In angiosperm, mature male gametophyte is produced after meiosis and mitosis

Options

A. 1,2
B. 1,1
C. 1,3
D. 1,4

Answer

To determine how many meiosis and mitosis divisions are required to produce a mature male gametophyte in angiosperms, we can break down the process step by step:

### Step-by-Step Solution:

1. **Start with the Microspore Mother Cell (MMC)**:
- The process begins with the Microspore Mother Cell, which is diploid (2n).

2. **Meiosis**:
- The Microspore Mother Cell undergoes meiosis, resulting in four haploid microspores (n).
- This step is crucial as it reduces the chromosome number by half and produces the microspores.

3. **Mitosis of Microspores**:
- Each haploid microspore undergoes mitosis.
- During this division, each microspore's nucleus divides to form two types of nuclei: one large vegetative nucleus and one small generative nucleus.
- This results in the formation of a pollen grain, which contains both the vegetative and generative nuclei.

4. **Pollination and Further Mitosis**:
- Upon pollination, the generative cell (which is part of the pollen grain) enters the pollen tube.
- Inside the pollen tube, the generative cell undergoes another mitotic division, resulting in the formation of two non-motile male gametes.

5. **Summary of Divisions**:
- In total, there is **1 meiosis** (to produce the microspores) and **2 mitotic divisions** (one for the formation of the vegetative and generative nuclei and another for the generative cell in the pollen tube).

### Final Answer:
- **Meiosis**: 1
- **Mitosis**: 2

Thus, the answer is **1 meiosis and 2 mitosis**.

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