Main site of photosynthesis / starch synthesis is

Options

A. palisade parenchyma
B. spongy parenchyma
C. Guard cells
D. bundle sheath cells

Answer

**Step-by-Step Solution:**

1. **Understanding Photosynthesis**: Photosynthesis is the process by which green plants, algae, and some bacteria convert light energy into chemical energy stored in glucose. This process primarily occurs in the leaves of plants.

2. **Identifying Leaf Structure**: In the leaf, there are two main types of mesophyll cells: palisade parenchyma and spongy parenchyma. The palisade parenchyma is located just beneath the upper epidermis, while the spongy parenchyma is found below it, closer to the lower epidermis.

3. **Palisade Parenchyma**: The palisade parenchyma cells are tightly packed and contain a high number of chloroplasts, which are the organelles responsible for photosynthesis. This compact arrangement allows for maximum light absorption.

4. **Spongy Parenchyma**: In contrast, spongy parenchyma cells are loosely arranged with air spaces between them. They also contain chloroplasts, but in fewer numbers compared to the palisade parenchyma.

5. **Other Cell Types**: Guard cells, which surround the stomata (pores for gas exchange), and bundle sheath cells, which surround vascular tissues, also contain chloroplasts. However, their numbers are lower compared to the palisade parenchyma.

6. **Conclusion**: Given that the palisade parenchyma has a higher concentration of chloroplasts and is more densely packed, it serves as the main site for photosynthesis and starch synthesis in the leaf.

7. **Final Answer**: The main site of photosynthesis and starch synthesis is the **palisade parenchyma**.

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