Question

Match the LIST-I with LIST-II: \[ \begin{array}{|l|l|} \hline \textbf{LIST-I (Events)} & \textbf{LIST-II (Stages)} \\ \hline A. \ \text{Double-strand breaks appear} & I. \ \text{Pachytene} \\ B. \ \text{Joint molecules recovered} & II. \ \text{End of zygotene} \\ C. \ \text{Recombinant DNA molecules recovered} & III. \ \text{Diplotene} \\ D. \ \text{Double-strand breaks disappear} & IV. \ \text{Beginning of zygotene} \\ \hline \end{array} \]

• A. A - I, B - III, C - II, D - IV
• B. A - I, B - II, C - IV, D - III
• C. A - IV, B - I, C - III, D - II
• D. A - III, B - IV, C - I, D - II

Hint:

Meiotic events (DSB, joint molecules, recombination) align with zygotene, pachytene, and diplotene stages.

Answer 1

The Correct Option is B

Step 1: Event A - Double-strand breaks arise.
This is an initial meiotic recombination event observed during pachytene. → (A - I)
Step 2: Event B - Joint molecules form.
This happens near the end of zygotene, as chromosomes align and crossing over initiates. → (B - II)
Step 3: Event C - Recombinant DNA molecules emerge.
New recombinant structures develop during the beginning of zygotene. → (C - IV)
Step 4: Event D - Double-strand breaks resolve.
Occurs at the conclusion of the recombination process, identified in diplotene. → (D - III)
Step 5: Final Arrangement.
The accurate sequence is: A - I, B - II, C - IV, D - III.