The microtubules from opposite poles of the spindle get attached to the kinetochores of sister chromatids during :

Question

Accepted Answer

The correct answer is Option 3: Metaphase-II. Here is a detailed explanation supporting this choice and why the other options are incorrect:

1. **Explanation for Option 3 (Metaphase-II):**
   - During Metaphase-II of meiosis, the microtubules from opposite poles of the spindle attach to the kinetochores of sister chromatids. This is a crucial step in ensuring that the sister chromatids are aligned at the metaphase plate and are ready to be separated into different cells. The attachment of microtubules to kinetochores is essential for the proper segregation of chromatids during Anaphase-II. This process ensures that each daughter cell receives the correct number of chromosomes, maintaining genetic stability.

2. **Why Option 1 (Prophase-II) is incorrect:**
   - In Prophase-II, the chromosomes condense, and the nuclear envelope breaks down, but the microtubules have not yet attached to the kinetochores. The spindle apparatus begins to form, but the specific attachment of microtubules to kinetochores occurs later, during Metaphase-II.

3. **Why Option 2 (Prophase-I) is incorrect:**
   - Prophase-I is a stage in the first meiotic division where homologous chromosomes pair up and exchange genetic material through crossing over. While the spindle apparatus begins to form, the attachment of microtubules to kinetochores of sister chromatids is not a characteristic event of Prophase-I. Instead, this attachment is a hallmark of Metaphase-II.

4. **Why Option 4 (Anaphase-II) is incorrect:**
   - Anaphase-II is the stage following Metaphase-II, where the sister chromatids are pulled apart toward opposite poles of the cell. By this stage, the microtubules have already attached to the kinetochores during Metaphase-II, and their role in Anaphase-II is to facilitate the separation of chromatids, not their initial attachment.

In summary, the attachment of microtubules from opposite poles to the kinetochores of sister chromatids is a defining event of Metaphase-II, making Option 3 the correct answer.