How many cells or nuclei are present in mature male gametophyte of Angiosperm

Options

A. One
B. Two
C. Three
D. Many

Answer

To determine how many cells or nuclei are present in the mature male gametophyte of angiosperms, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Structure**: The male gametophyte in angiosperms is represented by the pollen grain. Pollen grains are formed from pollen mother cells (PMCs) through two main processes: microsporogenesis and microgametogenesis.

2. **Microsporogenesis**: In this process, one pollen mother cell undergoes meiosis to produce four haploid microspores. This marks the formation of microspores.

3. **Microgametogenesis**: Each microspore then develops into a pollen grain. During this development, a single microspore undergoes mitotic division.

4. **Cell Division**: The mitotic division of the microspore results in the formation of two distinct cells:
- A larger vegetative cell (also known as the tube cell).
- A smaller generative cell.

5. **Generative Cell Division**: The generative cell remains within the cytoplasm of the vegetative cell. Later, this generative cell divides again to form two sperm cells (male gametes).

6. **Final Count of Cells/Nuclei**: At the mature stage, the pollen grain can be in one of two stages:
- **Two-cell stage**: When the generative cell has not yet divided, the pollen grain consists of two nuclei (one in the vegetative cell and one in the generative cell).
- **Three-cell stage**: After the generative cell divides, the pollen grain consists of three nuclei (one in the vegetative cell and two in the sperm cells).

7. **Conclusion**: Regardless of whether the pollen grain is released in the two-cell or three-cell stage, the mature male gametophyte always has two nuclei when it is liberated. Therefore, the answer is that the mature male gametophyte of angiosperms has **2 nuclei**.