In angiosperms pollination occurs when pollen grains are in
a) 2-celled stage
b) 3-celled stage
c) 2 or 3 celled state
d) Uninucleate stage

Options

A. 2-celled stage
B. 3-celled stage
C. 2 or 3 celled state
D. Uninucleate stage

Answer

To solve the question regarding the stage at which pollination occurs in angiosperms, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Pollen Grains**: Pollen grains are the male gametophytes of flowering plants (angiosperms). They are crucial for the process of pollination.

2. **Structure of Pollen Grains**: Pollen grains typically consist of two main types of cells:
- **Vegetative Cell**: This is the larger cell that provides nutrition.
- **Generative Cell**: This smaller cell carries the genetic material.

3. **Cellular Stages of Pollen Grains**: Pollen grains can exist in different cellular stages:
- **2-celled Stage**: This stage consists of one vegetative cell and one generative cell.
- **3-celled Stage**: In this stage, the generative cell divides to form two sperm cells, resulting in one vegetative cell and two generative cells.

4. **Pollination Process**: Pollination is the transfer of pollen grains from the male part of the flower (anther) to the female part (stigma). For successful fertilization to occur, the pollen grain must be in a suitable cellular stage.

5. **Percentage of Pollen Grains in Each Stage**:
- A significant percentage (about 60%) of pollen grains are found in the 2-celled stage.
- A smaller percentage (about 40%) are in the 3-celled stage.

6. **Conclusion**: Since pollination can occur when pollen grains are either in the 2-celled stage or the 3-celled stage, the correct answer to the question is that pollination occurs when pollen grains are in the **2 or 3 celled stage**.

### Final Answer:
**c) 2 or 3 celled stage**

---