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

1. Examine the following cellular records.

The record requiring correction is:

2. 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:

3. 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:

4. A plasma membrane is described as two phospholipid layers between extracellular fluid and cytoplasm. Region P touches extracellular fluid, region Q forms the centre of the bilayer, and region R touches cytoplasm. The appropriate arrangement is:

5. 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.

6. Evaluate the following statements about chromatophores.
I. They are pigment-containing membranous extensions.
II. They occur in certain photosynthetic prokaryotes, including cyanobacteria.
III. They are associated with photosynthetic activity.
IV. They are functionally identical to mesosomes in every prokaryotic cell.

7. Consider the following statements about Golgi function.
I. Proteins synthesised on RER-associated ribosomes may be modified in Golgi cisternae.
II. The Golgi apparatus is an important site for glycoprotein and glycolipid formation.
III. Translation of messenger RNA occurs mainly inside Golgi cisternae.
IV. Modified products may be packaged before leaving the trans face.

8. A human erythrocyte membrane contains approximately protein and lipid. Which numerical comparison is accurate?

9. Ribosomes attached to rough endoplasmic reticulum are experimentally detached, but free cytoplasmic ribosomes and ribosomes inside mitochondria remain undisturbed. The immediate distributional change is that:

10. Let represent a Mycoplasma cell, a bacterium within the common size range and a human erythrocyte. The representative scale relation is:

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

12. 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:

13. 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:

14. A minute intracellular vesicle is enclosed by a membrane and contains several enzymes. Similar structures occur in both plant and animal cells. It is best identified as a:

15. Four unknown cells are compared.

The internally consistent eukaryotic record is:

16. The records below concern mature cells.

Which set contains all the biologically consistent records?

17. An isolated mitochondrion can carry out some biochemical reactions for a limited period but cannot maintain independent living existence. This observation best supports the conclusion that:

18. 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:

19. In a scaled drawing, a perinuclear space of is represented by . Under the same scale, a measured space of , which lies within the stated range, should be represented by:

20. A cell diagram shows two short cylindrical structures near the nucleus. Cylinder P is viewed longitudinally, while cylinder Q is viewed in cross-section. Their long axes are perpendicular, and both lie within a diffuse surrounding region. The complete structure is:

21. Match each prokaryotic structure in Column I with its most appropriate relation in Column II. A Column II entry is used once.

22. Cell P is a photosynthetic bacterium with gas-filled inclusions that help it remain at a favourable depth. Cell Q is a protist with a membrane-bound food vacuole used during intracellular digestion. Which comparison is accurate?

23. Ribosomes are experimentally detached from rough ER without immediately destroying the ER membrane or its lumen. The earliest expected result is:

24. Match each observed disturbance in Column I with the mesosome-associated relation in Column II. A Column II entry is used once.

25. 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.

26. A cell fraction contains particles made of RNA and proteins. The particles synthesize polypeptides when supplied with messenger RNA, amino acids and suitable cellular factors, but no lipid membrane can be detected around them. They are:

27. 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:

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. A mitochondrion is described by four regions. P is its external boundary, Q lies between two membranes, R is the membrane folded into cristae, and S is the innermost compartment containing mitochondrial DNA. The correct identification is:

30. The semifluid cellular matrix that occurs in both prokaryotic and eukaryotic cells and supports numerous life-maintaining reactions is the:

31. A free ribosome in the cytoplasm of a eukaryotic cell becomes attached to rough endoplasmic reticulum and begins synthesising a polypeptide that enters the ER lumen. Which change is most accurately described?

32. A centriole near the plasma membrane becomes positioned at the base of a newly forming cilium and organises the appendage that extends outward. In this role, the centriole functions as a:

33. 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?

34. Consider the following statements about bacterial glycocalyx.
I. It occurs outside the cell wall.
II. It may form either a loose slime layer or a thick capsule.
III. Slime layer and capsule must always occur as two separate coverings on one cell.
IV. The terms slime layer and capsule depend on the organisation of the glycocalyx.

35. Consider the following statements about genetic organisation in a typical prokaryotic cell.
I. The principal genetic material is generally a single circular chromosome.
II. The chromosome occupies a region not bounded by a nuclear membrane.
III. Absence of a well-defined nucleus implies absence of DNA.
IV. The non-membrane-bound genetic region is called the nucleoid.

36. Match each structure in Column I with the most appropriate description in Column II. A Column II entry is used once.

37. A cell has a small central body, numerous short branches and one exceptionally long process extending toward distant cells. Its form is most consistent with:

38. 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?

39. Consider the following statements about secondary constrictions and satellites.
I. A secondary constriction is distinct from the primary centromere.
II. It may occur at a constant location on a chromosome.
III. It may separate a small chromosome segment called a satellite.
IV. The satellite is an independent whole chromosome with its own centromere.

40. 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:

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

42. 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.

43. From the exterior inward, a bacterium has a diffuse outer coating P, a rigid layer Q and a thin selectively permeable layer R immediately around the cytoplasm. If P alone is removed, the most accurate interpretation is:

44. Pigment-containing membranous extensions are selectively removed from a photosynthetic prokaryote, while mesosomes remain structurally intact. Photosynthetic product formation falls sharply, but wall formation remains nearly normal. The result most strongly supports the view that:

45. Arrange the following events in the developmental order expected for a plant cell that forms a secondary wall.
P. A primary wall surrounds the young growing cell.
Q. The cell enlarges while the primary wall remains capable of extension.
R. Growth declines as the cell matures.
S. Secondary wall material is deposited inside the primary wall toward the plasma membrane.

46. Examine the following plant-animal comparison records.

The record requiring correction is:

47. Preparation P contains one messenger RNA with six ribosomes attached. Preparation Q contains six messenger RNA molecules with one ribosome attached to each. All ribosomes are active. Which comparison is accurate?

48. 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:

49. Four bacterial records are compared.

The strongest synthesis is:

50. Assertion: Mature mammalian erythrocytes and mature sieve-tube elements may remain living even when they lack nuclei.
Reason: One nucleus per cell is a common arrangement in eukaryotic cells.