Select the correct sequence of events occurring during Prophase-I of Meiosis-I:
(a) | Nuclear envelope breakdown |
(b) | Synaptonemal complex formation |
(c) | Compaction of chromosomes |
(d) | Terminalisation of chiasmata |
(e) | Crossing over |
Choose the most appropriate answer from the options given below:
1. (c) → (b) → (e) → (d) → (a)
2. (c) → (a) → (b) → (d) → (e)
3. (b) → (c) → (a) → (d) → (e)
4. (c) → (a) → (b) → (e) → (d)
Assertion(A): | Mitosis does play a role in gamete formation. |
Reason(R): | Haploid organisms divide by mitosis. |
1. | Both (A) & (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) & (R) are true but (R) is not the correct explanation of (A) |
3. | (A) is a true statement but (R) is false. |
4. | Both (A) and (R) are false statements. |
1. | segregation of daughter chromosomes during anaphase |
2. | poleward migration of centrosomes during prophase |
3. | synthesis of sporopollenin during G1 and G2 phases |
4. | construction of the cell plate during cytokinesis |
Assertion (A): | Meiosis leads to recombinations of genes. |
Reason (R): | Crossing over occurs in pachytene sub-stage of prophase I of meiosis. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |
Assertion(A): | Tendency of parental combinations to remain together is called crossing over. |
Reason(R): | Crossing over provides proof in favour of the linear arrangement of genes on chromosomes. |
1. | Both (A) & (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) & (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is a true statement but (R) is false.. |
4. | Both (A) and (R) are false statements. |
1. | telophase | 2. | anaphase |
3. | prophase | 4. | metaphase |
A. | Condensation of chromosomes is complete |
B. | Chromosomes are moved to spindle equator |
C. | Daughter chromosomes begin their migration towards the opposite poles |
D. | Spindle fibers attach to kinetochores |
E. | Chromosome moves away from the equatorial plate |