The centrosome duplicates during:
1. | Early Prophase | 2. | Late Prophase |
3. | S phase | 4. | G2 phase |
Prophase of mitosis is not characterized by:
1. condensation of chromatin
2. migration of centrosomes to opposite poles
3. formation of mitotic apparatus
4. pairing of homologous chromosomes
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
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
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
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
During which stage of mitosis do the following events occur?
I. Centromeres split and chromatids separate
II. Chromatids move to opposite poles
1. | Prophase | 2. | Metaphase |
3. | Anaphase | 4. | Telophase |
Match each item in Column I with one in Column II and select the correct answer from the codes given below:
Column I |
|
Column II |
|
A |
Zygotene |
a |
Pairing of homologous chromosomes |
B |
Pachytene |
b |
Appearance of chiasma |
C |
Diplotene |
c |
Terminalization of chiasma |
D |
Diakinesis |
d |
Crossing over |
Codes
A | B | C | D | |
1. | a | c | b | d |
2. | a | d | b | c |
3. | a | b | c | d |
4. | b | c | d | a |
All the following are significances of mitosis except:
1. Restoration of nuclear/cytoplasmic ratio
2. Growth of living organisms
3. Replacement of lost cells
4. Generation of genetic variation
The correct chronology of stages of Prophase I is:
1. Leptotene – Zygotene – Pachytene – Diplotene – Diakinesis
2. Leptotene – Pachytene – Zygotene – Diplotene – Diakinesis
3. Leptotene – Zygotene – Pachytene – Diakinesis – Diplotene
4. Zygotene – Leptotene – Pachytene – Diakinesis – Diplotene