The inner wall of pollen grain is called intine.

Answer

### Step-by-Step Solution:

1. **Understanding Pollen Grain Structure**:
- Pollen grains are the male gametophytes in flowering plants and consist of two main layers: the outer layer and the inner layer.

2. **Identifying the Layers**:
- The outer layer of the pollen grain is known as **Exine**. This layer is typically tough and provides protection to the pollen grain.
- The inner layer is called **Intine**. This layer is softer and is located beneath the Exine.

3. **Composition of Intine**:
- The Intine is primarily composed of two substances: **Cellulose** and **Pectin**. These components contribute to the structure and function of the Intine.

4. **Conclusion**:
- The statement that "the inner wall of pollen grain is called Intine" is indeed true, as it accurately describes the structure of pollen grains.