Biology Multiple Choice Questions on “Cell Cycle”.
1. Which of these processes is not a part of the cell cycle?
a) Duplication of genome
b) Division into daughter cells
c) Synthesis of cell organelles
d) Degeneration of centrosome
Answer: d
Clarification: Cell cycle involves duplication of the genome, division of the parent cell into two daughter cells, synthesis of cell organelles for the daughter cells, but centrosomes are not degenerated.
2. Which of these is the correct order of events in the cell cycle?
a) G1 → G2 → S → M
b) G1 → G2 → M → S
c) G1 → S → G2 → M
d) S → M → G1 → G2
Answer: c
Clarification: The cell cycle starts with the first gap phase or G1, followed by the synthesis phase or S phase. This is followed by the second gap phase or G2. These are parts of the interphase, which is then followed by the M phase.
3. What is the duration of cell cycle in yeast?
a) 30 minutes
b) 24 hours
c) 90 minutes
d) 48 hours
Answer: c
Clarification: The duration of the cell cycle of the single celled fungi yeast takes 90 minutes. This means that it undergoes interphase and M phase to produce two new identical daughter cells through cell division.
4. The period between two M phases is called ______
a) interphase
b) prophase
c) prometaphase
d) telophase
Answer: a
Clarification: Two successive M phases or mitosis phases are separated by a period of rest known as interphase. It is the phase in which newly formed daughter cells actively grow and synthesize cellular material for the next M phase.
5. How much time of the entire cell cycle is occupied by interphase?
a) 75%
b) 95%
c) 50%
d) 80%
Answer: b
Clarification: The cell cycle is broadly classified into two phases-the interphase and the M phase. The M phase is the one in which actual cell division takes place. It occurs rapidly and takes up 95% of the duration of the cell cycle.
6. Identify the phase of the cell cycle.
a) Prophase
b) G0
c) G2
d) Telophase
Answer: c
Clarification: The phase to be identified lies between the S phase or the synthesis phase and the M phase or the mitosis phase. Hence, it is the G2 phase or the gap phase 2. Cell growth takes place during this phase.
7. Which process does the M phase of cell cycle start with?
a) Karyokinesis
b) Cytokinesis
c) Interphase
d) Spindle formation
Answer: a
Clarification: The M phase of the cell cycle starts with karyokinesis or the separation of sister chromatids. It ends with cytokinesis or the division of the cytoplasm. The M phase occurs after interphase.
8. In which phase of the cell cycle does DNA replication take place?
a) Anaphase
b) Metaphase
c) Prophase
d) Interphase
Answer: d
Clarification: DNA replication or synthesis takes place in the resting phase or interphase of the cell cycle. It takes place during the S phase or synthesis phase. Prophase, metaphase and anaphase are a part of M phase.
9. What is the interval between mitosis and DNA replication?
a) S phase
b) G2 phase
c) G1 phase
d) M phase
Answer: c
Clarification: G1 phase or gap 1 phase is the interval between the end of mitosis or M phase and the beginning of the replication or the synthesis of DNA in the synthesis phase. G2 phase follows the S phase.
10. DNA synthesis involves an increase in chromosome number. True or false?
a) True
b) False
Answer: b
Clarification: DNA synthesis does not increase the chromosome number. Only the amount of DNA in the cell increases. It doubles in quantity in order to divide it equally between two daughter cells to be produced as a result of mitosis.
11. During S phase of the cell cycle, the amount of DNA ______
a) triples
b) remains the same
c) quadruples
d) doubles
Answer: d
Clarification: During S phase or synthesis phase, DNA synthesis or replication takes place. This is because at the end of every cell division, the cell splits into two daughter cells which have equal amount of DNA. Hence the amount of DNA doubles.
12. In which phase of the cell cycle does centriole duplication take place?
a) S phase
b) G2 phase
c) G1 phase
d) G0 phase
Answer: a
Clarification: Centriole duplication as well as DNA duplication or synthesis takes place in the S phase or the synthesis phase of the cell cycle. DNA duplication does not take place in the gap phases G1, G2 and G0.
13. Protein synthesis takes place in _____
a) G0 phase
b) G1 phase
c) G2 phase
d) S phase
Answer: c
Clarification: Proteins are synthesized in the interphase in order to help initiate the M phase or mitosis phase and so that the two daughter cells each receive adequate protein. It takes place in G2 phase.
14. Which of these cells do not divide?
a) Heart cells
b) Melanocytes
c) Osteocytes
d) Liver cells
Answer: a
Clarification: Melanocytes, osteocytes and liver cells show cell division. Heart cells do not show cell division as the cells have exited the G1 or first gap phase in order to enter a quiescent stage or the G0 phase.
15. In which of these animals does a haploid cell divide mitotically?
a) Humans
b) Male honey bees
c) Female honey bees
d) Rats
Answer: b
Clarification: Haploid cells which have only one copy of chromosomes divide mitotically in male honey bees. This is in contrast to the general pattern of haploid germ cells dividing meiotically in most animals.