Excretory Products and Their Elimination Mock Test – Class 11 Biology

1. In an experiment, protonephridia are selectively disrupted in an animal. Nitrogenous waste continues to leave through another route, but body-fluid volume and ion concentrations become unstable. The observation most strongly supports the conclusion that protonephridia:

2. A person produces urine at an average rate of for . Which daily volume and interpretation are accurate?

3. A person with renal failure continues eliminating through the lungs but has a high blood urea concentration. Blood is passed through a correctly functioning haemodialysis tube surrounded by plasma-like fluid without nitrogenous wastes. Which paired movement is expected?

4. Inside a kidney, a broad funnel-shaped chamber lies immediately internal to the hilum. It gives rise to cup-like projections that receive urine from conical medullary regions. The chamber and its projections are respectively:

5. Evaluate the following statements about normal urea excretion.
I. Approximately of urea may be eliminated per day.
II. Urea is a nitrogenous waste carried to the kidneys in blood.
III. Daily urea loss is distinct from total urine volume.
IV. Normal kidneys retain all produced urea permanently in the blood.

6. Consider the following statements about the human urinary system.
I. It contains two kidneys.
II. Each kidney is connected to the urinary bladder by a ureter.
III. The urinary bladder is an unpaired storage organ.
IV. Two urethrae normally carry urine from the bladder to the exterior.

7. Use the vasa-recta pathway described below. Blood enters near the cortex, descends into progressively hyperosmotic medulla, turns at a hairpin bend and then ascends toward the cortex. At which location is blood expected to have lost the most water and gained the most and urea relative to its entry state?

8. During an attempted micturition response, bladder smooth muscle contracts strongly but the urethral sphincter fails to relax. Which immediate outcome is most likely?

9. Four organ-secreted-fluid relationships are shown.

Which record is internally consistent?

10. A solute enters Bowman’s capsule during filtration. Half is returned to blood along the tubule, while additional molecules of the same solute are later added from blood into tubular fluid. The two tubular processes are:

11. The U-shaped vasa recta are replaced experimentally by rapidly flowing straight capillaries that carry blood directly from the cortex through the medulla and out again without counter-current exchange. The most likely consequence is:

12. 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:

13. A tracer crosses the glomerular capillary endothelium but is retained before it can reach the podocyte filtration slits. Which component of the filtration barrier most directly accounts for its retention?

14. The afferent arteriole supplying one nephron is completely blocked. The efferent arteriole and its downstream vessels remain structurally intact but receive no alternative blood supply. Which paired effect is expected?

15. Atrial tissue is stretched experimentally while renal perfusion, plasma osmolarity and ADH remain unchanged. The released factor dilates blood vessels and suppresses renin-related effects. Which inference is most strongly supported?

16. Two renal lesions are compared.

Which classification is correct?

17. Assertion: Every ureotelic animal immediately eliminates all urea produced in its body.
Reason: In some ureotelic animals, part of the urea is retained in the kidney matrix to help maintain a desired osmolarity.

18. An animal possesses antennal glands as its principal excretory structures. This evidence most strongly supports its placement among:

19. Match each segment with the transport pattern that most accurately characterises it. Each Column II entry is used once.

20. A small nitrogenous waste is passively reabsorbed from tubular fluid into peritubular blood. Its concentration is experimentally made equal on the two sides of the tubular wall, while membrane permeability and cellular ATP remain normal. What is the most likely immediate effect?

21. Podocyte filtration slits are damaged, and the JGA contact between the DCT and afferent arteriole is also destroyed. Glomerular pressure later falls. Which paired finding is most likely?

22. PCT cells remain alive and their blood supply is normal, but most brush-border projections are experimentally removed. All other nephron segments are unchanged. The most direct effect is:

23. Compare the renal disorders below.

Which interpretation is correct?

24. Use the arrangement described below. A nephron tubule leaves Bowman’s capsule, forms a loop and returns to the cortex. Near its own renal corpuscle, region P of the returning tubule closely contacts vessel Q entering the glomerulus. Cells in both structures are modified and form a sensitive regulatory region. Which identification is correct?

25. A needle is advanced from the outer surface of a kidney toward a calyx through the centre of a medullary pyramid. Which sequence of regions is encountered?

26. 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?

27. In an experimental nephron, the permeability of both loop limbs is normal, but flow through the ascending limb is artificially redirected so that it moves in the same direction as flow through the descending limb. The medullary osmotic gradient becomes much weaker. The result most strongly indicates that:

28. Four patients are assessed.

Which set contains the supported interpretations?

29. Consider the following statements about the PCT.
I. Its lining is simple cuboidal epithelium.
II. Its epithelial cells possess a brush border.
III. The brush border reduces the surface available for transport.
IV. The segment performs extensive reabsorption.

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

31. An unknown segmented invertebrate has numerous tubular organs. When these organs are blocked, nitrogenous waste accumulates and body-fluid ion concentrations become unstable. The animal does not possess Malpighian tubules or antennal glands. Which identification best fits the complete case?

32. Compare two nephron-associated vessels.

Vessels P and Q are respectively:

33. Consider the following statements about micturition.
I. Bladder filling activates stretch receptors.
II. Sensory signals are transmitted to the central nervous system.
III. A healthy adult can exert voluntary influence over initiation of urine release.
IV. The process is entirely independent of reflex organisation.

34. Renal blood flow is , while GFR is . During , the respective volumes delivered as blood and formed as filtrate are:

35. Consider the following statements about protonephridia.
I. They are also called flame cells.
II. They occur in Planaria and rotifers.
III. They are present in some annelids and Amphioxus.
IV. They are the characteristic excretory structures of most insects.

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

37. A fluid-filled chamber surrounds a long coiled porous tube carrying anticoagulated blood. The surrounding fluid resembles plasma but contains no nitrogenous wastes. This chamber and tube together function primarily to:

38. Daily urea excretion remains while urine volume rises from to . Assuming uniform mixing, how does the average urea concentration change?

39. Three unknown vertebrates are compared.

Which classification correctly integrates all four columns?

40. Match each sweat component with the relationship that best identifies it. Each Column II entry is used once.

41. A graph plots the rate of urea diffusion from blood to dialysate on the vertical axis and dialysis time on the horizontal axis. The rate declines gradually. At time , the used dialysate is replaced with fresh urea-free fluid, and the rate rises sharply. What explains this pattern?

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

Which conclusion follows from the complete pattern?

43. Formation of angiotensin II remains normal, and it continues to stimulate aldosterone release, but its vasoconstrictor action is selectively blocked. After a fall in GFR, the expected response is:

44. Use the section described below. Region P is the renal cortex and region Q is the medulla. Structures I, II and III are respectively a renal corpuscle, a DCT and the deep part of a loop of Henle. Their expected locations are:

45. An experimental injury makes the entire glomerular filtration barrier abnormally permeable. Filtrate collected from Bowman’s capsule now contains plasma proteins and blood cells that were absent before injury. The strongest conclusion is:

46. Evaluate the following statements about nephridia.
I. They are tubular excretory structures.
II. They occur in earthworms and other annelids.
III. They participate in nitrogenous-waste removal and fluid-ion balance.
IV. They are specialised exclusively for carbon-dioxide elimination.

47. Consider the following statements about Bowman’s capsule.
I. It is double walled.
II. It is cup shaped.
III. It encloses the glomerulus.
IV. It forms the beginning of the renal tubule.

48. Let represent GFR, renin activity, blood urea concentration and effective dialysis. Which relation best represents severe renal filtration failure followed by successful dialysis?

49. Use the arrangement described below. Specialised epithelial cells cover the outer surface of glomerular capillaries. Their interdigitating processes leave minute spaces through which filtrate passes before entering Bowman’s lumen. The cells and spaces are respectively:

50. Preparation P contains an intact glomerulus enclosed by Bowman’s capsule. In preparation Q, the capsule has been removed while glomerular blood flow remains. Which immediate difference is expected?