Pollen grain is liberated in

Options

A. One celled state
B. Two celled state
C. Three called state
D. Two or three celled state.

Answer

**Step-by-Step Solution:**

1. **Understanding Pollen Grain Formation**: In angiosperms (flowering plants), pollen grains are formed through a process called microsporogenesis, where microspores develop into pollen grains.

2. **Cell Division of Pollen Grain**: After the formation of the pollen grains, they undergo mitosis. This process results in the formation of two types of cells within the pollen grain: the vegetative cell and the generative cell.

3. **Identifying the Cells**:
- The **vegetative cell** is larger and contains a larger nucleus.
- The **generative cell** is smaller and has a flattened nucleus.

4. **Stages of Liberation**:
- In approximately **60% of angiosperms**, pollen grains are liberated at the **two-celled stage**, meaning they have one vegetative cell and one generative cell.
- In the remaining **40% of angiosperms**, pollen grains are liberated at the **three-celled stage**, where the generative cell divides again to form two sperm cells.

5. **Conclusion**: Therefore, pollen grains can be liberated in both the two-celled and three-celled stages.

**Final Answer**: Pollen grain is liberated in the two-celled and three-celled stages.

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