In a mitotic cycle, the correct sequence of phases is
1. S, , , M
2. , S, , M
3. M, , , S
4. , , S, M
During Meiosis 1, in which stage synapsis takes place?
1. | Pachytene | 2. | Zygotene |
3. | Diplotene | 4. | Leptotene |
Match the following events that occur in their respective phases of cell cycle and select the correct option:
Column I | Column II | ||
(a) | G1 phase | (i) | Cell grows and organelle duplication |
(b) | S phase | (ii) | DNA replication and chromosome duplication |
(c) | G2 phase | (iii) | Cytoplasmic growth |
(d) | Metaphase in M-phase | (iv) | Alignment of chromosomes |
Options: | (a) | (b) | (c) | (d) |
1. | (ii) | (iii) | (iv) | (i) |
2. | (iii) | (iv) | (i) | (ii) |
3. | (iv) | (i) | (ii) | (iii) |
4. | (iii) | (ii) | (i) | (iv) |
Identify the meiotic stage in which the homologous chromosomes separate while the sister chromatids remain associated at their centromeres.
1. Metaphase-II
2. Anaphase-I
3. Anaphase-II
4. Metaphase-I
At metaphase, chromosomes are attached to the spindle fibres by their:
1. Centromere
2. Satellites
3. Secondary constrictions
4. Kinetochores
Attachment of spindle fibers to kinetochores of chromosomes becomes evident in:
1. | Anaphase | 2. | Telophase |
3. | Prophase | 4. | Metaphase |
Centromere is required for:
1. Movement of chromosomes toward poles
2. Cytoplasmic cleavage
3. Crossing over
4. Transcription
What occurs in crossing over:
1. Recombination
2. Mutation
3. Independent assortment
4. None
Crossing over that results in genetic recombination in higher organisms occurs between:
1. Non-sister chromatids of a bivalent
2. Two daughter nuclei
3. Two different bivalents
4. Sister chromatids of a bivalent
In the somatic cell cycle:
1. | DNA replication takes place in S-phase |
2. | A short interphase is followed by a long mitotic phase |
3. | \(G_2\) phase follows the mitotic phase |
4. | In the \(G_1\) phase, DNA content is double the amount of DNA present in the original cell |