Spirogyra is a sexually reproducing alga in which vegetative thallus is haploid. In Spirogyra, meiosis

Options

A. never occurs
B. occurs at time of gamete production
C. occurs after fertilisation
D. occurs during vegetative growth.

Answer

**Step-by-Step Solution:**

1. **Understanding Spirogyra**: Spirogyra is a type of green algae that reproduces sexually. Its vegetative thallus is haploid, meaning it contains a single set of chromosomes.

2. **Meiosis Definition**: Meiosis is a type of cell division that reduces the chromosome number by half, resulting in four haploid daughter cells from one diploid parent cell. It is essential for sexual reproduction as it produces gametes.

3. **Identifying When Meiosis Occurs in Spirogyra**:
- **Option 1: Never occurs**: This option is incorrect because meiosis does occur in Spirogyra.
- **Option 2: At the time of gamete production**: This option is also incorrect. During gamete production, mitosis occurs, not meiosis.
- **Option 3: After fertilization**: This is the correct option. In Spirogyra, meiosis occurs after fertilization, leading to the formation of haploid spores.
- **Option 4: During vegetative growth**: This option is incorrect as meiosis does not occur during vegetative growth.

4. **Conclusion**: The correct answer is that meiosis occurs after fertilization in Spirogyra.

**Final Answer**: Meiosis occurs after fertilization in Spirogyra.

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