Cell Cycle and Cell Division Mock Test – Class 11 Biology

1. Consider the following statements about the normal products of telophase II and cytokinesis.
I. Four haploid cells are ordinarily formed.
II. Each product contains DNA.
III. Each chromosome in a final product consists of one chromatid.
IV. Homologous chromosomes undergo synapsis again in every product.

2. A species has . One meiocyte contains replicated chromosomes immediately before meiosis I. After normal completion of meiosis II, the summed chromosome count across all four products and the total DNA across those products are:

3. A population of adult tissue cells shows normal respiration and protein synthesis but no increase in cell number. After neighbouring cells are lost, the population begins DNA replication and division. The original state of these cells was most consistent with:

4. Two meiocytes show the following features.

The transition from Cell P to Cell Q most directly represents:

5. One mitotic cell completes chromosome segregation and forms two daughter nuclei, but cytokinesis fails. Separately, one meiocyte completes meiosis I with cytokinesis, and both resulting cells complete telophase II, but cytokinesis II fails in each. Across both systems, the final numbers of nuclei and cytoplasmic compartments are:

6. Arrange the following events in their normal cell-cycle order in an animal cell.
P. Many cellular constituents and organelles increase while nuclear DNA remains .
Q. Nuclear DNA reaches , and centrioles have duplicated in the cytoplasm.
R. Growth continues and proteins required for mitosis are synthesised.
S. Duplicated centrosomal regions move apart and the mitotic apparatus develops.

7. A treatment blocks centriole duplication during S phase in an animal cell but does not interfere with nuclear DNA replication. Which outcome is most reasonable?

8. Arrange the following events in their most defensible broad order during a normal M phase.
P. Nuclear division begins.
Q. Duplicated chromosome sets are segregated.
R. Daughter nuclei are reconstituted.
S. Cytoplasmic separation completes daughter-cell formation.

9. Arrange the following events in one normal proliferative cell cycle.
P. Cellular growth occurs before DNA replication.
Q. DNA amount increases from to .
R. Replicated chromosomes attach to the spindle and align.
S. Sister chromatids separate and daughter nuclei form.
T. Cytokinesis produces two daughter cells.

10. During one substage of prophase I, corresponding maternal and paternal chromosomes begin pairing along their lengths. This association is called:

11. Arrange the events in the most appropriate order during expansion of a cell population from one founding cell.
P. The founding cell grows and prepares for division.
Q. It divides to produce daughter cells.
R. The daughter cells grow before their own divisions.
S. Repeated divisions increase the size of the cell population.

12. Equal groups of cells undergo three rounds of nuclear division. Group P completes cytokinesis after each round, whereas Group Q completes no cytokinesis. At the end, Group Q contains far fewer cellular compartments but many nuclei within each compartment. The observations support the conclusion that:

13. The cell cycle is most accurately described as:

14. A diploid meiocyte has . After premeiotic DNA replication and normal completion of meiosis I, each of the two daughter cells contains:

15. Which symbolic comparison correctly represents the normal final outcomes of division from one diploid parental cell?

16. Control cells in metaphase II align every chromosome individually at the equator. In treated cells, one sister kinetochore of several chromosomes cannot attach to spindle microtubules, while the other attaches normally. The most likely result is:

17. The features of four cells are summarised below.

Which cell most closely represents telophase?

18. In an adult animal, heart cells continue performing their specialised functions but ordinarily do not divide. Another cell population begins dividing when neighbouring cells die and require replacement. This comparison shows that:

19. Arrange the following events from interkinesis to metaphase II.
P. A short interval occurs without DNA replication.
Q. Chromosomes compact again in each haploid cell.
R. The nuclear membrane disappears and a new spindle becomes organised.
S. Individual chromosomes align at the equator.

20. The observations below were recorded in four dividing cells.

Which pair best contrasts the reductional separation of meiosis I with an equational sister-separation event?

21. An unknown dividing cell is haploid and contains DNA. Individual replicated chromosomes are aligned at the equator, the nuclear envelope is absent and sister kinetochores face opposite poles. The cell is most accurately identified as:

22. A treatment doubles M-phase duration from to , while the total cell-cycle duration remains . Under these stated conditions, interphase would:

23. Two homologous chromosomes have moved apart along most of their lengths but remain connected at one or more X-shaped points. The synaptonemal complex is no longer visible. The X-shaped points are:

24. Meiocytes are supplied with a labelled DNA precursor only during the interval between meiosis I and meiosis II. The label is not incorporated into nuclear chromosomes, yet the cells later complete meiosis II normally. The strongest inference is:

25. An ordered cell-cycle diagram contains three consecutive interphase regions P, Q and R. P begins when mitosis ends and finishes when nuclear DNA synthesis starts. Q contains DNA replication, and R lies immediately before M phase. Region P is:

26. Consider the following statements about late prophase.
I. The nucleolus is no longer visibly distinct.
II. The nuclear envelope loses its visible integrity.
III. Golgi complexes and endoplasmic reticulum are not visibly distinct.
IV. Chromosomes begin decondensing into interphase chromatin.

27. Evaluate the following statements about crossing over and chiasmata.
I. Crossing over occurs during pachytene.
II. Chiasmata become clearly evident during diplotene.
III. A visible chiasma corresponds to a site associated with an earlier crossover.
IV. Chiasmata arise through exchange between sister chromatids.

28. A treatment triples the duration of but does not alter the rate of cellular growth, chromosome number or the later durations of S, and M phases. Immediately before the delayed cells enter S phase, they are expected to have:

29. Which statements accurately describe the ploidy of cells undergoing mitosis?
I. In animals, mitosis usually occurs in diploid somatic cells.
II. Haploid cells of a male honey bee can undergo mitosis.
III. Plants can show mitosis in both haploid and diploid phases.
IV. Mitosis necessarily converts a haploid cell into a diploid cell.

30. Four meiotic conditions are compared below.

Which pair of rows contains biologically defensible expectations?

31. Four diploid cells, each with DNA, show the following features.

Which identification is correct?

32. Control cells form a compact metaphase plate. In treated cells, kinetochores remain attached to spindle fibres, but the fibres cannot generate effective movement, and chromosomes stay scattered. The strongest inference is that:

33. Consider the following implications of genetic control over the cell cycle.
I. Similar proliferating cells can show a reproducible order of major events.
II. Genetic control does not require equal cycle duration in every cell type.
III. Disruption of event order may interfere with intact-genome transmission.
IV. Random timing of replication and segregation is sufficient for normal daughter cells.

34. A replicated chromosome lies at the equator with its sister chromatids joined at one constriction. The constriction divides, and the two resulting structures begin moving towards opposite poles. The cell has entered:

35. Assertion: Centromere and kinetochore are not exact synonyms.
Reason: The centromere is the chromosome region joining sister chromatids, while kinetochores on its surface provide spindle-fibre attachment sites.

36. Use the arrangement described here. A haploid cell contains several replicated chromosomes aligned individually at the equator. For each chromosome, the kinetochore of one sister chromatid is connected towards one pole and the kinetochore of the other sister is connected towards the opposite pole. This is:

37. Evaluate the following comparisons between mitosis and meiosis.
I. Both are normally preceded by DNA replication.
II. Mitosis usually contains one nuclear division and produces two daughter cells.
III. Meiosis contains two nuclear divisions and ordinarily produces four haploid cells.
IV. DNA replication normally occurs before both meiosis I and meiosis II.

38. Arrange the following animal-cell events in their normal order.
P. Centrioles duplicate in the cytoplasm.
Q. The cell completes S phase.
R. Duplicated centrosomes move towards opposite poles.
S. Asters and spindle fibres organise the mitotic apparatus.

39. Arrange the following nuclear-envelope changes in their normal meiotic order when telophase-I reconstitution occurs.
P. The envelope disappears during late diakinesis.
Q. It may re-form around chromosome groups in telophase I.
R. It disappears again during prophase II.
S. It forms around the four chromosome groups in telophase II.

40. Replicated cells are divided into control and treatment groups. In both groups, DNA content reaches . Control cells form distinct mitotic chromosomes, whereas treated cells retain diffuse chromatin and fail to proceed normally through mitosis. The treatment most directly interfered with:

41. Four reproductive cycles are described below.

Which cycle demonstrates the chromosome-number consequence expected if reduction division were omitted before normal gamete fusion?

42. A treated meiocyte develops terminalised chiasmata, fully condensed bivalents and an assembled spindle. However, its nucleolus and nuclear envelope remain visibly intact. The treatment most directly disrupted:

43. Protein synthesis is selectively inhibited after a cell completes S phase but before it enters M phase. Which immediate combination is most likely?

44. A graph plots the cytoplasmic volume associated with one nucleus on the y-axis against time on the x-axis. The curve rises during cell growth, drops sharply when mitosis and cytokinesis are completed, and then begins rising again in each daughter cell. The sharp drop is best interpreted as:

45. A meiocyte completes synapsis and later segregates homologous chromosomes normally, but crossing over is experimentally prevented. The most reasonable final outcome is:

46. Cell P and Cell Q both have the condition . Cell P formed after homologous chromosomes separated in meiosis I. Cell Q is a haploid plant cell that completed S phase before mitosis. Which statement correctly distinguishes them?

47. Evaluate the following statements about coordinated cell-cycle events.
I. Genome duplication must precede distribution of replicated chromosomes.
II. Cytokinesis alone guarantees equal genetic information in daughter cells.
III. Loss of coordination between replication and segregation can impair genome transmission.
IV. Cellular growth by itself produces a second chromosome set.

48. A graph plots DNA content per cell on the y-axis against meiotic progression on the x-axis. DNA rises from to before meiosis, falls to after meiosis I, remains constant during interkinesis and falls to after meiosis II. The two decreases differ in that:

49. Control cells entering late prophase show condensed chromosomes, separated centrosomal regions and loss of visible distinction of the nuclear envelope, nucleolus, Golgi complexes and endoplasmic reticulum. Treated cells show chromosome condensation and centrosomal separation, but all four cellular structures remain visibly distinct. The treatment most directly disrupted:

50. A reversibly quiescent cell is stimulated to resume proliferation. Which sequence most accurately represents its return to division?