In bacteria the cell cycle is divided into:
1. Only 1 phase
2. Two stages
3. Three periods
4. Four classes
The G0 stage of the cell cycle is irreversible in:
I. Quiescent cells
II. Senescent cells
III. Terminally differentiated cells
1. I and II only
2. I and III only
3. II and III only
4. I, II and III
If a cell in S phase is fused with a cell in G1:
1. The G1 nucleus immediately enters the S phase
2. The S nucleus stops DNA replication
3. The G1 nucleus directly enters G2 phase
4. Both nuclei enter the M phase immediately
A point in the animal cell cycle, at which the cell becomes "committed" to the cell cycle, occurs in:
1. | G1 phase | 2. | S phase |
3. | G2 phase | 4. | M phase |
During what phase in the cell cycle would you find the most DNA per cell?
1. G1 | 2. G2 |
3. S | 4. Prophase II |
The phase of the cell cycle that is expected to be the most variable in duration in different types of cells in an animal will be:
1. G1 | 2. S |
3. G2 | 4. M |
Onion root tip has 16 chromosomes in each cell. How many chromosomes will the cell respectively have at G1 phase, after S phase and after M phase?
1. | 16, 32, 16 | 2. | 16, 32, 8 |
3. | 16, 16, 8 | 4. | 16, 16, 16 |
Destruction of both centrosomes with a laser beam in an animal cell:
1. will prevent both mitosis and cytokinesis
2. prevents cytokinesis even if mitosis has been completed normally
3. permits cytokinesis but the daughter cells fail to enter a new S phase
4. prevents mitosis but permits cytokinesis
Which of the following statements is not true for cancer cells in relation to mutations?
1. Mutations in proto-oncogenes accelerate the cell cycle.
2. Mutations destroy telomerase inhibitor.
3. Mutations inactivate the cell control.
4. Mutations inhibit production of telomerase.
Telomerase is an enzyme which is a:
1. Ribonucleoprotein
2. Simple protein
3. RNA
4. Repetitive DNA