Excretory Products and Their Elimination Mock Test – Class 11 Biology

1. Isolated collecting ducts are tested under three conditions. In condition P, a strong medullary osmotic gradient and ADH are both present, and water leaves rapidly. In condition Q, the same gradient is present without effective ADH, and water movement is low. In condition R, ADH is present but the surrounding fluid has no osmotic gradient, and water movement is also low. What is the strongest conclusion?

2. Equal areas of skin are studied under identical temperature conditions. Area P has active sweat glands, while sweat glands in area Q are blocked. Sebaceous secretion remains normal in both. Area P shows greater evaporative water loss and releases traces of urea and lactic acid. The strongest inference is:

3. Assertion: Tubular secretion removes selected ions from filtrate and returns them to blood.
Reason: Tubular cells can add , and ammonia to filtrate, contributing to ionic and acid-base balance.

4. Arrange the principal stages in urea production and elimination in a ureotelic mammal.
P. Metabolic ammonia reaches the liver.
Q. The liver converts ammonia into urea.
R. Urea enters the blood.
S. The kidneys filter urea for excretion.
T. Urea leaves the body in urine.

5. An arthropod specimen is identified as an insect. It possesses tubular excretory structures whose failure disturbs both nitrogenous-waste elimination and osmoregulation. The structures are most likely:

6. Bladder filling activates stretch receptors, sensory signals reach the CNS, and the bladder and sphincter are capable of a normal motor response. A healthy adult voluntarily delays urination. Which event best explains the delay?

7. At one medullary level, filtrate in structure P moves downward, filtrate in structure Q moves upward, blood in structure R moves downward and blood in structure S moves upward. P and Q are adjacent loop limbs, while R and S are adjacent vasa-recta limbs. Their close arrangement principally supports:

8. Compare blood plasma with fluid collected normally from Bowman’s capsule.

Which conclusion follows from the complete pattern?

9. The volume of filtrate formed by both kidneys per unit time is termed ______.

10. Three labelled substances enter the afferent arteriole of a normal nephron.

Which conclusion follows from the complete table?

11. Consider the following statements.
I. A glomerulus together with Bowman’s capsule forms a Malpighian body.
II. Malpighian tubules are excretory and osmoregulatory structures of most insects.
III. A Malpighian body and a Malpighian tubule are identical structures occurring in the human kidney.
IV. Bowman’s capsule is part of the insect Malpighian-tubule system.

12. Assertion: Angiotensin II stimulates the adrenal medulla to release aldosterone.
Reason: Aldosterone released from the adrenal cortex increases distal and water reabsorption.

13. Match each physiological failure with the waste most likely to accumulate first. Each Column II entry is used once.

14. An unknown animal lives in a dry habitat, eliminates a semisolid nitrogenous product and possesses Malpighian tubules that also contribute to osmoregulation. It is best classified as:

15. Air entering and leaving the lungs is compared under controlled conditions. Exhaled air produces a stronger carbon-dioxide indicator response, and water condenses on a cooled surface placed in the outgoing air stream. Which inference is most strongly supported?

16. Match each urine-formation process with the principal direction of movement. Each Column II entry is used once.

17. A graph has daily fluid volume on the vertical axis. Three bars represent renal blood delivered, glomerular filtrate formed and final urine excreted. Their approximate heights are , and , respectively. Which conclusion best explains the pattern?

18. Arrange the filtration structures in the order crossed by fluid moving from glomerular blood into Bowman’s lumen.
P. Epithelium of Bowman’s capsule
Q. Basement membrane
R. Glomerular endothelium

19. A solute is handled by one nephron as follows: units are filtered, units are reabsorbed and additional units are secreted into the tubule. How many units are excreted, and what does the result show?

20. A tubule begins at a double-walled capsule, continues through a highly coiled segment, descends and ascends as a loop, and then forms another coiled segment. The final coiled segment is:

21. Two nephron records are compared.

Nephrons P and Q are respectively:

22. Kidney malfunction sharply reduces the removal of urea from blood. Which change is most directly predicted?

23. Assertion: Diabetes insipidus is defined by glucose appearing in urine due to deficient insulin action.
Reason: Deficient ADH action can cause excessive production of dilute urine without glycosuria being the defining feature.

24. In preparation P, ascending-limb transport is blocked. In preparation Q, urea movement from medullary collecting ducts into the interstitium is blocked. Both preparations show reduced inner-medullary osmolarity. Which conclusion is best supported?

25. At the renal hilum, the renal artery, renal vein and ureter connect the kidney with the circulation and urinary tract. Which directional pattern is correct?

26. The movements recorded in two limbs of a minute medullary blood vessel are shown below.

Segments P and Q are respectively:

27. Nephron P has a short loop that enters the medulla only slightly. Nephron Q has a long loop reaching deep into the medulla. Which vascular comparison is expected?

28. In one nephron, PCT transport is normal, the descending limb has lost water permeability, the ascending limb still transports electrolytes, and the DCT remains responsive to regulation. Which downstream change is most likely?

29. Daily filtrate remains , but impaired tubular water recovery raises urine output to . What percentage of the filtrate is reabsorbed?

30. Arrange the events that describe the collecting-duct contribution of urea to urine concentration. P. A small amount of urea leaves medullary collecting-duct fluid. Q. Urea enters the medullary interstitium. R. Medullary osmolarity is supported. S. Water movement out of a permeable collecting duct is favoured.

31. Evaluate the following statements about the columns of Bertini.
I. They are extensions of cortical tissue.
II. They occur between medullary pyramids.
III. They are also called renal columns.
IV. They form the funnel-shaped chamber that continues into the ureter.

32. A tubular organ removes urea from body fluids while also adjusting the quantities of water and ions returned to the body. This organ is performing:

33. Arrange the events involved in ADH-mediated water conservation after excessive water loss.
P. Effective body-fluid osmolarity rises and osmoreceptor signalling increases.
Q. Hypothalamic control promotes ADH release from the neurohypophysis.
R. Water reabsorption from later tubular regions and collecting ducts increases.
S. Urine volume decreases and urine becomes more concentrated.

34. Select the directional relations that correctly combine renal blood flow and urine transport.

35. Renal calculi are best described as:

36. A functioning kidney obtained from a donor is surgically placed in a patient with severe renal failure. The procedure is:

37. Use the arrangement described below. A segment of the DCT bends close to the afferent arteriole of the same nephron. Cellular modifications occur in both structures at their contact. This specialised region is the:

38. Arrange the structures in the route followed by urine from its site of formation to the exterior.
P. Urinary bladder
Q. Urethra
R. Kidney
S. Ureter

39. Two patients show the following renal findings.

Which mechanism best distinguishes the reduced urine flow in P and Q?

40. An arthropod is identified as a crustacean rather than an insect. Its characteristic excretory structure is expected to be ______ rather than ______.

41. Stretch receptors in the bladder wall are selectively blocked in an experimental preparation. The bladder fills normally, its muscles and sphincter can still respond to direct stimulation, and no voluntary emptying signal is given. The most likely result is:

42. In a longitudinal kidney section, band P lies between two conical medullary pyramids. Tissue sampling shows that P is continuous with the outer renal zone. Structure P is best classified as:

43. Glomerular filtration remains normal, but proximal tubular glucose reabsorption becomes severely impaired. Blood glucose is not otherwise changed. Which urinary change is predicted most directly?

44. An unknown aquatic vertebrate releases nitrogenous waste mainly as ammonium ions across its gills, uses its kidneys only minimally for this waste, and has continuous access to abundant water. It is best classified as ______ since its route permits ______.

45. Over many generations, an aquatic animal lineage colonises a habitat where free water is scarce. A shift in the dominant nitrogenous waste from ammonia toward uric acid would be favoured mainly as it:

46. Arrange the structures in the direction followed by blood through the glomerular vascular arrangement.
P. Efferent arteriole
Q. Glomerular capillary tuft
R. Afferent arteriole

47. A person has a normal corticomedullary osmotic gradient and normal glomerular filtration, but effective ADH action is severely deficient. A large volume of dilute urine is produced, and body-water loss increases. The primary defect is:

48. Consider the following statements.
I. Excretion includes elimination of metabolic wastes.
II. Egestion removes undigested material from the alimentary canal.
III. Removal of excess water or ions may contribute to internal balance.
IV. Every excretory product is nitrogenous.

49. Severe blood loss lowers renal perfusion and GFR. The juxtaglomerular apparatus remains functional, and the adrenal cortex responds normally. The coordinated response most likely to support restoration is:

50. Use the arrangement described below. Vessel P carries blood into capillary tuft Q enclosed by a cup-shaped structure. Vessel R carries blood away from Q and then forms network S around the renal tubule; in long-loop nephrons, part of this network forms U-shaped vessels beside the loop. Which interpretation is correct?