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

1. A complete centriole has nine peripheral triplets. If each triplet contains three microtubules, the number of peripheral microtubules is:

2. A labelled polypeptide is synthesised normally on rough ER and reaches the Golgi apparatus. A treatment then inhibits Golgi modification enzymes without damaging ribosomes or ER transport vesicles. The most likely result is:

3. Which classification is correct?

4. Within a chromosome, primary constriction P holds the chromatids together. Farther along one arm, a constant non-staining constriction Q separates a small terminal segment R. Q and R are respectively:

5. Consider the following statements about eukaryotic cilia and flagella.
I. Cilia are usually shorter than flagella.
II. Cilia may move a cell or surrounding fluid.
III. Flagella chiefly propel the cell.
IV. Cilia and flagella have completely unrelated internal organisation.

6. Arrange the following contributions in chronological order.
P. Schleiden concluded that plants are composed of cells forming tissues in .
Q. Schwann proposed a cellular basis for plants and animals in .
R. Virchow stated that cells arise from pre-existing cells in .

7. The findings from two plasma-membrane investigations are summarised below.

The strongest conclusion from the combined evidence is:

8. Consider the following statements about mesosomes in prokaryotic cells.
I. They arise as infoldings of the plasma membrane.
II. They may occur as vesicles, tubules and lamellae.
III. They are associated with functions such as wall formation, DNA distribution, respiration and secretion.
IV. They are pigment-containing structures specialised only for photosynthesis.

9. Using the representative dimensions for Mycoplasma and for a human erythrocyte, the erythrocyte diameter is approximately:

10. Two populations of the same cell type have equal nuclear DNA content but differ in protein-synthesis activity.

The strongest interpretation of the observations is:

11. Two animal cells are observed before and after a treatment.

The treatment most directly affected the:

12. 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.

13. Representative dimensions are for PPLO, for viruses and for typical bacteria. Which inference uses these values appropriately?

14. 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:

15. 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:

16. 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:

17. Assertion: Mitochondria are excluded from the endomembrane system despite being membrane-bound organelles.
Reason: Mitochondria possess cristae formed by folds of their inner membrane.

18. Four records describe a typical human somatic cell.

The internally consistent record is:

19. 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.

20. A fungal cell contains chromosomes inside a nuclear envelope and possesses mitochondria, endoplasmic reticulum and Golgi apparatus, but it lacks plastids. The most accurate interpretation is:

21. A small cytoplasmic particle is shown as a larger component P associated with a smaller component Q. P has a sedimentation value of , Q has a value of , and the assembled particle translates messenger RNA. The assembled structure is:

22. Arrange the following events in the pathway of a newly synthesised secretory protein.
P. Translation on a ribosome attached to rough ER
Q. Entry into an ER-derived transport vesicle
R. Arrival at the Golgi cis face
S. Modification and movement toward the Golgi trans face
T. Delivery in a vesicle to the plasma membrane

23. Evaluate the following statements about lysosomes.
I. They are membrane-bound vesicles formed through Golgi packaging.
II. They contain hydrolytic enzymes such as lipases, proteases and carbohydrases.
III. Their hydrolytic enzymes generally function optimally under acidic conditions.
IV. Their principal role is synthesis of secretory proteins on attached ribosomes.

24. Which classification correctly separates endomembrane components, semiautonomous organelles, non-membranous structures and microbodies?

25. In two bacteria, an outer coating lies outside the cell wall, which in turn lies outside the plasma membrane. The coating is loose and unorganised in P but thick and tough in Q. The correct interpretation is:

26. A typical human somatic cell contains approximately of DNA distributed among chromosomes. If an arithmetic average is calculated, the DNA length per chromosome is closest to:

27. 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:

28. Consider the following statements about Theodor Schwann's contribution.
I. He described the plasma membrane in animal cells.
II. He recognised the cell wall as a distinctive feature of plant cells.
III. He proposed that plants and animals consist of cells and cellular products.
IV. He introduced the principle that all new cells arise from pre-existing cells.

29. Four bacterial records are compared.

The strongest synthesis is:

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

31. An erythrocyte retains its volume but loses much of its normal biconcave form and becomes nearly spherical. The most likely functional consequence is:

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

33. The hook of a bacterial flagellum is selectively damaged, while the filament and basal body remain present. The most likely consequence is:

34. Chromatophores, flagella and ribosomes remain intact in a bacterial cell, but damage to internal plasma-membrane infoldings is followed by defective wall formation, disturbed DNA distribution, reduced respiration and decreased secretion. The damaged structures are most likely:

35. Evaluate the following statements using the representative scale values.
I. Viruses may range from to .
II. PPLO may have a value near .
III. Overlapping dimensions make size alone insufficient for deciding cellular status.
IV. Viruses should be classified as the smallest cells.

36. A drug detaches all but one ribosome from each bacterial messenger RNA without degrading the messenger RNA or inhibiting the remaining ribosome. Which change is most likely?

37. Which chronological sequence is correct?

38. A mutation causes mitochondrial inner membranes to remain almost smooth while preserving the outer membrane, matrix enzymes and total mitochondrial number. The most direct expected effect is:

39. A botanist examines root, stem and leaf tissues from several plants. Although the cells differ in form and arrangement, every tissue is built from cellular units. The inference most closely aligned with Schleiden's work is that:

40. Assertion: The presence of a flagellum does not by itself establish whether a cell is prokaryotic or eukaryotic.
Reason: Prokaryotic and eukaryotic cells may both possess flagella, but their flagella differ fundamentally in structure.

41. Which pairing correctly identifies the principal chloroplast location of the stated component?

42. A graph plots total cellular protein-synthesis rate against time after nucleolar ribosomal-RNA synthesis is inhibited at . The curve remains near its original level briefly and then declines progressively. Which explanation best accounts for the delayed fall?

43. A treatment selectively destroys chlorophyll-containing thylakoid membranes while leaving most stroma enzymes initially active. Which immediate pattern is most likely?

44. 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:

45. Two microscopic entities are compared.

Which interpretation is most accurate?

46. Three unknown cells are compared.

The most accurate identification is:

47. 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:

48. Three colourless or coloured plastids are isolated from plant tissues.

P, Q and R are respectively:

49. 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:

50. Arrange the following events in the order expected as a cell enters division.
P. Chromatin exists as an extended nuclear network.
Q. Chromatin fibres begin to condense.
R. Condensation increases and individual structures become distinguishable.
S. Distinct chromosomes are visible during division.