The structure that are formed by stacking of organised flattened membranous sacs in the chloroplasts are

Options

A. cristae
B. grana
C. stroma lamellae
D. stroma

Answer

**Step-by-Step Solution:**

1. **Understanding Chloroplast Structure**:
- Chloroplasts are specialized organelles found in plant cells responsible for photosynthesis. They contain chlorophyll, the green pigment that captures light energy.

2. **Identifying Membranous Sacs**:
- Within chloroplasts, there are organized structures made up of flattened membranous sacs. These sacs are crucial for the chloroplast's function.

3. **Recognizing the Stacked Structure**:
- The flattened membranous sacs stack on top of each other to form a structure. This stacking is essential for maximizing the surface area for light absorption.

4. **Naming the Structure**:
- The stacked structure formed by these flattened membranous sacs is called **grana** (singular: granum). Each granum consists of multiple thylakoids, which are the individual membranous sacs.

5. **Interconnection of Grana**:
- Grana are interconnected by stroma lamellae, which are thin membranes that help in the communication between different grana.

6. **Conclusion**:
- Therefore, the correct answer to the question is that the structures formed by stacking of organized flattened membranous sacs in the chloroplasts are called **grana**.

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