In an angiosperm, microsporangium is

Options

A. stamen
B. pollen grains
C. Ovule
D. pollen sacs

Answer

To solve the question about what a microsporangium is in an angiosperm, we can break down the information step by step.

### Step-by-Step Solution:

1. **Understanding Angiosperms**:
- Angiosperms are flowering plants that produce seeds enclosed within a fruit. They have distinct reproductive structures.

**Hint**: Remember that angiosperms are characterized by their flowers and seeds.

2. **Identifying Microsporangium**:
- The microsporangium is a structure that produces microspores, which develop into pollen grains.

**Hint**: Focus on the role of microsporangium in reproduction.

3. **Structure of Microsporangium**:
- In angiosperms, the microsporangium is typically found within the anther of the stamen. It is surrounded by layers including the epidermis, endothelium, middle layers, and tapetum.

**Hint**: Visualize the layers surrounding the microsporangium to understand its structure.

4. **Function of Microsporangium**:
- The main function of the microsporangium is to produce pollen grains. The microspores formed in the microsporangium undergo mitosis to develop into pollen grains.

**Hint**: Think about the transformation from microspores to pollen grains.

5. **Conclusion**:
- From the options provided (stamen, pollen grains, ovule, pollen sac), the correct identification of the microsporangium in angiosperms is that it is synonymous with the pollen sac, where pollen grains are produced.

**Hint**: Relate the microsporangium directly to its function in producing pollen.

### Final Answer:
In an angiosperm, the microsporangium is the **pollen sac**.