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

1. A typical plant cell is treated with enzymes that remove its wall. Its plasma membrane, nucleus, mitochondria and large vacuole remain intact, but the particular tissue examined contains no developed chloroplasts. Which conclusion is most justified?

2. A prokaryotic glycogen granule and a typical plant-cell vacuole can both contain stored material. The feature that most directly separates them is that:

3. A transverse section of a membrane-covered appendage shows nine peripheral doublets surrounding a bridged central pair. Structure P encloses the central pair, structures Q radiate outward from P, and structures R join adjacent peripheral doublets. P, Q and R are respectively:

4. Evaluate the following statements about cell-wall composition.
I. Some algal walls may contain cellulose, galactans, mannans and calcium carbonate.
II. Other plant walls may contain cellulose, hemicellulose, pectins and proteins.
III. The presence of cellulose means every algal and plant wall has the same composition.
IV. Calcium carbonate may contribute to the wall of certain algae.

5. A motile appendage is covered by plasma membrane and contains a microtubular axoneme. It must be:

6. A drug disrupts much of the cytoskeletal network while leaving the plasma membrane, ribosomes and mitochondria initially intact. Which combination of effects is most likely?

7. An external bacterial appendage has three labelled regions. P is a long projecting strand, Q is a short curved connector at its base, and R is embedded in the cell envelope. The correct identification is:

8. Evaluate the following statements about phospholipid orientation in the plasma membrane.
I. Polar heads face aqueous environments on both sides of the membrane.
II. Hydrocarbon tails are directed toward the interior of the bilayer.
III. Hydrophobic tails normally project freely into extracellular fluid and cytoplasm.
IV. The centre of the bilayer is predominantly non-polar.

9. A graph plots relative protein-synthesis activity on the horizontal axis and average nucleolar size on the vertical axis. Across comparable cells, nucleolar size rises as protein-synthesis activity increases. The most justified interpretation is:

10. A cell lacks a wall and plastids but contains centrioles, mitochondria, RER, Golgi apparatus and lysosomes. After vesicle budding from the ER is blocked, a labelled secretory protein accumulates in the RER and fails to appear at the Golgi cis face. The strongest combined interpretation is:

11. Contractile-vacuole activity is selectively stopped in a freshwater Amoeba, while its plasma membrane and food vacuoles remain functional. The most immediate expected effect is:

12. Use the arrangements described below. Cell P contains DNA in an unenclosed region and lacks membrane-bound organelles. Cell Q contains chromosomes inside a nuclear envelope and also has mitochondria and endoplasmic reticulum. The cells are respectively:

13. Assertion: Lysosomes and vacuoles are both included in the endomembrane system.
Reason: Lysosomal hydrolytic enzymes generally function optimally at acidic pH.

14. From the cytoplasmic side inward, membrane P is encountered first in a chloroplast envelope, narrow region Q lies between two membranes, membrane R directly encloses region S, and thylakoids occur within S. P, Q, R and S are respectively:

15. A mutation prevents coordinated beating of numerous short surface projections but leaves one long locomotory projection in another cell type unaffected. The function most directly reduced in the first cell type is:

16. Match each entry in Column I with the most closely associated contribution in Column II. A Column II entry is used once.

17. A non-dividing nucleus contains a diffuse thread-like material P, one or more dense spherical regions Q and a surrounding internal matrix R. P, Q and R are respectively:

18. Mitochondria are commonly called the powerhouses of the cell because they:

19. 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:

20. Two bacterial samples are subjected to Gram staining under identical conditions. Sample P retains the stain, whereas sample Q does not. They should be placed respectively in:

21. During nuclear-envelope formation, the outer and inner membranes remain parallel but fail to fuse at sites where pores should develop. Which consequence is most direct?

22. Consider the following statements.
I. Protists, plants, animals and fungi possess eukaryotic cellular organisation.
II. Their cells characteristically contain an organised nucleus and membrane-bound compartments.
III. Cell walls and plastids are not universal features of all four groups.
IV. Absence of plastids is sufficient to classify a cell as prokaryotic.

23. A Gram-positive population and a Gram-negative population both survive well in a dilute medium while their cell walls remain intact. Enzymatic wall removal greatly increases bursting in both populations, although their Gram responses remain different. The best conclusion is:

24. Four cell types are examined under comparable conditions.

The most appropriate interpretation is:

25. A transverse section of a membrane-covered eukaryotic appendage shows a bridged central pair surrounded by a sheath. Nine radial spokes extend from this sheath toward nine peripheral doublets, and neighbouring doublets are linked. The internal arrangement is:

26. Vesicular communication among the endoplasmic reticulum, Golgi apparatus, lysosomes and vacuoles is severely disrupted. Mitochondrial respiration and chloroplast photosynthetic organisation remain initially normal. This pattern is best explained by:

27. A mutation disables the carrier used by polar solute P. The plasma membrane remains intact, neutral solute Q still diffuses normally, and an unrelated ATP-dependent ion pump continues to function. The immediate prediction is:

28. The outer coating of a bacterium is loose and not organised into a thick, tough covering. It is described as a ______ rather than a capsule.

29. A protist surrounds a food particle with its cell surface. The particle then appears inside a newly formed membrane-bound compartment where digestion begins. The compartment is:

30. A cell image shows a membrane-bound compartment P. Inside P are several thread-like structures Q, and each Q contains hereditary material R. The most accurate identification is:

31. A bacterial strain loses a small circular DNA molecule and becomes antibiotic-sensitive, but its principal chromosome, nucleoid, plasma membrane and ribosomes remain unchanged. Which conclusion accounts for both observations?

32. The cell wall of an onion epidermal cell is selectively removed while its plasma membrane and internal components remain intact. The most direct structural consequence is:

33. Engulfment of food particles is experimentally blocked in Amoeba, but the contractile vacuole continues its regular filling and emptying cycle. The most likely observation is:

34. Four preparations are maintained under suitable conditions: an isolated nucleus, isolated mitochondria, free ribosomes and intact unicellular organisms. Only the intact cells grow and reproduce over successive generations. The strongest inference is that:

35. 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:

36. An impermeable fluorescent marker is added to the cytoplasm of cells containing intact ER. The marker remains outside the ER lumen. After detergent disrupts ER membranes, it enters the former luminal region. This experiment supports the conclusion that:

37. Two cylindrical structures are compared.

P and Q are most accurately identified as:

38. A membrane is experimentally formed around the principal chromosome of a bacterial cell, but the cell still lacks endoplasmic reticulum, Golgi apparatus, mitochondria and other eukaryotic structures. The most justified interpretation is that:

39. 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:

40. Which term names the centriole-like structure from which a eukaryotic cilium or flagellum emerges?

41. Flagella are removed from a bacterial population, but pili and fimbriae remain intact. Directional movement decreases greatly, while attachment to a solid surface remains measurable. The result indicates that:

42. The primary constriction and normal kinetochores of a chromosome remain intact, but a mutation removes its constant secondary constriction. The most direct expected change is:

43. Starting from the distal external portion of a bacterial flagellum and moving toward the cell envelope, the correct sequence is:

44. The transport records below refer to an intact plasma membrane.

The record that requires correction is:

45. An unknown cell possesses a membrane-bound nucleus, mitochondria, ER and Golgi apparatus. A rigid wall lies outside its plasma membrane, but plastids are absent. Which interpretation is most justified?

46. A bacterial cell contains several dense granules dispersed in its cytoplasm. Each granule stores reserve material, and no membrane separates it from the surrounding cytoplasmic matrix. These structures are best identified as:

47. Assertion: Cytoplasm is present in both prokaryotic and eukaryotic cells.
Reason: Only eukaryotic cytoplasm supports biochemical reactions required for the living state.

48. A viable cell has DNA, cytoplasm, ribosomes and a plasma membrane but lacks both a nuclear envelope and a cell wall. Its organisation is most consistent with:

49. Evaluate the following statements about endoplasmic-reticulum organisation.
I. It forms a network of tubules and cisternae.
II. Its membranes enclose a luminal compartment.
III. It separates luminal space from surrounding cytoplasm.
IV. Its lumen is continuous with the extracellular environment through permanent open pores.

50. The membrane of a thylakoid is ruptured, while the chloroplast envelope remains intact. The earliest expected result is: