What are grana? Where are they present?

Explanation

**Step-by-Step Solution:**

1. **Definition of Grana:**
- Grana are stacks of structures known as thylakoids.
- Thylakoids are disc-shaped membranes that play a crucial role in the light-dependent reactions of photosynthesis.

2. **Function of Grana:**
- The primary function of grana is to facilitate the process of photosynthesis, specifically the light-dependent reactions where light energy is converted into chemical energy.
...