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100 questions in this collection · Page 1 of 10
Question 1 of 100
📘 CLASS XI
Excretory Products And Their Elimination
Analyze the following statements regarding nitrogenous waste excretion and animal habitats:
I. Ammonia is the most toxic nitrogenous waste and requires large amounts of water for its elimination. II. Uric acid is the least toxic nitrogenous waste and can be removed with minimum loss of water. III. Terrestrial adaptation necessitated the production of more toxic wastes like ammonia to conserve body water. IV. Bony fishes, terrestrial amphibians, and marine insects are typically ammonotelic in nature.
Explanation: Statements I and II are correct. Statement III is incorrect because terrestrial adaptation favored the production of less toxic nitrogenous wastes such as urea and uric acid to conserve water. Statement IV is incorrect because bony fishes, aquatic amphibians, and aquatic insects are ammonotelic, whereas terrestrial amphibians are ureotelic.
Question 2 of 100
📘 CLASS XI
Excretory Products And Their Elimination
Evaluate the statements below regarding excretory structures across different animal groups:
I. Protonephridia or flame cells are the primary excretory structures in Platyhelminthes (e.g., Planaria), rotifers, some annelids, and Amphioxus. II. Protonephridia are primarily concerned with nitrogenous waste excretion rather than fluid volume regulation. III. Malpighian tubules are the tubular excretory structures of earthworms that help in the removal of nitrogenous wastes. IV. Antennal glands or green glands perform the excretory function in crustaceans like prawns.
Explanation: Statements I and IV are correct. Statement II is incorrect because protonephridia mainly function in osmoregulation (ionic and fluid balance). Statement III is incorrect because earthworms possess nephridia, whereas Malpighian tubules are found in insects.
Question 3 of 100
📘 CLASS XI
Excretory Products And Their Elimination
Consider the following statements regarding the gross anatomy and location of the human kidney:
I. Kidneys are reddish-brown, bean-shaped structures situated between the levels of the last thoracic and third lumbar vertebrae. II. An adult human kidney measures 10–12 cm in length, 5–7 cm in width, and 2–3 cm in thickness. III. The average weight of an adult human kidney is 120–170 g. IV. Towards the centre of the outer convex surface is a notch called the hilum through which blood vessels enter.
Explanation: Statements I, II, and III are correct. Statement IV is incorrect because the hilum is present on the inner concave surface of the kidney, not on the outer convex surface.
Question 4 of 100
📘 CLASS XI
Excretory Products And Their Elimination
Analyze the following statements about the internal zones of the human kidney:
I. Inside the kidney, there are two distinct zones: an outer medulla and an inner cortex. II. The medulla is divided into a few conical masses called medullary pyramids projecting into the calyces. III. The cortex extends in between the medullary pyramids as renal columns of Bertini. IV. Inner to the hilum is a broad funnel-shaped space called the renal pelvis with projections called calyces.
Explanation: Statement I is incorrect because the outer region is the cortex and the inner region is the medulla. Statements II, III, and IV are correct.
Question 5 of 100
📘 CLASS XI
Excretory Products And Their Elimination
Regarding human nephrons and their distribution in the kidney, identify the correct statements:
I. Each kidney has nearly one million complex tubular structures called nephrons, which are the functional units. II. In the majority of nephrons, the loop of Henle is very long and runs deep into the medulla. III. Juxtamedullary nephrons have a very short loop of Henle that extends only very little into the medulla. IV. The Malpighian corpuscle, PCT, and DCT of the nephron are situated in the cortical region of the kidney.
Explanation: Statements I and IV are correct. Statement II is incorrect because most nephrons are cortical nephrons with short loops of Henle. Statement III is incorrect because juxtamedullary nephrons possess long loops of Henle extending deep into the medulla.
Question 6 of 100
📘 CLASS XI
Excretory Products And Their Elimination
Consider the following statements about renal vasculature and capillary networks:
I. The glomerulus is a tuft of capillaries formed by the efferent arteriole, which is a fine branch of the renal artery. II. Blood from the glomerulus is carried away by an efferent arteriole. III. The efferent arteriole emerging from the glomerulus forms a fine capillary network around the renal tubule called the peritubular capillaries. IV. Vasa recta is a U-shaped vessel parallel to the loop of Henle and is highly developed in cortical nephrons.
Explanation: Statements II and III are correct. Statement I is incorrect because the glomerulus is formed by the afferent arteriole. Statement IV is incorrect because vasa recta are highly developed in juxtamedullary nephrons, not cortical nephrons.
Question 7 of 100
📘 CLASS XI
Excretory Products And Their Elimination
Which of the following statements about the glomerular filtration membrane are true?
I. On average, 1100–1200 ml of blood is filtered by the kidneys per minute, constituting roughly 1/5th of the cardiac output of each ventricle. II. The filtration membrane consists of the endothelium of glomerular blood vessels, the basement membrane, and the epithelium of the renal pelvis. III. The epithelial cells of Bowman's capsule, called podocytes, are arranged in an intricate manner leaving minute spaces called filtration slits or slit pores. IV. All constituents of plasma including proteins pass easily into the lumen of the Bowman's capsule under high pressure.
Explanation: Statements I and III are correct. Statement II is incorrect because the filtration membrane includes the epithelium of Bowman's capsule, not the renal pelvis. Statement IV is incorrect because proteins are normally retained in the blood and do not pass into Bowman's capsule.
Question 8 of 100
📘 CLASS XI
Excretory Products And Their Elimination
Read the statements below regarding the Glomerular Filtration Rate (GFR) and the Juxtaglomerular Apparatus (JGA):
I. GFR in a healthy individual is approximately 125 ml/minute, which is about 180 litres per day. II. JGA is a special sensitive region formed by cellular modifications in the proximal convoluted tubule and the afferent arteriole. III. A fall in GFR can activate the JG cells to release renin. IV. Renin stimulates glomerular blood flow and thereby brings GFR back to normal.
Explanation: Statements I, III, and IV are correct. Statement II is incorrect because the juxtaglomerular apparatus (JGA) is formed by cellular modifications in the distal convoluted tubule (DCT) and the afferent arteriole, not the proximal convoluted tubule (PCT).
Question 9 of 100
📘 CLASS XI
Excretory Products And Their Elimination
Which of the following statements correctly describe the renal mechanisms of reabsorption and secretion?
I. Nearly 99 per cent of the filtrate has to be reabsorbed by the renal tubules to produce urine. II. Substances like glucose and amino acids are reabsorbed actively, whereas nitrogenous wastes are reabsorbed by passive transport. III. Reabsorption of water occurs actively in the initial segments of the nephron. IV. Tubular secretion of H+, K+, and ammonia helps in the maintenance of ionic and acid-base balance of body fluids.
Explanation: Statements I, II, and IV are correct. Statement III is incorrect because water is reabsorbed passively in the initial segments of the nephron.
Question 10 of 100
📘 CLASS XI
Excretory Products And Their Elimination
Consider these statements about the Proximal Convoluted Tubule (PCT):
I. PCT is lined by simple cuboidal brush border epithelium, which increases the surface area for reabsorption. II. Nearly all of the essential nutrients, and 70–80 per cent of electrolytes and water are reabsorbed by this segment. III. PCT maintains pH by selective secretion of hydrogen ions, ammonia, and bicarbonate ions into the filtrate. IV. PCT is capable of absorbing bicarbonate ions (HCO3-) from the filtrate.
Explanation: Statements I, II, and IV are correct. Statement III is incorrect because the PCT secretes H+ and ammonia into the filtrate but reabsorbs bicarbonate ions (HCO3-) rather than secreting them.