Cell: The Unit of Life Mock Test – Class 11 Biology

1. A graph plots relative cellular-process rate on the vertical axis against decreasing membrane fluidity on the horizontal axis. Secretion, intercellular-junction formation and cell division all decline as fluidity becomes severely reduced. The pattern is best interpreted as evidence that:

2. Starting in the cytoplasm and moving directly into the nucleoplasm across an intact region of nuclear envelope that is not a pore, which sequence is correct?

3. Gas vacuoles are selectively disrupted in an aquatic photosynthetic bacterium, while its pigments, ribosomes and plasma membrane remain functional. The most likely immediate consequence is:

4. Assertion: The middle lamella helps bind neighbouring plant cells together.
Reason: A secondary wall is deposited inside the primary wall toward the plasma membrane.

5. Stroma lamellae are selectively disrupted while the individual grana remain structurally intact. The most direct architectural consequence is:

6. Assertion: Schleiden's conclusion connected the diversity of plant cells with the cellular organisation of plant tissues.
Reason: Repeated observations of many plants supported a generalisation that plant bodies are composed of cells.

7. Assertion: A centromere and a kinetochore should not be treated as two names for the same chromosome structure.
Reason: The centromere is the primary constriction, whereas disc-shaped kinetochores occur on its sides.

8. A graph plots relative membrane-transport rate on the vertical axis against time on the horizontal axis. At time , ATP synthesis is inhibited. Curve P remains nearly constant after , whereas curve Q rapidly falls toward zero. Before , both substances were moving across intact membranes. The most appropriate interpretation is:

9. A membrane surrounding a nucleus bears ribosomes on its cytoplasmic surface and is continuous with a ribosome-bearing endoplasmic-reticulum cisterna. The membrane is most likely the:

10. Study the analytical record below.

No other cell membrane was analysed. Which report is scientifically justified?

11. Plasmodesmata between two living plant cells are selectively blocked. The plasma membranes, primary walls and middle lamella remain intact. The most immediate expected effect is:

12. In a mature plant cell, layer P is an older outer wall that was present while the cell enlarged. Layer Q was deposited later between P and the plasma membrane and contributes additional strength. P and Q are:

13. A drug selectively blocks mitochondrial ribosomes but does not inhibit eukaryotic cytoplasmic ribosomes. The earliest direct effect is:

14. A polar solute is more concentrated outside a cell than inside. It cannot cross purified phospholipid bilayers, but it enters intact cells through a specific membrane carrier even when ATP production is inhibited. The movement is:

15. Which chronological sequence is correct?

16. Match each chromosome feature in Column I with the appropriate description in Column II. A Column II entry is used once.

17. In a bacterial flagellum, the longest part projecting from the cell surface is the ______, which is connected through a hook to the basal body.

18. Chemical analyses of two membranes give the following results.

Which conclusion is best supported?

19. Examine the following changed-condition records.

Which combination contains all biologically consistent records?

20. Four records describe a typical human somatic cell.

The internally consistent record is:

21. The tonoplast of a plant cell is selectively ruptured while the plasma membrane remains intact. The earliest expected result is:

22. Labelled ER-derived vesicles are followed near a Golgi stack. They first fuse with convex face P. Hours later, labelled products leave from concave face Q. When fusion at P is blocked, vesicles accumulate outside P and output from Q declines. The experiment identifies:

23. Consider the following statements about the fluid mosaic model.
I. Singer and Nicolson proposed the model in .
II. The lipid bilayer is quasi-fluid rather than a permanently rigid sheet.
III. All membrane proteins remain fixed at one position throughout the life of the cell.
IV. Different proteins distributed within or on the bilayer produce a mosaic appearance.

24. In a transverse section of a typical eukaryotic cilium, the axoneme contains:

25. Four membrane movements are listed below.

The most accurate evaluation is:

26. Match each axonemal component in Column I with its relation in Column II. A Column II entry is used once.

27. Assertion: The values protein and lipid should not be treated as exact universal values for every plasma membrane.
Reason: Membrane composition is identical in all cell types regardless of their specialised functions.

28. An unknown intracellular structure extends throughout the cytoplasm, is composed of several protein filament systems and has no single surrounding membrane. It is best classified as:

29. An unknown eukaryotic cell lacks a cell wall and plastids but contains a centrosome with two perpendicular centrioles near the nucleus. The most reasonable classification is:

30. In an erythrocyte membrane analysis, protein accounts for and lipid for of the measured mass. The unassigned portion is:

31. The set containing only representatives of prokaryotic cellular organisation is:

32. Arrange the chromosome types from a centromere in the middle toward a centromere at the terminal end.
P. Acrocentric
Q. Telocentric
R. Metacentric
S. Submetacentric

33. A graph plots photosynthetic light-energy capture on the vertical axis against total thylakoid-membrane area on the horizontal axis. Chlorophyll content per chloroplast remains constant, but light-energy capture declines as total membrane area is progressively reduced. The strongest inference is:

34. Oxygen concentration is initially higher outside a cell than inside it. Oxygen enters through the lipid region of the membrane until the difference is greatly reduced, even when cellular ATP production is temporarily blocked. The process is:

35. Match each vacuolar structure in Column I with its most appropriate role in Column II. A Column II entry is used once.

36. Two chambers contain pure water and a sugar solution. With a membrane permeable only to water, the liquid level rises on the sugar-solution side. When the membrane is replaced by a freely porous barrier that allows both water and sugar to mix, the distinct level change is not maintained. The result supports the conclusion that:

37. Schleiden and Schwann worked mainly from different organismal evidence, yet their conclusions converged on the relation that:

38. Near one end of a chromosome lies a primary constriction. A tiny arm extends beyond the constriction, while a much longer arm extends in the opposite direction. The chromosome is:

39. Match each bacterial shape with its corresponding term. A Column II entry is used once.

40. Cell P has a rigid wall outside its plasma membrane, several plastids and a vacuole occupying most of the central region. Cell Q has no wall or plastids but contains a centriole pair near its nucleus. The most accurate interpretation is:

41. A bacterial flagellum retains its basal body and hook, but its long external filament is removed. Which outcome is most directly expected?

42. A cell surface contains an outer rigid layer P and an inner flexible layer Q. A large undesirable macromolecule is restricted at P, while selective entry of a smaller solute is regulated at Q. The correct interpretation is:

43. Human erythrocytes are lysed, and their plasma membranes are isolated with little contamination from internal membranes. Chemical analysis of the preparation is intended primarily to determine:

44. Match each chromosome feature in Column I with its description in Column II. A Column II entry is used once.

45. A preparation contains Chlamydomonas cells with one chloroplast each and mesophyll cells with chloroplasts each. Which statement correctly combines the total count with the contribution of the mesophyll cells?

46. Assertion: Virchow's principle completed an important gap in the cell theory formulated from Schleiden's and Schwann's observations.
Reason: Virchow stated that new cells arise through division from pre-existing cells.

47. Match each chloroplast component in Column I with its principal location or relation in Column II. A Column II entry is used once.

48. From outside inward, the envelope of a bacterium consists of P, Q and R. P may be loose or capsular, Q is rigid, and R directly surrounds the cytoplasm. Movement of a test solute into the cytoplasm is regulated mainly at:

49. Two mitochondrial preparations are compared.

The strongest inference is:

50. Assertion: A chromosome satellite should be counted as a separate complete chromosome.
Reason: A satellite is a small chromosome segment separated from the main region by a secondary constriction.