
Why are some seeds of citrus referred to as polyembryonic?
Answer:
When the seeds of citrus germinate, we notice development of multiple seedling. This is due to adventive embryos formed in the seeds in addition to zygotic embryo.

Give definition/meaning of the following terms

Question 1.
Reproduction
Answer:
Reproduction is the process by which offspring is produced which resembles the parents.

Question 2.
Clones
Answer:
Morphologically and genetically identical individuals are called clones.

Question 3.
Scion
Answer:
The part of the stem containing more than one bud which is joined onto a rooted plant.

Question 4.
Stock
Answer:
Stock is a rooted plant on which part of the stem (scion) is joined in grafting.

Question 5.
Microsporogenesis
Answer:
The process in which each microspore mother cell divides meiotically to form tetrad of haploid microspores (pollen grains).

Question 6.
Pollen viability
Answer:
It is the ability of pollen grains to germinate and develop into male gametophyte.

Question 7.
Pollination
Answer:
Pollination is the transfer of pollen grains from anther to the stigma of flower.

Question 8.
Autogamy
Answer:
Autogamy is a type of pollination in which bisexual flower is pollinated by its own pollen grains.

Question 9.
Dioecism
Answer:
Dioecism is condition in which the plant bears either male or female flower and it is also called unisexuality.

Question 10.
Double fertilization
Answer:
The process of fertilization where both the male gametes participate in the complex fertilization mechanism seen in angiosperms is called double fertilization.

Question 11.
Embryogenesis
Answer:
The process of development of zygote into an embryo is called embryogenesis.

Question 12.
Dormancy
Answer:
Structural or physiological adaptive mechanism for survival is called dormancy.

Question 13.
Polyembryony
Answer:
The condition in which there is development of more than one embryo inside the seed is called polyembryony.

Give significance / importance of the following

Question 1.
Reproduction
Answer:
Reproduction is an essential process that leads to continuation of species. It also maintains the continuity of life.

Question 2.
Asexual reproduction
Answer:
The fusion of sex cells is not involved in this process thus it results in the production of genetically identical progeny from a single parent.

Question 3.
Vegetative Reproduction/Propagation
Answer:
The plants reproduce asexually from their vegetative plant parts and thus new plants formed are genetically similar to their parents.

Question 4.
Sexual reproduction
Answer:
It involves fusion of two compatible gametes and thus it results in production of genetically dissimilar offspring. Variations are set in, which are important from point of view of survival and evolution of species.

Question 5.
Exine
Answer:
Outer thick layer of pollen grain which is made up of complex non- biodegradable sporopollenin that is resistant to chemicals.

Question 6.
Germ pores
Answer:
These are thin areas in the exine, through which developing pollen tube emerges out during pollen germination.

Question 7.
Pollen viability
Answer:
The functional viability of pollen grain to form male gametophyte. It can germinate in favourable environmental conditions of suitable temperature and humidity.

Question 8.
Synergid/Filiform apparatus
Answer:
It is present in egg apparatus of embryo sac (female gametophyte) which directs the pollen tube towards the egg cell due to chemicals secreted.

Question 9.
Pollination
Answer:
Non-motile pollen grains are transferred on stigma of flower with some external abiotic or biotic agents.

Question 10.
Autogamy/Self-pollination
Answer:
In a bisexual flower, when it is pollinated by its own pollen grain the offspring formed are genetically identical to their parents.

Question 11.
Xenogamy/Cross pollination/Outbreeding
Answer:
When cross pollination takes place then that generates genetically, varied offspring.

Question 12.
Heterostyly/Heteroanthy (Heteromorphy)
Answer:
When in some flowers; stigmas and anthers are placed at different levels then it prevents self-pollination by preventing pollens to reach the stigma.

Question 13.
Double fertilization
Answer:

1. It ensures seed formation with food storage for embryo developed from fertilized egg.
2. Diploid zygote develops into embryo which further forms a new plant.
3. Triploid PEN forms endosperm which is nutritive tissue for embryo.
4. Restoration of diploid condition by syngamy.

Question 14.
Endosperm
Answer:
It is nutritive tissue of embryo developed in post-fertilization changes which also triggers the growth of embryo in proper manner.

Question 15.
Seed formation
Answer:
Seeds are important propagating units of plant and their dispersal helps in distribution of species.

Question 16.
Fruit formation
Answer:
Nourishment to the developing seeds and protection of the immature seeds is role of fruit formation.

Question 17.
Apomixis
Answer:
When embryo(s) are formed through asexual method of reproduction without gamete formation, genetically identical plants can be produced rapidly and effectively by apomixis.

Question 18.
Parthenocarpy
Answer:
Development of fruit without the process of fertilization results in formation of seedless fruit.

Question 19.
Polyembryony
Answer:
As there is development of more than one embryo in the seed it increases the chances of survival of new plants.

Name the following

Question 1.
Condition in flower when androecium matures before that of gynoecium.
Answer:
Protandry

Question 2.
Method of asexual reproduction in sponges.
Answer:
Gemmule formation

Question 3.
Method in which small amount of plant tissue is carefully grown.
Answer:
Tissue culture.

Question 4.
Recent or Modern method of vegetative reproduction of plants form plant tissue.
Answer:
Micropropagation.

Question 5.
Most common type of ovule in angiosperms.
Answer:
Anatropous

Question 6.
A diploid nucleus in central cell of embryo sac in plants.
Answer:
Secondary nucleus or definitive nucleus

Question 7.
A condition of flowers where its sex organs are exposed.
Answer:
Chasmogamy.

Question 8.
Components necessary to induce germination of pollen in synthetic medium.
Answer:
Sucrose and boric acid.

Question 9.
The plant material in which double fertilization was discovered.
Answer:
Liliaceae plants like Lilium and Fritillaria.

Question 10.
A condition in which pollen tube enters the ovule through micropyle, through chalaza or through integuments.
Answer:
Porogamy, chalazogamy and mesogamy respectively.

Question 11.
Non-motile male gametes are carried through hollow tube when pollen grain germinate.
Answer:
Siphonogamy

Question 12.
Layers of seed coat.
Answer:
Outer testa and inner tegmen

Question 13.
A state of metabolic arrest that helps in survival of organism In adverse conditions.
Answer:
Dormancy.

Question 14.
Name the nuclei taking part in triple fusion.
Answer:
The nucleus of male gamete and the secondary nucleus formed by fusion of two polar nucleI.

Question 15.
What do you call the kernel that you eat in tender coconut?
Answer:
Coconut meat (kopra)

Distinguish between

Question 1.
Asexual Reproduction – Sexual Reproduction
Answer:

Asexual Reproduction	Sexual Reproduction
1. Fusion of sex cells or two compatible gametes is not involved.	1. Fusion of sex cells or two compatible gametes is involved.
2. It results in production of genetically identical progeny.	2. It results in production of genetically dissimilar offspring.
3. Offspring inherit genes of the parent.	3. Offspring have combination genes from both the parents through their gametes.
4. Variations are not observed in progeny.	4. Variations due to recombination are observed which are useful for survival and evolution of species.

Question 2.
Autogamy (Self-pollination) – Xenogamy (cross pollination)
Answer:

Autogamy (Self-pollination)	Xenogamy (Cross pollination)
1. In self-pollination, bisexual flower is pollinated by its own pollen grains.	1. In cross pollination the pollen grains from the anther are carried to the stigma of another flower of same species.
2. Self-pollination does not depend upon external agents for pollination.	2. Cross pollination does depend upon external agents for pollination.
3. Self-pollination is economical as there is no wastage of pollen grains.	3. Cross pollination is not economical as there is wastage of pollen grains during transfer.
4. Offspring are genetically similar to their parents; E.g. Pea	4. Offspring are genetically varied due to recombination. E.g. Food and fibre crops – Maize, Rice.

Question 3.
Hypohydrophily – Epihydrophily
Answer:

Hypohydrophily	Epihydrophily
1. Pollination takes place below the surface of water.	1. Pollination takes place on the surface of water.
2. Pollen grains are heavier and they sink in water.	2. Pollen grains float on the water surface.
3. Pollens are long, ribbon like without exine.	3. Pollens have specific gravity equal to water.
4. E.g. Zostera (sea grass)	4. E.g. Vallisneria

Give scientific reasons

Question 1.
The development of embryo sac is described as monosporic.
Answer:

1. Embryo sac develops inside the nucellus of ovule from megaspore.
2. Megaspore mother cell is diploid structure which undergoes meiosis.
3. After meiosis, tetrad of haploid cells are produced.
4. The upper three megaspores degenerate and the lower one of the tetrad is functional.
5. The entire embryo sac is developed by elongation and then three mitotic divisions of this single megaspore take place hence the development is described as monosporic.

Question 2.
Pollination is prerequisite for fertilization in plants.
Answer:

1. Fertilization is fusion of male and female gametes.
2. Pollination is transfer of pollen grains which carry non-motile male gametes.
3. Pollen grains are transferred from anther to stigma of flower where they germinate.
4. Both male and female gametes are non- motile and they are produced at two different sites.
5. Therefore the pollination process is necessary for act of fertilization in plants.

Question 3.
Dichogamy favours cross pollination.
Answer:

1. Maturation of anther (stamen) and stigma (carpel) at different times is called dichogamy.
2. Dichogamy is of two types, viz, protandry and protogyny.
3. Maturity of anthers before that of gynoecium is protandry and maturity of carpel before maturity of pollen grains is protogyny.
4. As this forms barrier for self-pollination, dichogamy favours cross pollination.

Question 4.
Fertilization in angiosperms is double fertilization.
Answer:

1. In angiosperms, pollen tube carries two non-motile male gametes.
2. Pollen tube enters the embryo sac in synergids and the contents are relased.
3. Out of the two male gametes produced by the male gametophyte, one unites with female gamete i.e syngamy and the other with the secondary nucleus i.e. triple fusion.
4. Since both the male gametes take part in fertilization which takes place twice, it is called double fertilization.

Question 5.
Castor seed is endospermic or albuminous.
Answer:

1. Endosperm, that is developed after fertilization is a nutritive tissue for developing embryo.
2. Endosperm stores food material.
3. In some seeds this reserved food is partially utilized by embryo for development, E.g; Castor.
4. The endosperm remains in the seed and it is utilized further during seed germination. Hence the seed is endospermic or albuminous.

Question 6.
Parthenocarpic fruits are without seeds.
Answer:

1. In parthenocarpy, fruit is developed without fertilization.
2. When fertilization takes place ovules in the ovary are transformed into seeds.
3. In parthenocarpy, for fruit development chemical stimulus from placental tissue transforms or stimulates ovary into fruit but it is seedless.

Question 7.
Nucellar polyembryony is significant in horticulture.
Answer:

1. Polyembryony is a phenomenon where we get many embryos in the seed.
2. Polyembryony increases chances of survival of plants as there are multiple seedlings formed.
3. Nucellar embryos are formed from diploid parental tissue.
4. Thus genetically uniform type of seedlings are obtained which are similar to parents.

Write the short notes on the following

Question 1.
Vegetative reproduction.
Answer:

1. It is asexual method of reproduction.
2. Plants reproduce through their vegetative plant parts.
3. New plants produced are genetically identical to their parents.
4. It is very useful in agriculture and horticulture.
5. Artificial methods like cutting and grafting are useful for propagation of desired varieties as per human needs.

Question 2.
Grafting.
Answer:

1. It is type of artificial vegetative propagation.
2. In this method two different plants are joined together.
3. The part of stem containing one or more buds is scion which is joined on a rooted plant stock.
4. They grow as one plant, e.g. Apple, Pear, Mango.
5. When a single bud is grafted on a stock plant it is known as bud grafting or budding, e.g. Rose.

Question 3.
Pollen Viability.
Answer:

1. It is a functional ability of pollen grain to form male gametophyte by its germination.
2. Viable pollen grains germinate on stigmatic surface,
3. Environmental factors mainly temperature and humidity influence its germination.
4. Viability is low up to 30 minutes in plants like rice and wheat.
5. Duration of viability is up to months in some plants of family Leguminosae, Rosaceae and Solanaceae.

Question 4.
Seed Dormancy.
Answer:

1. It is a state of metabolic arrest which helps in survival of organism in unfavourable environmental conditions.
2. Structure or physiological adaptive measures of seed that are helpful in adverse conditions is called dormancy.
3. Seeds are dispersed during their dormancy.
4. When dormancy period of seeds is completed then only the viable seed germinate.

Question 5.
Parthenocarpy.
Answer:

1. It is a condition in which fruit is developed without event of fertilization.
2. It is a natural process observed on Pineapple and Banana.
3. A chemical stimulus in the form of auxin (IAA) is given by placental tissues of unfertilized ovary.
4. Due to the stimulus, enlargement of ovary takes place to form a fruit.
5. Parthenocarpic fruits are without seeds.

Question 6.
Polyembryony.
Answer:

1. It is a condition when more than one embryos are developed inside the seed.
2. It was first noticed in Citrus by Leeuwenhoek.
3. When embryos develop from diploid cells of nucellus or integuments, it is described as adventive polyembryony.
4. When zygote divides into small units which develop into embryos then it is called cleavage polyembryony.
5. It results in multiple seedlings and is of significance in horticulture.

Question 7.
Anemophily.
Answer:

1. The transfer of pollen grains through wind is called anemophily.
2. Plants that are pollinated by wind are called anemophilous plants.
3. Anemophilous plants bear small and inconspicuous flowers without any bright colours, fragrance and nectar.
4. Flowers are produced in large numbers.
5. Stamens are long with versatile anthers.
6. Stigma is feathery, exposed to receive the pollen grains coming along with the wind, e.g. Grasses, maize, Jowar and Palms.

Question 8.
Hydrophily.
Answer:

1. The transfer of pollen grains with the help of water is called hydrophily.
2. Plants that are pollinated by water are called hydrophilous plants.
3. Hydrophilous plants possess small, inconspicuous unisexual flowers.
4. Flowers lack fragrance, nectar and bright colour.
5. Pollen grains and other floral parts are protected from getting wet.
6. Stigma is long and sticky, e.g. Zostera, Vallisneria, etc.

Question 9.
Omithophily.
Answer:

1. The transfer of pollen grains through birds is called ornithophily.
2. Bird pollinated plants are called ornithophilous plants.
3. Ornithophilous plants bear large and showy flowers.
4. Flowers brightly coloured to attract birds for pollination.
5. Ornithophilous flowers lack fragrance as birds have poor sense of smell.
6. Pollen grains are sticky and spiny e.g. Callistemon, Bignonia, Bombax, Butea, etc.

Question 10.
Dichogamy.
Answer:

1. When stamens and carpels mature at different times in a bisexual flower, the condition is known as dichogamy.
2. Owing to dichogamy self-pollination is avoided and cross pollination is favoured.
3. Dichogamy is of two types, viz., protandry and protogyny.
4. Protandry is seen in sunflower in which pollen grains are released much before stigma becomes receptive.
5. In protogyny, stigma becomes ready to receive the pollen grains before the anthers mature. It is seen in plants like Gloriosa.

Question 11.
Embryo sac.
Answer:

1. Egg apparatus is a three celled structure lying at the micropylar end of the embryo sac.
2. The egg apparatus consists of a median egg cell called oosphere and two lateral cells called synergids.
3. The embryo sac also consists of three antipodal cells or antipodals towards the chalazal end which degenerate after fertilization.
4. In the centre, the embryo sac consists of a large central cell consisting of two haploid polar nuclei.
5. The polar nuclei at a later stage fuse with each other forming a diploid secondary nucleus.
6. The secondary nucleus develops into endosperm.

Question 12.
Entomophily.
Answer:

1. Pollination with the help of insects is called entomophily.
2. The insect pollinated flowers are called J entomophilous flowers.
3. Entomophilous flowers show the following adaptations:
4. Flowers are large and attractive.
5. Flowers are brightly coloured with i pleasant smell.
6. Flowers produce nectar which is food for the insects.
7. Pollen grains are spiny and sticky for easy adherance to the rough and sticky stigma.
8. Entomophily is seen in plants like rose, Jasmine, Oestrum, Salvia, etc.

Question 13.
Endosperm.
Answer:

1. Endosperm is a nutritive tissue. It nourishes the developing embryo.
2. The endosperm develops from the primary endosperm nucleus (PEN).
3. The endosperm is a post fertilization tissue.
4. There are two types of seeds depending upon the presence or absence of endosperm, viz., endospermic and non-endospermic.
5. Castor, coconut, maize, etc. are endospermic seeds, while bean, pea, gram, etc. are non-endospermic seeds.

Question 14.
Triple fusion.
Answer:

1. Triple fusion is also called second fertilization.
2. Out of the two male gametes in angiosperms, the first one fuses with the egg to form the zygote, while the second one fuses with the secondary nucleus to form primary endosperm nucleus. This is called triple fusion. Since each of the polar nuclei is a sister nucleus of the egg, it is called second fertilization.
3. First fusion involves the fusion of a male gamete with the egg; the second fusion involves the fusion of two polar nuclei to form the secondary nucleus and the third fusion involves the fusion of the other male gamete with the secondary nucleus.

Short Answer Questions

Question 1.
What is asexual reperoduction? Describe fragmentation.
Answer:

1. Production of offspring without involving fusion of two compatible gametes or sex cells is called asexual reproduction.
2. Fragmentation : It is a type of asexual reproduction observed in lower plants, e.g. algae.
3. Multicellular organisms break into small pieces called fragments which develop into new plant.
4. These fragments are formed due to different reasons like accidental breakdown, death and decay of cells, etc.

Question 2.
Explain about artificial methods of vegetative reproduction.
Answer:

1. Vegetative propagation is a kind of asexual reproduction which occurs with the help of vegetative plant parts.
2. Cutting and grafting are two methods used to propagate desired varieties of plants.
3. Cutting – small pieces of plant parts having one or more buds are selected for propagation, e.g, Stem cutting – Rose, Root Cutting – Blackberry and Leaf cutting – Sansevieria.
4. Grafting – In this method two plant parts are joined ogether (Stock – rooted plant and Scion-attached plant and they continue their growth as one plant.
5. When a single bud is grafted on stock plant it is called as bud grafting, e.g. Rose, Apple, Pear.

Question 3.
What do bananas and figs have in common?
Answer:
Banana and fig, both are edible, soft, pulpy sweet fruits which are rich source of potassium. They are grown commercially.
[Note : Banana is a true fruit, simple fleshy berry, developing from single ovary. It may contain tiny seeds in pulp. Banana is parthenocarpic fruit which is developed by parthenocarpy.

Fig is a composite fruit syconus, developing from hypanthodium inflorescence. It is 5 pollinated by insect. We come across tiny seeds inside pulp. It is a false fruit. Receptacle is edible part which encloses tiny female flowers?]

Question 4.
Describe the T.S. of anther.
OR
Sketch and label the T.S. of undehisced anther.
Answer:

1. Internally it shows four chambers called microsporangia or pollen sacs.
2. The anther consists of two main parts, viz., anther wall and microsporangium or pollen sac.
3. The wall of the anther can be differentiated into four layers, viz., epidermis, endothecium, middle layers and tapetum.
4. The epidermis is the outermost layer of the anther wall. It is made up of flattened cells which are protective in function.
5. The endothecium lies internal to the epidermis. It is made up of a single layer of cells. The cells of endothecium show fibrous thickenings on radial walls.
6. Internal to the endothecium, lie 1 to 3 layers of parenchymatous cells forming middle layers of the anther wall. The cells of middle layers degenerate at maturity during the formation of microspores.
7. The tapetum is the innermost nutritive layer of the wall of the anther, consisting of a single layer of cell surrounding the sporogenous tissue.

Question 5.
Describe the structure of a mature anatropous ovule or a typical angiospermic.
Answer:

1. The ovule which has a bent axis and downwardly directed micropyle is called anatropous ovule.
   It is the most common type of ovule in angiosperms.
2. The matured anatropous ovule consists of two parts, viz., the stalk and the body. The stalk of the ovule is called the funicle or funiculus. The funicle attaches the ovule with the placenta.
3. The point at which the funicle is attached to the body of the ovule is called hilum.
4. Nucellus : It is made up of diploid parenchymatous cells.
   The basal part of the nucellus is called chalaza.
   The protective coverings of the nucellus are called integuments.
5. Micropyle : The integuments do not completely cover the nucellus. They leave a small opening called micropyle at the tip.
6. Embryo sac : In a mature ovule, the nucellus shows an oval-shaped structure towards its micropylar end called embryo sac or female gametophyte.

Question 6.
Why do some plants have both chasmogamous and cleistogemous plants flowers?
Answer:

1. When flowers open, their sex organs are exposed for further process of fertilization then it is chasmogamous condition.
2. Pollinating agents can easily transfer pollen grains in such flowers for self as well as cross pollination.
3. When flowers are closed, they are self pollinated in bud conditions then this condition is cleistogamy.
4. When some plants have both of these types of flowers it ensures pollination and fertilization leading to seed setting. When seeds are formed then perpetuation of species is achieved as new plants will germinate from it.

Question 7.
What is pollination ? What are its two types ?
Answer:
1. Pollination : The transfer of pollen grains from the anther to the stigma is called pollination.

2. Types of pollination : Pollination is of two types, viz., self-pollination and cross pollination.
(i) Self-pollination (Autogamy) : The transfer of pollen grains from the anther to the stigma of the same flower or a different flower possessing the sam genetic make-up is called self-pollination.

(ii) Cross pollination (Allogamy) : The transfer of pollen grains from the anther of a flower to the stigma of another flower borne by a different plant possessing dissimilar genetic make-up is called cross pollination.

Question 8.
What are the different types of cross pollination based on the abiotic pollinating agents?
Answer:
Based on the abiotic pollinating agents, pollination can be either anemophily or hydrophily.
(1) Anemophily : Pollination with the help of wind is called anemophily. The wind pollinated plants are called anemophilous plants. Anemophily is seen in plants like grasses, maize, wheat, rice, palms, etc.

(2) Hydrophily : Pollination effected through the agency of water is called hydrophily. Water pollinated plants are called hydrophilous plants. Hydrophily is of two types viz., hypohydrophily and epihydrophily. Plants such a zostera, Vallisneria, etc. are hydrophilous plants.

Question 9.
What are different types of cross pollination based on the biotic pollinating agents?
Answer:
Cross pollination through biotic agents are entomophily, ornithophily and chiropterophily.
(1) Entomophily : Pollination effected through insects is called entomophily. Insect pollinated plants are called entomophilous. Entomophily is seen in plants like Hibiscus, Rose, Salvia, Oestrum, Jasmine, etc.

(2) Ornithophily : Pollination effected through the agency of birds is called ornithophily. Bird pollinated plants are called ornithophilous plants.
Ornithophily is seen in plants like Callistemon, Bombax, Butea, etc.

(3) Chiropterophily : Pollination effected through bats is called chiropterophily. Bat pollinated plants are called chiropterophilous plants. Chiropterophily is seen in plants like Anthocephalous (Kadamb tree), Adansonia (Baobab tree), Kigellia (Sausage tree).

Question 10.
Give the floral adaptations for chiropterophily.
Answer:

1. The pollination that occurs with the help of bats is called chiropterophily.
2. In chiropterous plants the flowers are large and stout enough in such a way that bats can hold onto the flowers.
3. Chiropterous flowers are nocturnal, i.e., they open during the night time only.
4. Flowers emit rotten fruits like fermenting fruity odours which attract bats.
5. Flowers produce copious nectar.
6. Flowers possess large number of stamens which produce large amount of edible pollen grains.
7. Anthocephalus, Kigellia and Adansonia are chiropterous flowers.

Chart or Table based guestions

I. Complete the following charts

Question 1.

Answer:

Question 2.

Answer:

Question 3.

Answer:

II. Complete the following tables

Question 1.

Answer:

Question 2.
Complete the table-Related to outbreeding devices.

Type	Description	Example
1. ————	Unisexual flowers/Monoecious or dioecious plants	Papaya, Maize
2. ————	Mechanical device to prevent Self-Pollination – Natural physical barrier	—————-
3. Prepotency	——————–	Apple
4. Heteromorphy	——————–	Primula
5. Protandry	Androecium matures earlier than gynoecium	—————-

Answer:

Type	Description	Example
1. Unisexuality	Unisexual flowers/Monoecious or dioecious plants	Papaya, Maize
2. Herkogamy	Mechanical device to prevent Self-Pollination – Natural physical barrier	Calotropis
3. Prepotency	Pollens of other flower germinate rapidly rather than from same	Apple
4. Heteromorphy	Presence of different forms of flowers with respect to Stigma and anthers	Primula
5. Protandry	Androecium matures earlier than gynoecium	Sunflower disc florets

Question 3.

Hypohydrophily	Epihydrophily
1. Porogamy	————–
2. ————–	Entry of pollen tube in Ovule piercing integuments
3. —————	Entry of pollen tube in Ovule through Chalaza

Answer:

Hypohydrophily	Epihydrophily
1. Porogamy	Entry of pollen tube into Ovule through micropyle
2. Mesogamy	Entry of pollen tube in Ovule piercing integuments
3. Chalazogamy	Entry of pollen tube in Ovule through Chalaza

Diagram based questions

Question 1.
T. S. of anther.
Answer:

Question 2.
Development of male gametophyte
Answer:

Question 3.
Development of female gametophyte
Answer:

Question 4.
Double fertilization
Answer:

Question 5.
Maize Seed.
Answer:

Question 6.
Entry of pollen tube into Ovule – Porogamy
Answer:

Long Answer Questions

Question 1.
Describe the types of reproduction in lower plants (i) Budding and (ii) Sporulation. Illustrate your answer with suitable diagrams.
Answer:
(i) Budding:

1. It is a type of asexual reproduction.
2. It is of very common occurrence in unicellular organism yeast.
3. It is observed in favourable condition.
4. Mother cell produces small outgrowth which is known as bud.
5. Buds maybe one or more and on separation, they grow as new individual.

(ii) Spore formation/Sporulation:

1. It is a tpe of asexual reproduction.
2. It is of very common occurrence in lower plants.
3. It occurs by production of motile zoospores that are formed in sporangia.
4. Flagellated zoospores when liberated can grow independently into new individuals.
5. Biflagellate zoospores are formed in algae Chlamydomonas.

Question 2.
Describe the structure of a mature pollen grain.
OR
Sketch and label pollen grain.
Answer:

1. A typical angiospermic pollen grain (mature) is a unicellular, uninucleate, spherical or oval haploid structure.
2. The pollen grain is also called microspore.
3. It is covered and protected by a double layered wall called sporoderm.

1. The outer layer of the wall is thick. It is known as exine. The inner layer of the wall is thin. It is known as intine.
2. The exine is made up of a complex substance called sporopollenin. The sporopollenin protects the pollen grain from physical and biological decomposition.
3. The exine is spiny in insect pollinated plants, with sculptured pattern or smooth in wind pollinated plants.
4. The exine is not continuous throughout. It is interrupted, very thin at one or more places by small pores called germ pores.
5. The intine which is composed of cellulose and pectin encloses the protoplasm with a single haploid nucleus.

Question 3.
Describe the development of female gametophyte in angiosperms.
OR
What is megasporogenesis ? Give an account of development of the female gametophyte.
OR
With a neat diagram explain the 7-celled, 8-nucleate nature of the female gametophyte.
Answer:
1. Megasporogenesis : The process by which . the diploid megaspore mother cell of nucellus undergoes meiosis to form a tetrad of haploid megaspores is known as megasporogenesis.

2. Development of female gametophyte:
(i) The diploid megaspore mother cell undergoes meiosis to form a linear tetrad consisting of four-haploid megaspores. Generally, the chalazal megaspore becomes the functional megaspore. The other three megaspores degenerate.

(ii) The chalazal megaspore (fertile megaspore) is the first cell of the female gametophyte. It undergoes enlargement and develops into the female gametophyte. The haploid nucellus of chalazal megaspore undergoes three successive free nuclear mitotic divisions to produce eight nuclei. Of these, the first mitotic division results in the formation of two nuclei.

(iii) Both these nuclei undergo two successive mitotic divisions resulting in the formation of four nuclei at both the poles. In the meantime, one nucleus from each pole called polar nucleus moves towards the centre of the embryo sac and fuse to form a diploid nucleus called secondary nucleus.

(iv) The three nuclei at the micropylar end are organised to form a three-celled structure called egg apparatus, while the other three nuclei at the chalazal end reorganise to form three antipodal cells. The egg apparatus consists of a central cell called egg cell or female gamete which is flanked by two lateral cells called synergids.

(v) The female gametophyte consists of an egg apparatus, a secondary nucleus and three antipodal cells, A7 celled 8 nucleated structure.

Question 4.
What are the three types of endosperm? Describe them briefly.
Answer:
There are three types of endosperm, viz., nuclear, cellular and helobial.
(i) Nuclear endosperm:

1. Nuclear endosperm is the most common type of endosperm.
2. During the formation of nuclear endosperm, the primary endosperm nucleus (PEN) undergoes free nuclear division forming a large number of triploid nuclei which remain freely suspended in the common cytoplasm of central cell.
3. A central vacuole pushes the nuclei towards periphery.
4. Later on wall formation takes place around these nuclei to form a cellular mass.
5. It is seen in plants like maize, sunflower, wheat, coconut, etc.

(ii) Cellular endosperm:

1. In this type of endosperm, the triploid primary endosperm nucleus undergoes nuclear divisions followed by cytokinesis.
2. Owing to this, the development of endosperm occurs in cellular form.
3. It is less common and seen in dicot plants like Datura, Petunia, Balsam, Adoxa.

(iii) Helobial endosperm:

1. In helobial type of endosperm, the first division of the primary endosperm nucleus is followed by the formation of cell wall.
2. Owing to this, the central cell is divided into a large micropylar cell and a small chalazal cell.
3. In both micropylar and chalazal chamber, the further development of the endosperm is of nuclear type.
4. Walls develop between nuclei in micropylar chamber.
5. This type of embryo development is seen in plants belonging to order Helobiales of Monocots. e.g. Asphodehis.

Question 5.
What is apomixis? Explain the categories of apomixis.
Answer:
(i) Apomixis : The phenomenon of formation of embryo(s) by asexual methods without formation of gametes and fertilization is termed as apomixis.

(ii) There are three main categories of apomixis.

1. Recurrent
2. Non-recurrent and
3. Adventive embryony.

1. Recurrent apomixis : In this diploid sporophytic cell, archesporial cell or nucellus form embryos, When diploid megaspore mother cell forms embryo sac it is known as diplospory. It is also called apospory.

2. Non-recurrent apomixis : Haploid embryo sac is formed but the embryos arise either from egg cell or any other haploid cell. It is also known as apogamy.

3. Adventive Embryony : In this in addition to normal zygotic embryo, additional embryos develop from nucellus or integuments. It results in polyembryony.

Balbharti Maharashtra State Board 11th OCM Important Questions Chapter 7 Business Environment Important Questions and Answers.

Maharashtra State Board 11th Commerce OCM Important Questions Chapter 7 Business Environment

Select the correct option and rewrite the sentence

Question 1.
……………….. indicates the importance of the business environment.
(a) Identifying opportunities and threats
(b) Identifying firm’s strength and weakness
(c) both (a) and (b)
Answer:
(c) both (a) and (b)

Question 2.
……………….. is an example of the social environment.
(a) Gross Domestic Product
(b) Consumer Protection, Act
(c) Customs and beliefs
Answer:
(c) Customs and beliefs

Question 3.
Liberalisation means ………………..
(a) reduced government controls and restrictions
(b) integration of economies
(c) policy of planned disinvestment
Answer:
(a) reduced government controls and restrictions

Question 4.
……………….. explains the impact of Government policy changes on business and industry.
(a) More demanding customers
(b) License system
(c) More industries for public sector
Answer:
(a) More demanding customers

Question 5.
……………….. environment consist of the methods and techniques adopted for production.
(a) Legal
(b) Political
(c) Technological
Answer:
(c) Technological

Question 6.
The policies decided by shareholders, managers, labour unions and the employees are known as ………………..
(a) Internal environment factors
(b) External environment factors
(c) International factors
Answer:
(a) Internal environment factors

Question 7.
……………….. is very powerful because powers such as policy making, law making, budget approving, etc. are in its hands.
(a) Government
(b) Judiciary
(c) Legislature
Answer:
(c) Legislature

Question 8.
……………….. economy is known as free market economy.
(a) Socialist
(b) Capitalist
(c) Mixed
Answer:
(b) Capitalist

Question 9.
……………….. does not involve an equal division of existing wealth among the people.
(a) Capitalist Economy
(b) Socialist Economy
(c) Mixed Economy
Answer:
(b) Socialist Economy

Question 10.
Globalisation includes ………………..
(a) Minimising high import tariffs
(b) Introduction of selective competition in the reserved area
(c) Reduction in physical restrictions on import and import duties.
Answer:
(a) Minimising high import tariffs

Question 11.
Changes in the fiscal policy of the Government is an aspect of ……………….. environment.
(a) Political
(b) Social
(c) Economic
Answer:
(c) Economic

Question 12.
Changes in the judicial system is an aspect of ……………….. environment.
(a) Economic
(b) Social
(c) Legal
Answer:
(c) Legal

Question 13.
Privatisation implies reduction in the role of ……………….. sector.
(a) Public
(b) Private
(c) Joint
Answer:
(a) Public

Question 14.
Level of literacy is an aspect of ……………….. environment.
(a) Economic
(b) Social
(c) Political
Answer:
(b) Social

Question 15.
Changes in the ruling government is an aspect of ……………….. environment.
(a) Economic
(b) Social
(c) Political
Answer:
(c) Political

Match the pairs

Question 1.

Part A	Part B
(a) Globalisation	(1) Reduced role of Public sector
(b) Privatisation	(2) Digital India
(c) Liberalisation	(3) Competition Act, 2002
(d) Technological Environment	(4) Mining of coal
(e) Natural Environment	(5) Integration of world economies
	(6) Increased role of public sector
	(7) Exercising controls
	(8) Occupation of people
	(9) Differentiation of economies
	(10) Removing unnecessary controls

Answer:

Part A	Part B
(a) Globalisation	(5) Integration of world economies
(b) Privatisation	(1) Reduced role of Public sector
(c) Liberalisation	(10) Removing unnecessary controls
(d) Technological Environment	(2) Digital India
(e) Natural Environment	(4) Mining of coal

Question 2.

Part A	Part B
(a) Internal Environment	(1) Stability and peace in the country
(b) Social Environment	(2) Value System
(c) Political Environment	(3) Monetary Policy
(d) Economic Environment	(4) Indian Contract Act, 1872 (2017)
(e) Legal Environment	(5) Customs and Traditions
	(6) Digital India

Answer:

Part A	Part B
(a) Internal Environment	(2) Value System
(b) Social Environment	(5) Customs and Traditions
(c) Political Environment	(1) Stability and peace in the country
(d) Economic Environment	(3) Monetary Policy
(e) Legal Environment	(4) Indian Contract Act, 1872 (2017)

Question 3.

Part A	Part B
(a) Privatisation	(1) Management
(b) Internal Environment	(2) National economy
(c) Liberalisation	(3) Values and demographic trends
(d) Political Environment	(4) Disinvestment
(e) Globalisation	(5) Delicensing
(f) Legal Environment	(6) World Economy
(g) Social Environment	(7) National Income Distribution
(h) Economic Environment	(8) Judicial System

Answer:

Part A	Part B
(a) Privatisation	(4) Disinvestment
(b) Internal Environment	(1) Management
(c) Liberalisation	(5) Delicensing
(d) Political Environment	(2) National economy
(e) Globalisation	(6) World Economy
(f) Legal Environment	(8) Judicial System
(g) Social Environment	(3) Values and demographic trends
(h) Economic Environment	(7) National Income Distribution

Write a word or a term or a phrase which can substitute each of the following statements

Question 1.
Controllable factor of the business environment
Answer:
Internal environment

Question 2.
The environment of business that includes economic condition, policies and system, basic philosophy, national income, money supply, trade cycle economic development.
Answer:
Economic environment

Question 3.
The environment of business that includes stability and peace in the country, specific attitudes of selected representative.
Answer:
Political environment

Question 4.
The environment of business which consist of factors such as climate, minerals, soil, landforms, rivers and oceans etc.
Answer:
Natural environment

Question 5.
The environment of business which consist of the methods and techniques adopted for production.
Answer:
Technological environment

Question 6.
The environment of business which regulates and controls within the legal framework of a country.
Answer:
Legal environment

Question 7.
The process of eliminating unnecessary controls and restrictions for smooth functioning of business.
Answer:
liberalization

Question 8.
The process of integration of national economy with world through cross country information, ideas, technologies, goods, services and people.
Answer:
Globalization

Question 9.
The process of reducing the involvement of state or public sectors by involving of private sector in economic activities.
Answer:
Privatization.

State whether the following statements are True or False

Question 1.
Internal factors of business environment are uncontrollable factors.
Answer:
False

Question 2.
Business and Environment are independent.
Answer:
False

Question 3.
Social Environment is not important for business.
Answer:
False

Question 11.
Business Environment consists of internal as well as external factors.
Answer:
True

Question 4.
All business from are affected by the government and its policies.
Answer:
True

Question 5.
Liberalization of Indian economy resulted into easy entry of foreign business in India.
Answer:
True

Question 6.
Privatisation is an effective tool for restriction and reforming the public sector.
Answer:
True

Find the odd word out

Question 1.
Legislature, Government Shareholders.
Answer:
Shareholders

Question 2.
Social, Employees, Legal.
Answer:
Employees

Question 3.
Judiciary, Social values, Traditions.
Answer:
Judiciary

Question 4.
Value system, Human Resources, Marketing Resources.
Answer:
Marketing Resources

Question 5.
Liberalization, Socialization, Globalization.
Answer:
Socialization,

Question 6.
Technological, Weather, Climate.
Answer:
Technological

Question 7.
Social aspects, Economical aspect, Traditions.
Answer:
Economical aspect

Question 8.
Capitalist Economy, Mixed Economy, Indian Economy.
Answer:
Indian Economy

Question 9.
Indian Contract Act 1872, Indian Partnership Act 1932, Industrial Dispute Act 1947.
Answer:
Indian Partnership Act, 1932

Question 10.
Natural Environment, Economic Environment, Political Environment.
Answer:
Natural Environment.

Complete the sentence

Question 1.
The business environment constitute threats to the firm and offers ………………… for potential market.
Answer:
opportunities

Question 2.
Every society develops its own ………………… which means how the members of that society between and interact with each other.
Answer:
culture

Question 3.
Indian political system comprises of three vital institution like …………………, ………………… and Judiciary.
Answer:
Legislature, Government

Question 4.
………………… changes are fast and to keep pace with it, business should be ever alert.
Answer:
Technological

Question 5.
All nation would be interdependent in the ………………… economy.
Answer:
Global.

Select the correct option

Question 1.
Which analysis will enable managers to deal with business challenges?
(Environmental / Data / Political)
Answer:
Environmental

Question 2.
Which factor of Business Environment are regarded as uncontrollable?
(Internal / External)
Answer:
External

Question 3.
Trade and commerce between two nations are dependent on which factors?
(Social / Geographic / Technological)
Answer:
Geographic

Question 4.
Which is the most powerful institution in the Indian Political system?
(Legislature / Government / Judiciary)
Answer:
Legislature

Question 5.
In which economic system factors of productions are organized .managed and oriented by government?
(Capitalist / Socialist / Mixed)
Answer:
Socialist

Question 6.
Which economic system is followed in India?
(Capitalist / Socialist / Mixed)
Answer:
Mixed

Question 7.
Which of the following has created on economically interdependent international environment?
(Liberalisation / Privatisation / Globalisation)
Answer:
Globalisation

Correct the underline word and rewrite the following sentence

Question 1.
Internal factors of Business Environment are uncontrollable.
Answer:
External factors of Business Environment are uncontrollable.

Question 2.
External factor of business are controllable.
Answer:
Internal factor of business are controllable.

Question 3.
Vision, mission and objectives of business are related to External factors.
Answer:
Vision, mission and objectives of business are related to Internal factors.

Question 4.
Social trends and social values are part of economic environment.
Answer:
Social trends and social values are part of social environment.

Question 5.
Factors like climate, minerals, soil, river, etc. are elements of political environment.
Answer:
Factors like climate, minerals, soil, river, etc. are elements of natural environment.

Question 6.
Socialist Economy is also known as free market economy.
Answer:
Capitalist Economy is also known as free market economy.

Question 7.
GST is part of political environment.
Answer:
GST is part of legal environment.

Question 8.
Privatisation has resulted into easy of foreign business in India.
Answer:
Liberalisation has resulted into easy of foreign business in India.

Question 9.
Globalisation is an effective tool for restricting and reforming the public sector.
Answer:
Privatisation is an effective tool for restricting and reforming the public sector.

Question 10.
Liberalisation means integration of natural economy with world economic.
Answer:
Globalisation means integration of natural economy with world economic.

Study the following case/situation and express your opinion.

1. Just after declaration of Lok Sabha 2014 result, the Bombay Stock Exchange Sensex rose by 1000 points in a day.

Question 1.
Identify the environmental factor which led to this rise giving reason.
Answer:
Rise in stock market index (sensex) is economic environment. But it has done due to political environment (Lok Sabha Election Results)

Question 2.
Explain any two other dimensions of the environment.
Answer:
Two other dimensions of the environment are (a) Legal environment and (b) Technological environment

2. Government of India is seriously thinking to allow oil marketing under public sector, by fixing their own price for petroleum products.

Question 1.
Name the economic reform related to this decision.
Answer:
Privatization is the economic reform related to this decision.

Question 2.
Name other two reforms recommended in new economic policy.
Answer:
The other two reforms recommended in new Economic policy are Liberalization and Globalization.

3. Today it is common to see computerized information Kiosks and Internet / Word Wide Web multimedia pages highlighting the virtues of products.

Question 1.
Name the dimension of business environment highlighted in this statement.
Answer:
Technological environment

4. An advertisement of baby product giving information to the potential buyers that “Mother Milk is the best”.

Question 1.
Name the component of business environment.
Answer:
Legal Environment.

5. Zero Defect Zero Effect(ZED) is a slogan coined by the PM of India, with reference to the Make in India initiative launched by the government. The Zed model aims to make India the manufacturer of the world and present the products in the global market.

Before the. initiative was launched, the limits of Foreign Direct Investment(FDI) in various sector had been released. The application for licenses was made available Online and various other norms and production were also considered by the government.

Question 1.
From the above, identify the major components of New Economic Policy of 1991.
Answer:
Liberalization and Globalization.

Question 2.
In the light of the above discussion explain the component of NEP 1991.
Answer:

1. Liberalization : It refers to the process of eliminating unnecessary controls and restrictions for smooth functioning of business.
2. Privatization : It refers to reduce the involvement of state or public sectors by involving of private sector in economic activities.
3. Globalization : It refers to integration of national economy and societies through cross country flows of information, ideas, technologies, goods, services, capital, finance and people.

6. It is interesting to know that the menu items of multinational food chains are customized to suit the general palates of the local people in the region. When it started business in India in the year 1996, the company went through a complete location strategy. Me Donald’s changed its product menu to accommodate the vegetable burger given the large population. It priced the products by close to 15%. Also, the Mc-Aloo Tikki burger ‘is not available anywhere but in the Indian outlets of Me Donalds.

Question 1.
Identify the relevant feature of business environment discussed in the case above.
Answer:
Relativity is the feature of business environment discusses in the case above.

Question 2.
State the other features of business environment.
Answer:

1. The features of business environment are:
2. Determining opportunities and threats
3. Identifying firm’s strength and weakness
4. Continuous learning
5. Image Building
6. Meeting Competition
7. Giving Direction for growth

7. Ultra paint company which is manufacturing paints has been enjoying a prominent market position as it manufactured best quality paints, made timely payment of taxes to government. It assembled various inputs like finance, machines, raw material, etc. from its environment. But since last year it has been dumping its untreated possessions waste on the river bank which has created many health problems for the people. As a result, the court passed an order to seal the manufacturing unit of the company.

Question 1.
State the importance of business environment highlighted in the above case.
Answer:
Business environment helps in tapping useful resources.

Question 2.
Identify any two dimension of business environment mentioned in the above case and comment.
Answer:

1. Social environment : “It has been dumping untreated possession of waste on river bank problems” for people. This shows that it is at the cost of human life as their life is affected.
2. Legal Environment : “The court passed on order to seal the company”. It shows that through court interference the company was sealed.

Question 3.
State any two values which have been overlooked by the company.
Answer:
Company overlooked Environment protection, concern for human life, respect for law and order and social responsibility.

Balbharti Maharashtra State Board 11th OCM Important Questions Chapter 8 Introduction to Management Important Questions and Answers.

Maharashtra State Board 11th Commerce OCM Important Questions Chapter 8 Introduction to Management

Select the correct option and rewrite the sentences

Question 1.
Management is a …………………. process.
(a) stable
(b) continuous
(c) one time
Answer:
(b) continuous

Question 2.
Formulating the plan is the main function of …………………. level management.
(a) top
(b) middle
(c) lower
Answer:
(a) top

Question 3.
Important, decisions in the business are made by ………………….
(a) management
(b) administration
(c) organisation.
Answer:
(b) administration

Question 4.
Management is a profession because it has ………………….
(a) specialised knowledge
(b) training facilities
(c) code of conduct.
Answer:
(a) specialised knowledge

Question 5.
According to views expressed by different management authorities, management and administration are ………………….
(a) synonymous
(b) different
(c) synonymous and different.
Answer:
(c) synonymous and different.

Question 6.
Management is an …………………. to co-ordinate groun efforts attaining the cherished goals of the business.
(a) activity
(b) process
(c) objective.
Answer:
(a) activity

Question 7.
…………………. is the basic and motivating factor of management.
(a) Human element
(b) Capital
(c) Direction.
Answer:
(a) Human element

Question 8.
Top management does …………………. and …………………. function.
(a) supervisory
(b) operative
(c) determination and administration.
Answer:
(c) determination and administration.

Question 9.
Management is a …………………. activity.
(a) group
(b) individual
(c) social.
Answer:
(a) group

Question 10.
Management is a …………………. science.
(a) social
(b) physical
(c) natural.
Answer:
(a) social

Question 11.
There are …………………. levels of management in a organisation.
(a) two
(b) four
(c) three.
Answer:
(c) three.

Question 12.
Management means to ………………….
(a) order
(b) co-ordinate
(c) help.
Answer:
(b) co-ordinate

Question 13.
Management motivates the emplovees to ………………….
(a) work hard
(b) take initiative
(c) earn more.
Answer:
(a) work hard

Question 14.
Management ensures the optimum use of ………………..
(a) blackmoney
(b) resources
(c) international market.
Answer:
(b) resources

Match the pairs

Question 1.

Part A	Part B
(a) Management	(1) Administration function
(b) Policy Making	(2) Human knowledge
(c) Thinking Function	(3) Top level management
(d) Doing Function	(4) Lower level management
(e) Top level management	(5) Middle level management
	(6) Management function
	(7) Knowledge of Administration
	(8) Board of Directors

Answer:

Part A	Part B
(a) Management	(2) Human knowledge
(b) Policy Making	(3) Top level management
(c) Thinking Function	(1) Administration function
(d) Doing Function	(6) Management function
(e) Top level management	(8) Board of Directors

Question 2.

Part A	Part B
(a) Management	(1) Regular practice
(b) Management as an Art	(2) Can be seen
(c) Top Level Management	(3) Administration
(d) Management as a Profession	(4) Universal in nature
(e) Lower Level Management	(5) Code of conduct
	(6) Evaluate performance
	(7) Foreman
	(8) Selective
	(9) Directing subordinates to complete task
	(10) Cause effect relationship

Answer:

Part A	Part B
(a) Management	(4) Universal in nature
(b) Management as an Art	(1) Regular practice
(c) Top Level Management	(6) Evaluate performance
(d) Management as a Profession	(5) Code of conduct
(e) Lower Level Management	(7) Foreman

Question 3.

Part A	Part B
(a) Systematic Body of knowledge	(1) Top level management
(b) Lower level management	(2) Management as an art.
(c) Management as universal process	(3) Board of Directors.
(d) Management as profession	(4) Practice oriented
(e) Direction and control.	(5) Service motive
	(6) Technical skills
	(7) Applicable to all organization.
	(8) Management as a science.
	(9) Applicable to business organization

Answer:

Part A	Part B
(a) Systematic Body of knowledge	(8) Management as a science.
(b) Lower level management	(6) Technical skills
(c) Management as universal process	(7) Applicable to all organization.
(d) Management as profession	(5) Service motive
(e) Direction and control.	(1) Top level management

Give one word / phrase / term

Question 1.
The activity which aims at achieving a definite goal.
Answer:
Management

Question 2.
Level of management requiring analytical or conceptual skill.
Answer:
Top level management

Question 3.
Another name for lower level management.
Answer:
Supervisory or Operational level

Question 4.
Level of management requiring human skills.
Answer:
Middle level management

Question 5.
Level of management which performs administrative functions.
Answer:
Top level management

Question 6.
Level of management that takes policy decision.
Answer:
Top level management

Question 7.
The highest level of management in the hierarchy.
Answer:
Top level management

Question 8.
The level which executes the policy.
Answer:
Middle level management

Question 9.
The level of management which requires few people.
Answer:
Top level management

Question 10.
The level of management which requires large number of persons.
Answer:
Lower level management

Question 11.
Levels of management which consists of supervisors and foremen.
Answer:
Lower level management

Question 12.
Level of management which consists of departmental managers.
Answer:
Middle level management

Question 13.
Level of management which consists of chairman and board of directors.
Answer:
Top level management

Question 14.
State the level of management in which Class-I executives are involved.
Answer:
Top level management

Question 15.
The art of directing and inspiring people.
Answer:
Management

Question 16.
The application of skill and knowledge to bring the desired result.
Answer:
Management as an art

Question 17.
Level of management that evaluates the performance of various departments.
Answer:
Top level management.

State True or False

Question 1.
There are no separate levels of management in an organization.
Answer:
False

Question 2.
Management aims at achieving goals for its organization.
Answer:
True

Question 3.
Management is an universal process.
Answer:
True

Question 4.
Management aims at achieving goals for its organization.
Answer:
True

Question 5.
Management is a profession.
Answer:
True

Question 6.
Management is a continuous process.
Answer:
True

Question 7.
Management aims at achieving business objectives.
Answer:
True

Question 8.
Objective of management is to obtain minimum output and maximum input.
Answer:
False

Question 9.
Management has to maintain good relations with all.
Answer:
True

Question 10.
Management is a perfect art.
Answer:
False

Question 11.
Management is neither a pure science nor a fine art.
Answer:
True

Question 12.
Profession do not have any ethics or code of conduct.
Answer:
False

Question 13.
Board of Directors are the part of lower management.
Answer:
False

Question 14.
The top level management is administrative in nature.
Answer:
True

Question 15.
The managers receive orders and instructions from lower level of management.
Answer:
False

Question 16.
Middle level management interprets and communicates the policies to top level management.
Answer:
False

Question 17.
Management is an art, a science and a profession.
Answer:
True

Question 18.
We cannot make any changes in the field of management.
Answer:
False

Question 19.
The professional manager does not need special knowledge and skill.
Answer:
False

Question 20.
Management is required to conduct business as well as non-business activity.
Answer:
True

Question 21.
Management helps in using the resources properly.
Answer:
True

Question 22.
Management is required even for a very small business.
Answer:
True

Question 23.
Management is an art only.
Answer:
False

Question 24.
Management cannot be considered as a business.
Answer:
True

Question 25.
Top level management performs the function of planning.
Answer:
True

Question 26.
Lower level management is engaged in the policy making.
Answer:
False

Question 27.
Levels of management are done according to the size of the organization.
Answer:
True

Find the odd one

Question 1.
Characteristics of Management Goal-oriented, Group Activity, Tangible, Continuous process.
Answer:
Tangible.

Complete the sentences

Question 1.
Administration is the involvement of ………………. management.
Answer:
Top

Question 2.
………………. deals with setting, seeking and reaching objectives.
Answer:
Management

Question 3.
Management has ………………. objectives.
Answer:
pre-determined

Question 4.
Supervisor level of management is directly linked to the ………………. functions of the firm.
Answer:
Routine

Question 5.
Lower level management is also known as ………………. management.
Answer:
Supervisory

Question 6.
………………. is an art of getting things done through others.
Answer:
Management

Question 7.
Generally there are ………………. levels of management in the organisation.
Answer:
Three

Question 8.
Management is ………………. oriented.
Answer:
Goal

Question 9.
Management is a ………………. science.
Answer:
Social

Question 10.
At the ………………. level of management, personnel are few.
Answer:
Top

Question 11.
Management means to ……………….
Answer:
Co-ordinate

Question 12.
Management has to satisfy unlimited want through limited ……………….
Answer:
Means

Question 13.
Management is an ………………. of getting work done through others.
Answer:
Art

Question 14.
Management is co-ordination of ………………. and physical resources.
Answer:
Human

Question 15.
A professional charges ………………. for his services.
Answer:
Fees

Question 16.
Management is done to achieve ……………….
Answer:
Goal/objective

Question 17.
Management is getting things done through ……………….
Answer:
Others

Question 18.
The word management is derived from Italian word ……………….
Answer:
Maneggiare

Question 19.
Implementation of policies is the function of ………………. level management.
Answer:
Lower

Question 20.
Every profession has a ………………. of conduct.
Answer:
Code

Question 21.
Management is derived from ………………. words.
Answer:
Two Latin.

Select the correct option

Question 1.
(Levels of Management, Lower Level Management, Management, Code of conduct, Board of Directors).

Part A	Part B
(1) Continuous Process	—————
(2) —————	Top Level Management
(3) Top, Middle, Lower	—————
(4) Profession	—————
(5) ————-	Lower Level Management

Answer:

Part A	Part B
(1) Continuous Process	Management
(2) Board of Directors	Top Level Management
(3) Top, Middle, Lower	Levels of Management
(4) Profession	Code of conduct
(5) Supervisory Level	Lower Level Management

Answer in one sentence

Question 1.
What is Italian word for ‘manage’.
Answer:
Italian word for ‘manage’ is ‘maneggiare’ meaning to handle.

Question 2.
Name the executive related to top level management.
Answer:
Executives related to top level management are – Board of Directors, President, Chief Executive Officer, Directors, etc.

Question 3.
Name the executives related to middle level management.
Answer:
Executives related to middle level management are Finance manger, Production manager, Sales manager, etc.

Correct the underlined word and rewrite the following sentences

Question 1.
Management is tangible in nature.
Answer:
Management is intangible in nature.

Question 2.
Management is one time process.
Answer:
Management is continuous process.

Question 3.
Administration is an art of getting things done through others.
Answer:
Management is an art of getting things done through others.

Question 4.
Management is static in character.
Answer:
Management is dynamic in character.

Question 5.
Top Level Management decides short term objectives of the organization.
Answer:
Top Level Management decides long term objectives of the organization.

Question 6.
Finance Manager is an example of lower level management.
Answer:
Superintendent is an example of lower level management.

Question 7.
Drawing, Cycling is a science.
Answer:
Drawing, Cycling is an art.

Study the following case/situation and express your opinion

1. Shankar Patil is an advocate and he is running his profession in a very good manner. His younger brother Prashant Patil has done very beautiful and artistic decoration of his brother’s office with seating arrangement and symbol of Justice as his hobby. Vishwas Patil, older brother of Shankar Patil is a science graduate and doing farming in best way. He exports the farm production.

On the basis of above information:
Question 1.
Identify the source of income of Shankar Patil.
Answer:
Shankar Patil is a lawyer by profession. He is practicing as a Lawyer / an advocate. He render his services to his clients and against that charges fee from them. So, ‘fee’ is the income source of Shankar Patil.

Question 2.
What is the qualification of Prashant Patil as a decorator?
Answer:
Prashant Patil may be or may not be a professional interior decorator. His hobby is decorating the office / houses. He may be an artist and an art does not require any formal education.

Question 3.
Mention two features of profession.
Answer:
Following are the features of profession:
1. Formal Education : Profession needs formal education. Today managers are qualified with management diploma or degrees. They take formal training from management schools which help them to work with perfection.

2. Restricted Entry : The entry in any profession is restricted. It needs a formal education. For example- Lawyer, Doctor, Interior designs, Architect, Chartered Accountant, etc. Such compulsion is not there for becoming a manager.

Justify the following statements

Question 1.
Management is an universal process.
Answer:

1. Management is applicable to all organization whether religious, social or cultural, educational or governmental or non-governmental.
2. All kind of organization have accepted management, as it is required everywhere.
3. Every activity which has to be performed by a group of persons requires effective planning, organizing, co-ordinating, and controlling.
4. Thus, management is an universal process.

Question 2.
There are levels of management in an organization.
Answer:

1. There are three levels of management in an organization.
2. The top level which consists of chairman, board of directors, etc takes care of formulating the board policies of the organization.
3. The middle level does the work of implementing and executing the orders to the lower level.
4. The lower level management does the actual and execution and operating activities.
5. All the three levels are important and they are dependent on each other.
6. Thus, all three levels are required for effective operation of the organization.

Question 3.
Management is a profession.
Answer:

1. It is a specialized body of knowledge and managers are required to have professional skill and training
   to be efficient.
2. It has certain ethical standards.
3. Its motive is service oriented.
4. It requires training which is formal.
5. Thus, Management is considered as a profession.

Question 4.
Management is neither a pure science nor a fine art.
Answer:

1. Management is said to be both an art and a science, as science teaches one to know and art teaches what to do.
2. Management is a science as it is a body of knowledge and generalisation that represents the truth and facts, but it is not a pure science like Physics, Chemistry and Biology.
3. Management is an art of applying the knowledge, but not pure fine arts like painting, dancing, etc.
4. Thus, Management is neither a pure science nor a fine art.

Question 5.
Profession has ethics or code of conduct.
Answer:

1. Profession is well-defined as an occupation which requires specialized skills and ethical standards.
2. Professional managers have to follow code of conduct and ethical standards laid down by the All India Management in India.
3. If they do not follow the code of conduct they can be derecognised and disqualified from the profession.
4. Thus, Profession has ethics and code of conduct.

Question 6.
Management is an art, a science and a profession.
Answer:

1. Management is an art because every manager has to apply his skills, intelligence, creativity for the efficient execution of management activities.
2. It is considered a science because it adopts the cause and effect relationship.
3. It has a scientific approach but deals in human behaviour, therefore called social science.
4. Management is also considered a profession because it is a specialized body of knowledge and managers are required to have professional skills and training to be efficient.
5. Thus, Management is an art, a science, and a profession.

Attempt the following

Question 1.
State the functions of lower-level management.
Answer:
The functions of lower-level management are as follows:

1. Planning day to day working.
2. Acting as a link between the middle level of management and workers.
3. Carrying out the instructions given by the middle-level management.
4. Delegating duties to workers, inspecting and supervising their work.
5. Attending to the problems of workers and making arrangements for their training and development.
6. To maintain discipline and good human relations among the workers.
7. Image building of the enterprise before workers and creating a sense of belongingness.
8. Ensuring the safety of workers, machines, tools, etc.
9. Making arrangements of materials and tools and preventing the misuse and wastage of such material.
10. Providing feedback information about the worker’s problems to the higher authorities.