Draw a labelled diagram of the sectional view of a mature pollen grain in angiosperms. Explain the functions of its different parts.

Explanation

### Step-by-Step Solution:

1. **Draw the Sectional View of a Mature Pollen Grain**:
- Start by sketching a round or oval shape to represent the pollen grain.
- Divide the pollen grain into two main layers: the outer layer (exine) and the inner layer (intine).
- Inside the pollen grain, draw two nuclei: one larger (vegetative nucleus) and one smaller (generative nucleus).

2. **Label the Parts of the Diagram**:
...