The development of male gametophyte in angiosperms is

Options

A. Partly in-situ in anther and partly ex-situ on stigma.
B. Fully in-situ in anther
C. Fully Ex-situ on stigma
D. In-vitro only

Answer

To solve the question regarding the development of male gametophyte in angiosperms, we will analyze the options provided and determine the correct answer based on our understanding of plant biology.

### Step-by-Step Solution:

1. **Understanding Male Gametophyte Development**:
- In angiosperms, the male gametophyte is represented by pollen grains. The development of these pollen grains occurs within the anthers of the flowers.

2. **Analyzing Option A**:
- Option A states "partially in situ in anther." This means that the male gametophyte (pollen grains) develops partially within the anther, which is correct. The pollen grains are formed within the anther and are released when mature.

3. **Analyzing Option B**:
- Option B states "fully in situ in anther." This is misleading because while the pollen grains do develop in the anther, they are not fully mature until they are released. Thus, this option is incorrect.

4. **Analyzing Option C**:
- Option C states "fully exe to on stigma." This suggests that the male gametophyte develops fully on the stigma, which is incorrect. The development occurs in the anther, not on the stigma.

5. **Analyzing Option D**:
- Option D states "in vitro only." This implies that the male gametophyte develops outside of the plant, which is also incorrect. The development occurs within the plant's anther.

6. **Conclusion**:
- The only correct option is A: "partially in situ in anther." This accurately describes the development of the male gametophyte in angiosperms.

### Final Answer:
The development of male gametophyte in angiosperms is **partially in situ in anther** (Option A).