The start of the second phase of mitosis, metaphase, is marked by:
1. complete disintegration of the nuclear envelope
2. alignment of chromosomes at the equatorial plate
3. de-condensation of chromatin
4. reappearance of the nucleolus
Plants show mitotic divisions:
1. only in germ line cells
2. at the root apex and shoot apex only
3. in both diploid and haploid cells
4. for the productions of gametes only
Consider the given two statements:
I: | Morphology of chromosomes is best studied at metaphase |
II: | At this stage, a chromosome is made up of two sister chromatids, held together at the centromere |
1. Both I and II are True and II explains I
2. Both I and II are True but II does not explain I
3. I is True but II is False
4. I is False but II is True
If a cell had 4[2 pairs] chromosomes at G1 phase, what would be the number of chromosomes in this cell at the end of anaphase?
1. | 2 | 2. | 4 |
3. | 6 | 4. | 8 |
The phase of the cell cycle that lasts for the least time is the:
1. | G1 phase | 2. | S phase |
3. | G2 phase | 4. | M phase |
All the following key events take place during telophase of mitosis except:
1. Chromosomes cluster at the opposite spindle poles
2. Chromosomes become discrete
3. Nuclear envelope reforms
4. Nucleolus, ER and Golgi complex reform
In a plant cell during the S phase of the cell cycle:
I: | DNA replication begins in the nucleus |
II: | Centriole duplicates in the cytoplasm |
1. Only I is correct
2. Only II is correct
3. Both I and II are correct
4. Both I and II are incorrect
Identify the incorrect statement regarding cytokinesis:
1. | Animal cells divide by cleavage furrow |
2. | Cell plate formation takes place during cytokinesis in plant cells |
3. | The cell wall formation in plant cells starts near the existing lateral walls and grows inwards |
4. | At cytokinesis, mitochondria and plastids are distributed between daughter cells |
Liquid endosperm in coconut forms due to:
1. Failure of cytokinesis after karyokinesis
2. Failure of karyokinesis before cytokinesis
3. Disruption of spindle fibers at metaphase
4. Continued DNA replication during cytokinesis
At the metaphase plate:
1. | The sister chromatids of a chromosome are connected by their kinetochores to the spindle fibers from the same pole |
2. | The non sister chromatids of a chromosome are connected by their kinetochores to the spindle fibers from the same pole |
3. | The sister chromatids of a chromosome are connected by their kinetochores to the spindle fibers from the opposite poles |
4. | The non sister chromatids of a chromosome are connected by their kinetochores to the spindle fibers from the opposite poles |