Class 11 Biology MCQ – Cell Cycle and Cell Division

1. The phase of the cell cycle during which DNA replication occurs is:

a) G1 phase
b) G2 phase
c) S phase
d) M phase

Answer:

c) S phase

Explanation:

S phase (synthesis phase) is when DNA replication takes place, ensuring each daughter cell receives an exact copy.

2. The process by which a single eukaryotic cell divides into two identical daughter cells is:

a) Mitosis
b) Meiosis
c) Cytokinesis
d) Translation

Answer:

a) Mitosis

Explanation:

Mitosis ensures that two daughter cells have the same number of chromosomes as the parent cell.

3. Which stage of mitosis is characterized by the alignment of chromosomes at the equator of the cell?

a) Prophase
b) Metaphase
c) Anaphase
d) Telophase

Answer:

b) Metaphase

Explanation:

During metaphase, chromosomes line up at the equatorial plane, ensuring their proper segregation.

4. During which phase of meiosis does crossing over occur?

a) Prophase I
b) Metaphase I
c) Anaphase I
d) Prophase II

Answer:

a) Prophase I

Explanation:

Crossing over occurs during prophase I, allowing exchange of genetic material between homologous chromosomes.

5. The primary significance of meiosis is to:

a) Ensure growth
b) Aid in repair
c) Ensure genetic variation
d) Produce identical cells

Answer:

c) Ensure genetic variation

Explanation:

Meiosis produces gametes with half the number of chromosomes, which upon fusion, ensure genetic diversity.

6. Cytokinesis in plant cells involves the formation of:

a) Cleavage furrow
b) Cell plate
c) Centrioles
d) Spindle fibers

Answer:

b) Cell plate

Explanation:

A cell plate eventually becomes the cell wall, dividing the plant cell into two.

7. Which cellular structure is responsible for organizing the mitotic spindle?

a) Lysosome
b) Centrosome
c) Golgi apparatus
d) Endoplasmic reticulum

Answer:

b) Centrosome

Explanation:

Centrosomes contain centrioles in animal cells and help organize the spindle fibers during cell division.

8. Which phase immediately follows mitosis?

a) G1 phase
b) G2 phase
c) S phase
d) Cytokinesis

Answer:

d) Cytokinesis

Explanation:

Cytokinesis is the physical division of the cytoplasm, following mitosis.

9. How many divisions occur in meiosis?

a) One
b) Two
c) Three
d) Four

Answer:

b) Two

Explanation:

Meiosis consists of two divisions – Meiosis I and Meiosis II.

10. The phase in which nuclear envelope reforms around the chromosomes is:

a) Prophase
b) Metaphase
c) Anaphase
d) Telophase

Answer:

d) Telophase

Explanation:

Telophase marks the reformation of the nuclear envelope and the end of nuclear division.

11. A diploid cell has 40 chromosomes. After meiosis, each gamete will have:

a) 20 chromosomes
b) 40 chromosomes
c) 10 chromosomes
d) 80 chromosomes

Answer:

a) 20 chromosomes

Explanation:

Meiosis halves the chromosome number, so a diploid cell with 40 chromosomes will produce gametes with 20 chromosomes.

12. The point where two chromatids are attached to each other in a chromosome is called:

a) Telomere
b) Centriole
c) Centromere
d) Kinetochore

Answer:

c) Centromere

Explanation:

The centromere holds sister chromatids together until they are separated during cell division.

13. In which phase of the cell cycle does the cell prepare for DNA replication?

a) G1 phase
b) G2 phase
c) S phase
d) M phase

Answer:

a) G1 phase

Explanation:

During the G1 phase, the cell grows and prepares for DNA synthesis that occurs in the S phase.

14. Which phase of mitosis is characterized by the separation of sister chromatids?

a) Prophase
b) Metaphase
c) Anaphase
d) Telophase

Answer:

c) Anaphase

Explanation:

Anaphase sees the pulling apart of sister chromatids towards opposite poles of the cell.

15. G0 phase of the cell cycle is characterized by:

a) Rapid cell division
b) DNA replication
c) Cell differentiation
d) Cell in a resting state

Answer:

d) Cell in a resting state

Explanation:

Cells that exit the cycle and enter G0 are in a non-dividing, quiescent state.

16. Cells that are no longer capable of dividing, like muscle and nerve cells, are said to be in:

a) G1 phase
b) G2 phase
c) S phase
d) G0 phase

Answer:

d) G0 phase

Explanation:

These cells exit the cell cycle and remain in the G0 phase.

17. Chromatids separate from each other during:

a) Meiosis I
b) Meiosis II
c) Mitosis
d) Both Meiosis II and Mitosis

Answer:

d) Both Meiosis II and Mitosis

Explanation:

Sister chromatids separate during Anaphase of Mitosis and Anaphase II of Meiosis.

18. The process by which cytoplasm divides in an animal cell is called:

a) Binary fission
b) Cytokinesis
c) Cleavage
d) Budding

Answer:

b) Cytokinesis

Explanation:

Cytokinesis is the process by which the cytoplasm divides after mitosis or meiosis.

19. The term 'karyokinesis' refers to:

a) Division of cytoplasm
b) Division of nucleus
c) Formation of spindles
d) Formation of chromosomes

Answer:

b) Division of nucleus

Explanation:

Karyokinesis is the division of the cell nucleus during mitosis.

20. The phase of cell cycle during which RNA and protein synthesis occurs extensively is:

a) G1 phase
b) G2 phase
c) S phase
d) M phase

Answer:

b) G2 phase

Explanation:

In G2 phase, the cell prepares for mitosis and there's extensive synthesis of RNA and proteins.

Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top