Biology

Cell Cycle and Chromosomes

1,219 Questions

Explore a curated list of questions covering the cell cycle, mitosis, and meiosis. Topics include DNA replication, chromosomal structures, and genetic disorders. This material is essential for students preparing for biology and general science competitive exams.

Cell cycle eventsDNA replicationMeiosis processChromosomal structuresGenetic disorders

Cell Cycle and Chromosomes Questions

Multiple choice

The disappearance of spindle and uncoiling of chromosomes takes place in ________.

  1. anaphase

  2. telophase

  3. pachytene

  4. metaphase

  5. prophase
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Telophase is the final stage in both meiosis and mitosis in a eukaryotic cell. During telophase, the effects of prophase and prometaphase (the nuclear membrane and nucleolus disintegrating) are reversed. Two daughter nucleiform in each daughter cell, and phosphatases de-phosphorylate the nuclear lamins at the ends of the cell, forming nuclear envelopes around each nucleus.

Multiple choice

Which of the following is not correct with respect to meiosis?

  1. It involves two successive divisions resulting in the formation of four daughter nuclei.

  2. Prophase is of longer duration and complex.

  3. Number of chromosomes in daughter cells is half to that of the mother cells.

  4. It occurs in somatic cells and equational division takes place.

  5. Meiosis forms gametes and spores and maintains the chromosome number constant from generation to generation.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

This statement is not true. It occurs in generative cells and reductional division takes place.

Multiple choice

Mitosis is very significant. Which of the following is not a significance of Mitosis?

  1. It helps to maintain linear heredity of an organism by keeping the chromosome numbers constant in daughter cells.

  2. It helps in development of organism from zygotic stage to adult stage.

  3. It is the means of repair and regeneration of cells and replacement of the old and dead cells.

  4. Sexual reproduction is accomplished only through mitosis.

  5. Details of mitosis are similar in all organisms, which emphasizes the unity of life.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

This statement is false. Asexual reproduction is accomplished only through mitosis.

Multiple choice

The period between two successive mitotic divisions is

  1. diakinesis

  2. mitosis

  3. anaphase

  4. diplotene

  5. interphase
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Interphase is the phase of the cell cycle in which the cell spends the majority of its time and performs the majority of its purposes including preparation for cell division. This is the period between two successive mitotic divisions.

Multiple choice

Colchicine treated cells remain arrested in _____.

  1. Prophase

  2. G2 phase

  3. Metaphase

  4. S phase
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Colchicine is an alkaloid prepared from the dried corns and seeds of Colchicum autumnale (autumn crocus). It inhibits microtubule polymerisation by binding to tubulin. During mitosis, use of colchicine inhibits spindle formation and the cell division remains arrested in its metaphase stage.

Multiple choice

G1 phase of cell cycle is usually absent in __________.

  1. Intestinal epithelial cells

  2. HeLa cells in culture

  3. Early cleavage stage cells

  4. Senescent fibroblast cells
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The rate of cell division in early cleavage cells is very high. So in these cells, cell cycle consists of only S and M phases. During S phase, cells synthesise the necessary materials for division and then, they proceeds towards the mitotic division that is the M phase. It is actually a time saving procedure for producing huge numbers of cells in shorter time span during early cleavage.

Multiple choice

In eukaryotes, two types of cell divisions partition the genetic material into offspring or daughter cells. Mitosis is the process that partitions newly replicated chromosomes equally into two daughter cells. Meiosis is a specialised form of cell division in which number of chromosomes is reduced to half.

An organism has 56 chromosomes in its diploid stage. How many chromosomes are present in somatic cells?

  1. 112

  2. 56

  3. 28

  4. 45
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Somatic cells are diploid and undergo mitotic division. So, the number of chromosomes remains same in the daughter cells.

Multiple choice

In eukaryotes, two types of cell divisions partition the genetic material into offspring or daughter cells. Mitosis is the process that partitions newly replicated chromosomes equally into two daughter cells. Meiosis is a specialised form of cell division in which number of chromosomes is reduced to half.

How many chromosomes are present in the gametes of the above mentioned organisms?

  1. 56

  2. 14

  3. 28

  4. 112
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Gamete cells undergo meiotic division and they have haploid number of chromosomes, i.e. half of the chromosomes present in the somatic cells. In diploid cells, number of chromosomes is 56. So, number of chromosomes in gamete cells is 56/2 = 28.

Multiple choice

Cytokinesis occurs in an animal cell by

  1. furrowing

  2. burrowing

  3. borrowing

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In cell biology, the cleavage furrow is the indentation of the cell's surface that begins the progression of cleavage, by which animal and some algal cells undergo cytokinesis, the final splitting of the membrane, in the process of cell division.

Multiple choice

Centromeres line up in the equator during

  1. prophase

  2. metaphase

  3. anaphase

  4. telophase
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

 Centromeres line up in the equator during metaphase.Metaphase is the third phase of mitosis, the process that separates duplicated genetic material carried in the nucleus of a parent cell into two identical daughter cells.