1. Reabsorption of useful substances from glomerular filtrate occurs in
(a) Collecting tube
(b) Loop of Henle
(c) Proximal convoluted tubule
(d) Distal convoluted tubule
2. Brush border is characteristic of
(a) neck of nephron
(b) collecting tube
(c) proximal convoluted tubule
(d) all the above
3. Proximal and distal convoluted tubules are parts of
(a) Seminiferous tubules
(b) Nephron
(c) Oviduct
(d) Vas deferens
4. Under normal conditions which one is completely reabsorbed in the renal tubule?
(a) Urea
(b) Uric acid
(c) Salts
(d) Glucose
5. Nitrogenous waste products are eliminated mainly as
(a) urea in tadpole and ammonia in adult frog
(b) ammonia in tadpole and urea in adult frog
(c) urea in both tadpole and adult frog
(d) urea in tadpole and uric acid in adult frog
6. Glucose is taken back from glomerular filtrate through
(a) Active transport
(b) Passive transport
(c) Osmosis
(d) Diffusion
7. Hair present in the skin are
(a) epidermal in origin and made of dead cells
(b) epidermal in origin and made of living cells
(c) dermal in origin and made of living cells
(d) dermal in origin and made of dead cells
8. Part not belonging to uriniferous tubule is
(a) Glomerulus
(b) Henle‘s loop
(c) Distal convoluted tubule
(d) Connecting tubule
9. If kidney fail to reabsorb water, the effect on tissue would
(a) remain unaffected
(b) shrink and shrivel
(c) absorb water from blood plasma
(d) take more O2 from blood
10. Uric acid is nitrogenous waste in
(a) Mammals and molluscs
(b) Birds and lizards
(c) Frog and cartilaginous fishes
(d) Insects and bony fishes
11. A patient suffering from cholera is given saline drip because
(a) Cl– ions are important component of blood plasma
(b) Na+ ions help to retain water in the body
(c) Na+ ions are important in transport of substances across membrane
(d) Cl– ions help in the formation of HCl in stomach for digestion
12. In Ornithine cycle, which one pair of the following wastes are removed from the blood?
(a) CO2 and urea
(b) CO2 and ammonia
(c) Ammonia and urea
(d) Urea and sodium salts
13. In ureotelic animals, urea is formed by the
(a) Arginine cycle
(b) Cori’s cycle
(c) Ornithine cycle
(d) EM pathway
14. The basic functional unit of the human kidney is
(a) nephron
(b) nephridia
(c) pyramid
(d) Henle’s loop
15. Solenocytes are the main excretory structures in
(a) Platyhelminthes
(b) Annelids
(c) Molluscs
(d) Echinodermates
16. In the renal tubules the permeability of the distal convoluted tubule and collecting duct to water is controlled by
(a) Vasopressin
(b) Aldosterone
(c) Growth hormone
(d) Renin
17. Formation of concentrated (hyperosmotic) urine in vertebrates generally depends on
(a) length of the proximal convoluted tubule
(b) length of Henle’s loop
(c) area of Bowman’s capsule epithelium
(d) capillary network forming glomerulus
18. The enteronephric nephridia of earthworm are concerned with
(a) osmoregulation
(b) excretion of nitrogenous wastes
(c) digestion
(d) respiration
19. Which one of the following is a matching pair?
(a) Tears-excretion of salts
(b) Sweat-thermoregulation
(c) Saliva-tasting food
(d) Sebum-sex attraction
20. In Hydra waste material of food digestion and nitrogenous waste material removed from
(a) mouth and body wall
(b) mouth and tentacles
(c) mouth and nematocyst
(d) body wall and tentacles
21. If Henle’s loop were absent from mammalian nephron, which of the following is to be expected?
(a) The urine will be more dilute
(b) There will be no urine formation
(c) There will be hardly any change in the quality and quantity of urine formed
(d) The urine will be more concentrated
22. When a fresh-water protozoan possessing a contractile vacuole, is placed in a glass containing marine water, the vacuole will
(a) increase in number
(b) disappear
(c) increase in size
(d) decrease in size
23. Uricotelism is found in
(a) Mammals and birds
(b) Fishes and fresh water protozoans
(c) Birds, reptiles and insects
(d) Frogs and toads
24. A terrestrial animal must be able to
(a) excrete large amounts of water in urine
(b) conserve water
(c) actively pump salts out through the skin
(d) excrete large amounts of salts in urine
25. A person is undergoing prolonged fasting. His urine will be found to contain abnormal quantities of:
(a) fats
(b) amino acids
(c) glucose
(d) ketones
26. The net pressure gradient that causes the fluid to filter out of the glomeruli into the capsule is:
(a) 50 mm Hg
(b) 75 mm Hg
(c) 20 mm Hg
(d) 30 mm Hg
27. In Ornithine cycle, which of the following wastes are removed from the blood?
(a) CO2 and urea
(b) Ammonia and urea
(c) CO2 and ammonia
(d) Urea and urine
28. Uric acid is the chief nitrogenous component of the excretory products of
(a) earthworm
(b) cockroach
(c) frog
(d) man
29. Bowman‘s glands are located in the
(a) anterior pituitary
(b) female re productive system of cockroach
(c) olfactory epithelium of our nose
(d) proximal end of uriniferous tubules.
30. Lysozyme that is present in perspiration, saliva and tears, destroys
(a) certain types of bacteria
(b) all viruses
(c) most virus-infected cells
(d) certain fungi
31. Consider the following four statements (a-d) about certain desert animals such as kangaroo, rat.
(a) They have dark colour and high rate of reproduction and excrete solid urine
(b) They do not drink water, breathe at a slow rate to conserve water and have their body covered with thick hairs
(c) They feed on dry seeds and do not require drinking water
(d) They excrete very concentrated urine and do not use water to regulate body temperature
Which two of the above
statements for such animals are true?
(1) 3 and 1
(2) 1 and 2
(3) 3 and 4
(4) 2 and 3
32. What will happen if the stretch receptors of the urinary bladder wall are totally removed?
(a) Micturition will continue
(b) Urine will continue to collect normally in the bladder
(c) There will be no micturition
(d) Urine will not collect in the bladder
33. Uric acid is the chief nitrogenous component of the excretory products of
(a) earthworm
(b) cockroach
(c) frog
(d) man
34. Which one of the following statements in regard to the excretion by the human kidneys is correct?
(a) Descending limb of Loop of Henle is impermeable to water
(b) Distal convoluted tubule is incapable of reabsorbing HCO3
(c) Nearly 99 per cent of the glomerular filtrate is reabsorbed by the renal tubules
(d) Ascending limb of Loop of Henle is impermeable to electrolytes
35. The principal nitrogenous excretory compound in humans is synthesised
(a) in kidneys but eliminated mostly through liver
(b) in kidneys as well as eliminated by kidneys
(c) in liver and also eliminated by the same through bile
(d) in the liver , but eliminated mostly through kidneys
36. Consider the following four statements (i-iv) regarding kidney transplant and select the two correct ones out of these.
(i) Even if a kidneytransplant is proper the recipient mayneed to take immune suppresants for along time
(ii) The cell mediated immune response is responsible for the graft rejection
(iii) The B lymphocytes are responsible for rejection of the graft
(iv)The acceptance or rejection of a kidneytransplant depends on specific interferons The two correct statements are:
(a) (ii) and (iii)
(b) (iii) and (iv)
(c) (i) and (iii)
(d) (i) and (ii)
37. Which one of the following is not a part of a renal pelvis?
(a) Peritubular capillaries
(b) Convoluted tubules
(c) Collecting ducts
(d) Loops of Henle
38. A large proportion of oxygen is left unused in the human blood even after its uptake by the body tissues. This O2
(a) acts as a reserve during muscular exercise
(b) raise the pCO2 of blood to 75 mm of Hg.
(c) is enough to keep oxyhaemoglobin saturation at 96%
(d) helps in releasing more O2 to the epithelial tissues.
39. Which one of the following correctly explains the function of a specific part of a human nephron?
(a) Podocytes: create minute spaces (slite pores) for the filtration of blood into the Bowman‘s capsule
(b) Henle‘s loop: most reabsorption of the major substances from the glomerular filtrate
(c) Distal convoluted tubule: reabsorption of K+ ions into the surrounding blood capillaries
(d) Afferent arteriole: carries the blood away from the glomerular towards renal vein.
40. Which one of the following statements is correct with respect to kidney function regulation?
(a) When someone drinks lot of water,ADH release is suppressed.
(b) Exposure to cold temperature blood flow stimulates formation of Angiotensin II.
(c) An increase in glomerular blood flow stimulates formation of Angiotensin II.
(d) During summer when body loses lot of water by evaporation, the release of ADH is suppressed.
41. Uricotelic mode of passing out nitrogenous wastes is found in
(a) Reptiles and Bird
(b) Birds and Annelids
(c) Amphibians and Reptiles
(d) Insects and Amphibians
42. Ureters act as urogenital ducts in
(a) human males
(b) human females
(c) frog’s both males and females
(d) frog’s males
43. The maximum amount of electrolytes and water (70 – 80 percent) from the glomerular filtrate is reabsorbed in which part of the
nephron?
(a) Ascending limb of loop of Henle
(b) Distal convoluted tubule
(c) Proximal convoluted tubule
(d) Descending limb of loop of Henle
44. Which one of the following options gives the correct categorization of six animals according to the type of nitrogenous wastes (A, B, C), they give out?
A-Ammonotelic —- B-Ureotelic —- C-Uricotelic
(a) Pigeon, Humans — Aquatic Amphibia, Lizards –Cockroach, Frog
(b) Frog, Lizards — Aquatic Amphibia, Humans — Cockroach, Pigeon
(c) Aquatic Amphibia — Frog, Humans — Pigeon, Lizards, Cockroach
(d) Aquatic Amphibia –Cockroach, Humans– Frog, Pigeon, Lizards
45. A fall in glomerular filtration rate (GFR) activates
(a) adrenal cortex to release aldosterone.
(b) adrenal medulla to release adrenaline.
(c) juxta – glomerular cells to release renin.
(d) posterior pituitary to release vasopressin.
46. Which one of the following characteristics is common to both in humans and adult frogs?
(a) Four – chambered heart
(b) Internal fertilization
(c) Nucleated RBCs
(d) Ureotelic mode of excretion
47. Select the option which shows correct matching of animal with excretory organs and excretory product Animal Excretory Excretory organs
product
(a) Housefly Renal tubules Uric acid
(b) Labeo (Rohu) Nephridial Ammonia tubes
(c) Salamander Kidney Urea
(d) Peacock Kidney Urea
48.Which of the following statements is correct?
(a) The descending limb of loop of Henle is impermeable to water.
(b) The ascending limb of loop of Henle is permeable to water.
(c) The descending limb of loop of Henle is permeable to electrolytes.
(d) The ascending limb of loop of Henle is impermeable to water.
49.Which of the following does not favour the formation of large quantities of dilute urine?
(a) Renin
(b) Atrialnatriuretic factor
(c) Alcohol
(d) Caffeine
50. In which of the following minimum content of urea is present ?
(a) Hepatic portal vein
(b) Portal vein
(c) Renal vein
(d) Vena cava
51.Which of the following causes an increase in sodium reabsorption in the distal convoluted tubule?
(a) Increase in aldosterone levels
(b) Increase in antidiuretic hormone levels
(c) Decrease in aldosterone levels
(d) Decrease in antidiuretic hormone levels
52.Which one of the following characteristics is common both in humans and adult frogs?
(a) Four chambered heart
(b) Internal fertilization
(c) Nucleated RBCs
(d) Ureotelic mode of excretion
53. A fall in glomerular filtration rate (GFR) activates
(a) adrenal cortex to release aldosterone.
(b) adrenal medulla to release adrenaline.
(c) juxta – glomerular cells to release renin.
(d) posterior pituitary to release vasopressin.
54.Uricotelic mode of excreting nitrogenous wastes is found in
(a) birds and annelids
(b) reptiles and birds
(c) insects and amphibians
(d) amphibians and reptiles
55.ADH influences water permbeality in the
(a) Regulation of blood pressure
(b) Regulation of acidity of fluids
(c) Removal of urea
(d) secretion of antibiotics
56.What will happen if the stretch receptors of the urinary bladder wall are totally removed?
(a) Micturition will continue
(b) There will be no micturition
(c) Urine will not collect in the bladder
(d) Urine will continue to collect normally in the bladder
57.Human urine is usually acidic because :
(a) excreted plasma proteins are acidic
(b) potassium and sodium exchange generates acidity.
(c) the sodium transporter exchanges one hydrogen ion for each sodium ion, in peritubular capillaries.
(d) hydrogen ions are actively secreted into the filtrate
58.Which one of the following statements in regard to the excretion by the human kidneys is correct?
(a) Descending limb of Loop of Henle is impermeable to water
(b) Nearly 99 per cent of the glomerular filtrate is reabsorbed by the renal tubules
(c) Distal convoluted tubule is incapable of reabsorbing HCO3
(d) Ascending limb of Loop of Henle is impermeable to electrolytes
59. Angiotensinogen is a protein produced and secreted by
(a) juxtaglomerular (JG) cells
(b) endothelial cells (cells lining the blood vessels)
(c) macula densa cells
(d) liver cells
60.Proboscis gland is balanoglossus is associated with
(a) Digestion
(b) Circulation
(c) Excretion
(d) Respiration
61. A person is undergoing prolonged fasting. His urine will be found to contain abnormal quantities of
(a) amino acids
(b) fats
(c) ketones
(d) glucose
62.Conversion of ammonia to urea is done by
(a) arginine cycle
(b) fumaric cycle
(c) ornithine cycle
(d) citrulline cycle
63. Deamination is process in which …
(a) Poisonous urea is removed from the blood and it occures in kidney
(b) Amino acid is absorbed from the digested food and it occur in intestinal
(c) Amino acid combined with ammonia to from protein
(d) Amino acid broken down to release CO2 and NH2
64. The ornithine cycle removes two waste products from the blood in liver. These products are
(a) CO2 and ammonia
(c) CO2 and urea
(c) ammonia and uric acid
(d) ammonia and urea.
65.Glucose is taken back from glomerular filtrate through
(a) active transport
(b) passive transport
(d) diffusion
(d) osmosis
66. Which one of the following statements is correct with respect to kidney function regulation?
(a) When someone drinks lot of water, ADH release is suppressed.
(b) Exposure to cold temperature stimulates ADH release.
(c) An increase in glomerular blood flow stimulates formation of angiotensin II.
(d) During summer when body loses lot of water by evaporation, the release of ADH is suppressed.
67. Uric acid is the chief nitrogenous component of the excretory products of
(a) earthworm
(b) cockroach
(c) frog
(d) man
68. Which of the following statements is correct ?
(a) The descending limb of loop of Henle is impermeable to water.
(b) The ascending limb of loop of Henle is permeable to water.
(c) The descending limb of loop of Henle is permeable to electrolytes.
(d) The ascending limb of loop of Henle is impermeable to water.
69. Match the items given in Column I with those in Column II and select the correct option given below:
Column I Column II
(Function) (Part of Excretory system)
a.Ultrafiltration i. Henle’s loop
b. Concentration ii. Ureter of urine
c. Transport of urine iii.Urinary bladder
d. Storage of iv. Malpighian urine corpuscle
v. Proximal convoluted tubule
a b c d
(1) iv v ii iii
(2) iv i ii iii
(3) v iv i iii
(4) v iv i ii
70. Match the items given in Column I with those in Column II and select the correct option given below :
Column I Column II
a. Glycosuria i. Accumulation of uric acid in joints
b. Gout ii. Mass of crystallized salts within the kidney
c. Renal calculi iii. Inflammation in glomeruli
d. Glomerular iv. Presence of in nephritis glucose urine
a b c d
(1) iii ii iv i
(2) i ii iii iv
(3) iv i ii iii
(4) ii iii i iv
71. Which of the following factors is responsible for the formation of concentrated urine?
(a) Low levels of antidiuretic hormone
(b) Maintaining hyperosmolarity towards inner medullary interstitium in the kidneys.
(c) Secretion of erythropoietin by Juxtaglomerular complex
(d) Hydrostatic pressure during glomerular Filtration
72. Use of an artificial kidney during hemodialysis may result in :
(a) Nitrogenous waste build-up in the body
(b) Non-elimination of excess potassium ions
(c) Reduced absorption of calcium ions from gastro-intestinal tract
(d) Reduced RBC production
Which of the following options is the most appropriate?
(1) (a) and (b) are correct
(2) (b) and (c) are correct
(3) (c) and (d) are correct
(4) (a) and (d) are correct
73. Presence of which of the following conditions in urine are indicative of Diabetes Mellitus?
(a) Ketonuria and Glycosuria
(b) Renal calculi and Hyperglycaemia
(c) Uremia and Ketonuria
(d) Uremia and Renal Calculi
74. Select the favourable conditions required for the formation of oxyhaemoglobin at the alveoli.
(a) Low pO2 , low pCO2 , more H+ , higher temperature
(b) High pO2 , low pCO2 , less H+ , lower temperature
(c) Low pO2 , high pCO2 , more H+ , higher temperature
(d) High pO2 , high pCO2 , less H+ , higher Temperature
75. Match List-I with List – II
List – I List II
(a) Allen’s Rule (i) Kangaroo rat
(b) Physiological adaptation (ii) Desert lizard
(c) Behavioural adaptation (iii) Marine fish at depth
(d) Biochemical adaptation (iv) Polar seal
Choose the correct answer from the options given below.
(a) (b) (c) (d)
(1) (iv) (iii) (ii) (i)
(2) (iv) (ii) (iii) (i)
(3) (iv) (i) (iii) (ii)
(4) (iv) (i) (ii) (iii)
Solutions :
1.Solution: (c)From Bowman’s capsule, glomerular filtrate enters the proximal convolute tubule. Most of the useful substances like Glucose (all), Amino Acids (all), most of the inorganic ions (Na+, K+, Cl– etc), most of the important buffer bicarbonates are reabsorbed in Proximal Convoluted Tubule.
Cells are specially adaptive for absorption having numerous microvilli & mitochondria (to provide energy for active absorption).
2.Solution: (c)
3. Solution: (b)Nephron is the excretory unit of human excretory system. Each nephron has a Bowman‘s Capsule, a Proximal Convoluted Tubule (PCT), Loop of Henle (Descending & Ascending limbs) and Distal Convoluted Tubule (DCT) which then enter into collecting duct.
4.Solution: (d)The cells of Proximal Convoluted Tubule (PCT) reabsorb entire glucose, amino acids, most of the inorganic ions (Na+, K+, Cl–) much of the water as well as some urea. Glucose is reabsorbed actively and most effectively.
5.Solution: (b)Ammonia molecules are small and very soluble in water. In ammonotelic animals large amount of H2O is required to eliminate ammonia from the body, so it is found in aquatic animals like tadpole of frog. When tadpole becomes a mature frog it acquires mainly ureotelism.
6.Solution: (a)Active transport.
7.Solution: (a)Each hair is present in a tubular pit called hair follicle. Living cells are only present at the base of hair known as hair papilla, rest of the hair is dead and divisible into outer cuticle, middle cortex & inner medulla.
8.Solution: (a)Glomerulus is a group of about 50 capillaries which have numerous pores and are separated by the lumen of Bowman‘s Capsule through a basement layer.
9.Solution: (b)If kidneys fail to reabsorb water the urine will be diluted causing polyuria (frequent urination). Then the body tissues get dehydrated & the cell will loose water content & shrink.
10.Solution: (b) The excretion of uric acid is called uricotelism. The excretion of uric acid is advantageous for those animals which have
to conserve water for their survival like birds and lizards.
11.Solution: (b)
In patients affected with cholera, a cholera enterotoxin is produced which results in increased synthesis of intracellular cyclic AMP, which in turn increases the permeability of intestinal mucosa, leading to secretion of fluid throughout the small intestine. Hence the patient is given saline
drip whereby Na+ ions restore the osmotic balance by retaining water in the body.
12.Solution: (b)
In ureotelic animals urea is formed from ammonia by Ornithine cycle. CO2 + 2NH3 → CO(NH2) 2 + H2O ammonia Urea
13.Solution: (c)
In ureotelic animals urea is formed by Ornithine cycle. Urea is formed in the liver where two molecules of ammonia combine with one molecule of CO2 in presence of Ornithine, citrulline, arginine and enzyme arginase. This is called Ornithine cycle.
14.Solution: (a)
Nephridia are the excretory structures of annelids. Henle’s loop is a part of the nephron or uriniferous tubule of the vertebrate kidney.
15.Solution: (a)Solenocytes or flame cells or protonephridia are excretory organ inPlatyhelminthes (Flatworms). They excrete ammonia. In Annelids excretory structure are nephridia. In Molluscs sac like kidneys are excretory. In Echinodermata nitrogenous wastes are excreted through gills.
16.Solution: (a)Growth hormone, released by the anterior lobe of pituitary brings about body growth by synthesis and deposition of proteins in tissues. Renin secreted by special cells in kidneys regulates blood pressure. Aldosterone reduces Na+ elimination by helping active reabsorption from the nephric filtrate.
17.Solution: (b)Henle‘s loop is involved in osmoregulation and concentrating urine. Thus producing a hypertonic urine.
18.Solution: (b) The nephridia are the excretory organs. The nephridia in earthworm are – Septal nephridia, Pharyngeal nephridia and Integumentary nephridia. The septal nephridia do not discharge excretory fluid to the exterior rather it pour them into the intestine. Hence these are also called Enteronephric nephridia.
19.Solution: (b)Sweat regulates body temperature. Sweating also called perspiration or sometimes transpiration is the production and evaporation of a fluid, consisting primarily of water as well as a smaller amount of sodium chloride the main constituent of ―table salt‖, that is excreted by the sweat glands in the skin of mammals.
20.Solution: (a)Hydra being a coelenterate, has blind sac body plan. It has only one mouth which serves as the opening for ingestion and waste elimination besides diffusion across body wall.
21.Solution: (a)Henle‘s loop is associated with the concentration of urine and production of hypertonic urine.
22. Solution: (d) A fresh water protozoan when placed in marine water medium, faces a condition of preventing entry of salts and loss of water.
Hence the contractile vacuole will decrease in size.
23.Solution: (c) In uricotelic animals nitrogenous waste is eliminated in the form of uric acid. Ammonotelism is seen in aquatic animals wherein nitrogenous wastes is eliminated in the form of ammonia eg. Fishes, tadpole. Ureotelism is observed in human beings in which nitogenous waste is eliminated as urea.
24.Solution: (b) Terrestial animals have limited access to water. Hence they have to secrete hypertonic urine and conserve water. Choices (c) and (d) are characteristics of marine animals who need to overcome the problem of preventing entry of salts and loss of water. Choice (a) is characteristic of fresh water animals.
25.Solution: (d) Under fasting conditions and in uncontrolled diabetes, the liver produces large amount of ketone bodies like Acetoacetate, dihydroxy butyrate. The presence of excess ketone bodies in blood or urine is termed ketonemic and ketonuria respectively.
26.Solution: (c) (i) Glomerular capillary pressure (45 mm Hg) favours filteration. (ii) The colloidal osmotic pressure (due to plasma proteins,
particularly albumin) acts against filteration. Its value is ~20 mmHg. (iii) The filterate pressure due to the glomerular filterate filled in the Bowman‘s capsule also acts against filteration. Its value is ~10 mmHg. Net filteration pressure = 45 – (20 + 10) mm Hg = 15 mm of Hg (10 – 20 mm of Hg)
27.Solution: (c) Urea NH2 – CO – NH2 is formed from two molecules of ammonia and one molecule of carbon dioxide. A molecule of ammonia
combines with carbondioxide to form carbonyl phosphate. It reacts with ornithine to form citrulline. Citrulline accepts another molecule of NH4 + giving rise to arginine. Arginine is hydrolysed into urea and ornithine with the help of enzyme arginase.
28.Solution: (b)
Uric acid is the chief nitrogenous component of the excretory product of cockroach. Animals which live in dry conditions have to conserve water in their bodies. Therefore, they synthesise crystals of uric acid trom ammonia. Uric acid crystals are non-toxic and can be retained in the body for a considerable time. Uricotelic animals include most insects e.g. cockroach, reptiles and birds.
29.Solution: (c) Bowman‘s glands are located in the olfactory epithelium of our nose.
30.Solution: (a) Lysozyme is an antibacterial agent which is secreted by the major salivary glands.
31.Solution: (a) Characteristics of certain desert animals such as kangaroo, rat are etc. They feed on dry seeds and do not require drinking
water. • They excrete very concentrated urine and do not use water to regulate body temperature.
32. Solution: (c) Micturition is same as urination. Urination or micturition is the act of passing urine which is a reflex phenomenon. As urine
accumulates in bladder the stretch receptors are activated that pass the stimulus to the spinal cord. In the absence of stretch receptors the urine would get collected and probably overflow.
33.Solution: (b)
Uric acid is the chief nitrogenous component of the excretory product of cockroach. Animals which live in dry conditions have to conserve water in their bodies. Therefore, they synthesise crystals of uric acid trom ammonia. Uric acid crystals are non-toxic and can be retained in the body for a considerable time. Uricotelic animals include most insects e.g. cockroach, reptiles and birds.
34.Solution: (c)
Urine formation involves three main process called, glomerular filtration, reabsorption and secretion. A comparison of the volume of the filtrate formed per day (which is 180 litres per day) with that of urine released (about 1.5 litres) suggest that nearly 99 percent of the glomerular
filtrate is resorbed by the renal tubules. The descending limb of loop of Henle is permeable to water but impermeable to electrolytes. The ascending limb is impermeable to water but allows transport of electrolytes. Reabsorption of sodium ions and water takes place in distal convoluted tubule. Also, it is capable of reabsorption of HCO3.
35.Solution: (d) The principal nitrogenous excretory compound in humans is urea. It is synthesized in the mitrochondrial matrix
and cytosol of liver cells and eliminated through kidneys.
36.Solution: (d) Tissue and blood group matching are essential before undertaking kidney transplant. Even if kidney transplant is
proper, the recipient may need to take immuno suppresant all his/her life. The ability of body to differentiate self and nonself and the cell-mediated immune response is responsible for graft rejection.
37.Solution: (c)Renal pelvis is the innermost portion of kidney. So, collecting ducts are not a part of renal pelvis.
38.Solution: (a)A large portion of oxygen is left unused in the human blood even after its uptake by the body tissues. This O2 acts as a reserve during muscular exercise.
39.Solution: (a)Glome podocytes are highly specialized cells with a complex cytoarchitecture plays a major role in establishing the selective permeability of glomerular filtration barrier.
40.Solution: (a)When some one drinks lots of water, kidney release of ADH is suppressed.
41.Solution: (a) An uricotelic organism produces uric acid as a result of de-amination. Examples of such organism are birds and insects.
42.Solution: (d)In male frogs the sperms are carried through the ureters, hence in male, ureters are called urinogenital ducts.
43.Solution: (c)Nearly all the essential nutrients, and 70- 80 percent of electrolytes and H2O are reabsorbed by proximal convoluted tubules.
44.Solution: (c)Those animals that excrete ammonia are called as ammonotelic, eg. aquatic amphibia. Those animals that excrete urea are called as ureotelic, eg. frog, humans. Those animals that excrete uric acid are called as uricotelic, eg. pigeon, lizards, and cockroach.
45.Solution: (c) The amount of the filtrate formed by the kidneys per minute is called glomerular filtration rate (GFR). GFR in a healthy
individual is approximately 125 ml/ minute, i.e., 180 litres per day. A fall in GFR can activate the JG cells to release renin which can stimulate the glomerular blood flow and thereby the GFR back to normal. Renin converts angiotensinogen in blood to angiotensin I and further
angiotensin II. Angiotensin II being powerful vasoconstrictor increases the glomerular blood pressure and thereby GFR
46.Solution: (d) Adult frog and human exhibit ureotelism because there excretory waste product is urea.
47.Solution: (c)Salamander (Amphibia; Caudata
48.(d) The ascending limb of loop of Henle is impermeable to water.
49.(a) Caffeine acts as a diuretic and decreases water reabsorption from the nephrons and thus, more dilute urine is produced. Hence, its Renin that does not favour the formation of large quantities of dilute urine instead produces concentrated urine
50.(c) The renal veins are veins that drain the kidney. They connect the kidney to the inferior vena cava. They carry the blood filtered by the kidney. Renal vein carries blood from kidney to heart, after the blood has been filtered (purified) for all the waste elements, therefore it contains at least content of urea in it.
51.(a) The increase in aldosterone level causes and increase in sodium reabsorption is DCT. It is secreted by outer, layer of adrenal gland when aldosterone is present in the blood, all the Na+ in the filterate is reabsorbed. Retaining Na+ raises the osmotic pressure of the blood and reduces the water loss from the body.
52.(d) Ureotelic mode of excretion
53.(b) The kidneys have built-in mechanisms for the regulation of glomerular filtration rate. One such efficient mechanism is carried out by juxtaglomerular apparatus (JGA). JGA is a special sensitive region formed by cellular modifications in the distal convoluted tubule and the afferent arteriole at the location of their contact. A fall in GFR can activate the JG cells to release renin which can stimulate the glomerular blood flow and thereby the GFR come back to normal
54.(b) Reptile, birds, land snails and insects excrete nitrogenous waste as uric acid in the form of pellet of paste with a minimum loss of water and are called uricotelic animals.
55.(b) removal of urine
56. (c) Sensory stretch receptors are responsible for the stretch reflex. If these are removed then autonomic nervous system control will not be there and micturition will continue. Micturition is the expulsion of urine from the urinary bladder.
57.(d) Human urine is usually acidic because hydrogen ions are actively secreted into the filtrate.
58.(b) Urine formation involves three main processes namely, glomerular filtration, reabsorption and secretion, that takes place in different parts of the nephron. A comparison of the volume of the filtrate formed per day (180 litres per day) with that of the urine released (1.5 litres), suggest that nearly 99 percent of the filtrate is reabsorbed by the renal tubules. The descending limb of loop of Henle is permeable to water but almost impermeable to electrolytes. The ascending limb is impermeable to water but allows transport of electrolytes actively or passively. Conditional reabsorption ofNa’ and water takes place in distal convoluted tubule. It is also capable of reabsorption of HC03.
59.(d) Angiotensinogen is synthesized and secreted mainly by the liver and is found in the α-globulin fraction of plasma. Angiotensinogen (mRNA) is an α2-globulin precursor of angiotensin, and is a yin hormone produced in the liver, kidney, adrenal glands, brain, heart and blood vessels, and adipose tissues to cause vasoconstriction and regulate blood pressure.
60.(c) The excretory organ in Balanoglossus is a proboscis gland lying in front of the central sinus and projecting into the proboscis coelom. It excretes brown or yellow granules.
61.(c) If a person is undergoing prolonged fasting, his urine will be found to contain abnormal quantities of ketones. During fasting energy is obtained by the oxidation of reserved fats. As a result of fatty acid oxidation large amount of ketone bodies are produced such as acetoacetate, β -hydroxybutyrate and acetone.
62.(a) Conversion of ammonia to urea is done by ornithine cycle. The urea cycle or the ornithine cycle, describes the conversion reactions of ammonia into urea. Since these reactions occur in the liver, the urea is then transported to the kidneys, where it is excreted. The main purpose of the ornithine cycle is to eliminate toxic ammonia from the body. Eventually, ammonia and carbon dioxide are the two waste products removed from the body.
63.(d) Deamination is process in which amino acid broken down to release CO2 and NH2
64.(a) The ornithine cycle removes two waste products from the blood in liver. These products are CO2 and ammonia Ornithine cycle removes both ammonia and urea from the blood. It converts ammonia into urea (in liver) and transport it to kidneys by the blood.
65. (a) Glucose is taken back from glomerular filtrate through active transport in proximal convoluted tubule.
66.(a) Antidiuretic hormone (ADH) or Vasopressin increases the reabsorption of water in the distal convoluted tubule, collecting tubules and collecting ducts of the nephrons of the kidneys. As a result, the reabsorption of water from the glomerular filtrate is increased. When someone drinks lot of water, requirement of absorption of water decreases, so ADH release is suppressed.
67.(b) excretion of uric acid is known as uricotelism and the animals which excrete uric acid are called uricotelic. Cockroach shows uricotelism.
68. (d)As the thick ascending limb is impermeable to water, the interstitium becomes concentrated with ions, increasing the osmolarity. This drives water reabsorption from the descending limb as water moves from areas of low osmolarity to areas of high osmolarity.
69 (b)Ultrafiltration (UF) is a membrane filtration process similar to Reverse Osmosis, using hydrostatic pressure to force water through a semi-permeable membrane. The pore size of the ultrafiltration membrane is usually 103 – 106 Daltons. Ultrafiltration (UF) is a pressure-driven barrier to suspended solids, bacteria, viruses, endotoxins and other pathogens to produce water with very high purity and low silt density.
By means of a countercurrent multiplier system, which uses electrolyte pumps, the loop of Henle creates an area of high urea concentration deep in the medulla, near the papillary duct in the collecting duct system. … This process reabsorbs water and creates a concentrated urine for excretion.Urine is carried from kidney to bladder through ureter. Urinary bladder is concerned with storage of urine.
70(c)Renal glycosuria, also known as renal glucosuria, is a rare condition in which the simple sugar glucose is eliminated (excreted) in the urine despite normal or low blood glucose levels. Nephropathy can affect people with any type of diabetes because it results from damage due to high blood glucose.
Gout is caused by a condition known as hyperuricemia, where there is too much uric acid in the body. The body makes uric acid when it breaks down purines, which are found in your body and the foods you eat.Kidney stones (also called renal calculi ) are hard deposits made of minerals and salts that form inside your kidneys.Glomerular nephritis is the inflammatory condition of glomerulus characterised by proteinuria and haematuria.
71 (b)formation of concentrated urine in the mammalian kidney is effected by the production of a highly concentrated environment around the medullary collecting ducts in which the final concentrating process occurs by osmotic equilibration of the collecting duct contents with the hypertonie surroundings.
72 (c)dialysis eliminates urea and potassium from the body. As phosphate ions are eliminated during dialysis, along with that calcium ions are also eliminated. So, there will be reduced absorption of calcium ions from gastrointestinal tract. RBCs production will be reduced, due to reduced erythropoietin hormone.
73(a)Ketonuria (presence of ketone bodies) and glycosuria (presence of glucose) conditions in urine are indicative of diabetes mellitus.
Ketonuria is a medical condition in which ketone bodies are present in the urine. It is seen in conditions in which the body produces excess ketones as an indication that it is using an alternative source of energy.Renal glycosuria, also known as renal glucosuria, is a rare condition in which the simple sugar glucose is eliminated (excreted) in the urine despite normal or low blood glucose levels.
74(b) The factors favourable for the formation of oxyhaemoglobin at the alveolar level are; high pO2, low pCO2, less H+ concentration and lower
temperature. The conditions favourable for the dissociation of oxygen from oxyhaemoglobin at the tissue level are; low pO2 , high pCO2 , high H+ concentration and high temperature.
75(4)Allen’s Rule – Polar seal
Physiological adaptation – Kangaroo rat
Behavioural adaptation – Desert lizard
Biochemical adaptation – Marine fish at depth
