Title Ex-3 excretory Products and their (Solution file).docx.pdf ✅

40 EXCRETORY PRODUCTS AND THEIR ELIMINATION EXERCISE – 3: Achiever’s Section Modes of Excretion, Other Nitrogenous Wastes 1. Find out the name of the following. A. An animal having flame cells as excretory structure. B. Cortical portions projecting between the medullary pyramids in the human kidney. C. A loop of capillary running parallel to the Henle’s loop (a) (A)-Planaria, (B)-Duct of Bellini, (C)-Peritubular capillary (b) (A)-Amphioxus, (B)-Collecting duct, (C)-Vasrecta (c) (A)-Planaria, (B)-columns of Bertini, (C)-Vasa recta (d) (A)-Amphioxus, (B)-Columns of Bertini, (C) Peritubular capillary Ans. (c) Sol. Planaria is an animal having flame cells as their excretory structure. The columns of Bertini are the cortical portions projecting between the medullary pyramids in the human kidney. Vasa recta is a loop of the capillary that runs parallel to the loop of Henle. 2. The characteristic(s) common to urea, uric and ammonia is/are (i) They are nitrogenous wastes. (ii)They all need very large amount of water for excretion. (iii) They are all equally toxic. (iv) They are produced in the kidneys. (a) (i), (iii) and (iv) (b) (i) only (c) (i) and (iii) (d) (i) and (iv) Ans. (b) Sol. Urea, uric acid and ammonia are all nitrogenous wastes produced during metabolism. Ammonia is water-soluble as well as highly poisonous. Urea is less toxic than ammonia and requires less water for its excretion. Uric acid is the least poisonous and is least soluble in water compared to ammonia and urea. Kidney does not produce them. 3. Which one of the following options gives the correct categorization of animals according to the type of nitrogenous waste they give out? Ammonotelic Ureotelic Uricotelic (a) Pigeon, humans Aquatic amphibian, lizards Cockroach, frog (b) Frog, lizards Aquatic amphibian, humans Cockroach, pigeon (c) Aquatic animals Frog, terrestrial amphibians, Humans Pigeon, lizards, cockroach (d) Aquatic animals Cockroach, terrestrial amphibians, humans Frog, pigeon, lizards, Ans. (c) Sol. Ammonotelic animals are most of the aquatic animals that excrete ammonia as their nitrogenous waste. Ammonia is water-soluble and require a large quantity of water for its excretion. e.g., fishes, protozoans, etc. Ureotelic animals are the animals that excrete nitrogenous waste in the form of urea. Urea is less toxic than ammonia and requires less water for its excretion. e.g., some bony fishes, mammals, etc. Animals that excrete nitrogenous waste in the form of uric acid are known as uricotelic animals. Uric acid is the least poisonous and requires least water for its excretion than urea and ammonia. e.g., most terrestrial animals and birds. 4. Which one of the following statements is incorrect? (a) Birds and land snails are uricotelic animals (b) Mammals and frogs are ureotelic animals (c) Aquatic amphibians and aquatic insects are ammonotelic animals (d) Birds and reptiles are ureotelic. Ans. (d) Sol. Species that excrete nitrogenous waste substances in the form of urea are called ureotelic. It requires less water than ammonia. e.g., ureotelic animals are bony fishes (few), adult amphibians and mammals including humans. The birds and reptiles are uricotelic animals as they excrete uric acid instead of urea. 5. Read the following statements and find out the incorrect statement.
41 EXCRETORY PRODUCTS AND THEIR ELIMINATION A. Kidney plays very significant role in the removal of NH3 . B. Terrestrial adaptation necessitated the production of more toxic nitrogenous wastes like urea and uric acid for conservation of water. C. Some amount of urea may be retained in the kidney matrix of some of the ureotelic animals to maintain a desired osmolarity. D. Uricotelic animals excrete nitrogenous wastes as uric acid in the form of pellet of paste with a minimum loss of water. (a) A and B (b) B and C (c) C and D (d) A and D Ans. (a) Sol. The kidney does not play any significant role in the removal of ammonia because ammonia produced by metabolism is converted into urea in the liver of the animals and released into the blood which is filtered and excreted out by the kidneys. So, statement A is incorrect and statement B is also incorrect because urea and uric acid are less toxic than ammonia. Human Excretory System 6. What is wrong about kidney? (a) Peripheral cortex and central medulla (b) Blood enters glomerulus through efferent arterioles (c) Malpighian capsules occur in cortex (d) Concave part of kidney is called hilum Ans. (b) Sol. The afferent arterioles deliver blood to the glomerulus while the efferent arteriole carries blood out of the glomerulus. So, the statement in option (b) is incorrect. 7. Which one of the following statements is incorrect? (a) The medullary zone of kidney is divided into a few conical masses called medullary pyramids projecting into the calyces. (b) Inside the kidney, the cortical region extends in between the medullary pyramids as renal pelvis. (c) Glomerulus along with Bowman’s capsule is called the renal corpuscle. (d) Renal corpuscle, proximal convoluted tubule (PCT) and distal convoluted tubule (DCT) of the nephron are situated in the cortical region of kidney Ans. (b) Sol. Statement in option (b) is incorrect because inside the kidney, the cortical region extends in between the medullary pyramids is called renal column, not renal pelvis. Renal pelvis is a place at which two or three major calyces join together while the renal column is a medullary extension of the renal cortex in between the renal pyramids. 8. Recognise the figure and find out the correct matching. (a) f-Pelvis, e-Adrenal gland, a-Dorsal aorta, b-Renal artery, c-Inferior vena cava, d-renal vein (b) e-Pelvis, f-Adrenal gland, c-Dorsal aorta, a-Renal artery, d-Inferior vena cava, b-Renal vein (c) f-Pelvis, e-Adrenal gland, d-Dorsal aorta, a-Renal artery, c-Inferior vena cava, b-Renal vein (d) e-Pelvis, f-Adrenal gland, b-Dorsal aorta, d-Renal artery, a-Inferior vena cava, c-Renal vein. Ans. (c)
42 EXCRETORY PRODUCTS AND THEIR ELIMINATION Sol. As shown in the diagram: a-renal artery, b-renal vein, c-inferior vena cava, d-dorsal aorta, e-adrenal gland, f-pelvis. The renal artery carries blood from the heart to the kidneys. The renal vein carries blood filtered by the kidney. The inferior vena cava carries deoxygenated blood and the dorsal aorta carries oxygenated blood. The adrenal gland is present on the top of each kidney and the pelvis is the funnel-shaped structure which collects the urine produced in the nephrons of kidney. Urine Formation 9. Match the terms given in column I with their physiological processes given in column II and choose the correct answer. Column I Column II a. Proximal convoluted tubule i. Formation of concentrated urine b. Distal convoluted tubule ii. Filtration of blood c. Henle’s loop iii. Reabsorption of 70-80% of electrolytes d. Counter-current mechanism iv. Ionic balance e. Renal corpuscle in medulla v. Maintenance of concentration gradient (a) a-iii, b-v, c-iv, d-ii, e-i (b) a-iii, b-iv, c-i, d-v, e-ii (c) a-i, b-iii, c-ii, d-v, e-iv (d) a-iii, b-i, c-iv, d-v, e-ii Ans. (b) Sol. PCT is lined by simple cuboidal brush border epithelium which reabsorbs 70-80% of water and electrolytes. Distal convoluted tubules maintain the pH and ionic balance of the blood by reabsorption and selective tubular secretion. The main function of the loop of Henle is to reabsorb water and NaCl from the filtrate and conserves water by producing concentrated urine. A counter-current mechanism is used to maintain the concentration gradient of urine in the kidney by nephrons. Renal corpuscles are blood filtering components of the nephrons of the kidney. 10. Read the following statements and find out the incorrect statement. A. During urine formation, the tubular cells secrete substances like H + , K + and HCO3 – into the filtrate. B. As glomerular filtrate move down in descending limb of Henle’s loop, it gets concentrated and as concentrated filtrate pass upward in ascending limb of Henle’s loop, it gets diluted. C. Conditional reabsorption of Na + and water takes place in PCT. D. Reabsorption in ascending limb of Henle’s loop is minimum. (a) A and B (b) B and C (c) C and D (d) A and C Ans. (d) Sol. During urine formation, the tubular cells secrete substances like H + , K + and NH3 into the filtrate that helps in acid-base balance in the body while HCO3 – is reabsorbed in PCT. Conditional reabsorption of Na + and water takes place in the PCT.
43 EXCRETORY PRODUCTS AND THEIR ELIMINATION 11. Recognise the figure and find out the correct matching. (a) b–H + , d–H2O, c–Urea, a–NaCl, e–HCO3 – (b) c–H + , b–H2O, d–Urea, e–NaCl, a–HCO3 – (c) d–H + , b–H2O, e–Urea, c–NaCl, a–HCO3 – (d) a–H + , c–H2O, b–Urea, d–NaCl, e–HCO3 – Ans. (c) Sol. As shown in the figure, a–HCO3 – b–H2O, c–NaCl, d–H + , e–Urea. Main transportations through the loop of Henle are reabsorption of HCO3 – and water from the distal convoluted tubule along with the secretion of NaCl from PCT and ascending limb of the loop of Henle. H + are reabsorbed in the PCT and DCT. A little amount of urea enters the ascending limb of Henle's loop which is transported back to interstitium by collecting tubule. 12. Recognise the figure and find out the correct matching. (a) a–H2O, b–Urea, c-NaCl (b) c–H2O, a–Urea, b-NaCl (c) b–H2O, c–Urea, a-NaCl