A number of organised flattened membranous sacs present in the stroma are

Options

A. Grana
B. Fret membranes
C. Thylakoids
D. Spherosomes

Answer

To answer the question "A number of organized flattened membranous sacs present in the stroma are," we need to analyze the components of chloroplasts, which are the organelles responsible for photosynthesis in plants.

### Step-by-Step Solution:

1. **Understanding Chloroplast Structure**:
- Chloroplasts are membrane-bound organelles found in plant cells. They contain chlorophyll, which is essential for photosynthesis.

2. **Identifying Key Components**:
- Inside the chloroplast, there is a fluid-filled space known as the **stroma**. This stroma contains various structures necessary for photosynthesis.

3. **Recognizing Thylakoids**:
- Within the stroma, there are flattened sac-like structures called **thylakoids**. These thylakoids are essential for the light-dependent reactions of photosynthesis.

4. **Formation of Grana**:
- Thylakoids can be organized into stacks known as **grana** (singular: granum). Each granum consists of multiple thylakoids stacked together.

5. **Conclusion**:
- The question specifically asks for "a number of organized flattened membranous sacs present in the stroma." The organized stacks of thylakoids are referred to as **grana**. Therefore, the correct answer is **grana**.

### Final Answer:
**Grana**