In the Hatch and slack pathway, malic acid is formed in

Options

A. Mesophyll cell maize leaf
B. Mesophyll cell of tomato
C. Mesophyll cell of banana
D. Mesophyll of cactus

Answer

To solve the question regarding where malic acid is formed in the Hatch and Slack pathway, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Hatch and Slack Pathway**: The Hatch and Slack pathway, also known as the C4 pathway, is a photosynthetic process that occurs in certain plants, particularly those adapted to dry and tropical environments.

2. **Identify the Key Components**: In this pathway, the initial fixation of carbon dioxide occurs in the mesophyll cells, where phosphoenolpyruvate (PEP) combines with carbon dioxide to form oxaloacetic acid (OAA).

3. **Formation of Malic Acid**: The oxaloacetic acid (OAA), which is a 4-carbon compound, can be converted into malic acid or aspartic acid. The formation of malic acid specifically occurs in the mesophyll cells.

4. **Location of Malic Acid Formation**: Since the question asks where malic acid is formed, we need to focus on the mesophyll cells of the plants that utilize the C4 pathway.

5. **Evaluate the Options**: The options provided are:
- A) Mesophyll cells in maize leaf
- B) Mesophyll cells of tomato
- C) Mesophyll cells of banana
- D) Mesophyll cells of cactus

Among these, maize is a well-known C4 plant that utilizes the Hatch and Slack pathway.

6. **Conclusion**: Therefore, the correct answer is that malic acid is formed in the mesophyll cells of maize leaf.

### Final Answer:
**Malic acid is formed in the mesophyll cells of maize leaf. (Option A)**

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