At what stage the pollen grains shed ?

Options

A. 2-3 celled
B. one celled
C. four celled
D. five celled

Answer

### Step-by-Step Solution:

1. **Understanding Pollen Grain Development**: Pollen grains are formed from microspore mother cells (microsporocytes) located inside the anthers of flowers.

2. **Microspore Formation**: The microspore mother cell undergoes meiosis to produce four haploid microspores. Each of these microspores can develop into a pollen grain.

3. **Pollen Grain Structure**: The pollen grain typically consists of two types of cells:
- **Vegetative Cell (Tube Cell)**: This cell is responsible for forming the pollen tube during fertilization.
- **Generative Cell**: This cell divides to form two male gametes.

4. **Stages of Pollen Grain Shedding**:
- Pollen grains can be shed at different developmental stages:
- **Two-celled Stage**: In some plants, such as pea, the pollen is shed when it has one vegetative cell and one generative cell.
- **Three-celled Stage**: In other plants, like wheat, the pollen is shed when it has one vegetative cell and two generative cells (after the generative cell divides).

5. **Conclusion**: The shedding of pollen grains can occur at either the two-celled stage or the three-celled stage, depending on the plant species. However, the more common stage for shedding is the three-celled stage.

### Final Answer:
Pollen grains are typically shed at the three-celled stage, but they can also be shed at the two-celled stage in some plants.

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