Mature male gametophyte is made up of

Options

A. one celled
B. two celled
C. one celled and two nucleate
D. three celled

Answer

To answer the question "Mature male gametophyte is made up of," we need to understand the structure of the mature male gametophyte, which is represented by the pollen grain in flowering plants. Here’s a step-by-step breakdown:

### Step-by-Step Solution:

1. **Definition of Mature Male Gametophyte**:
- The mature male gametophyte is commonly referred to as a pollen grain. It plays a crucial role in the reproduction of flowering plants.

2. **Structure of Pollen Grain**:
- A pollen grain consists of a two-layered wall structure. The outer layer is known as the exine, which is made up of sporopollenin, a tough and resistant biopolymer. The inner layer is called the intine, which is composed of cellulose and pectin.

3. **Cell Composition**:
- Inside the pollen grain, there are two types of cells:
- **Vegetative Cell**: This is the larger cell that contains one nucleus. It is responsible for the growth of the pollen tube.
- **Generative Cell**: This is a smaller cell located within the cytoplasm of the vegetative cell. It also contains one nucleus.

4. **Mitotic Division**:
- The generative cell undergoes mitotic division after the pollen grain is formed. This division results in the formation of two male gametes (sperm cells).

5. **Final Composition**:
- After the mitotic division, the mature pollen grain consists of three cells:
- One vegetative cell (with one nucleus)
- Two male gametes (derived from the generative cell after its division)

6. **Conclusion**:
- Therefore, the mature male gametophyte (pollen grain) is made up of **three cells**: one vegetative cell and two male gametes.

### Final Answer:
The mature male gametophyte is made up of **three cells**.

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