Assertion. All the enzymes participating in the Krebs cycle reactions occur in the matrix of mitochondria.
Reason. Krebs cycle generates GTP in animal as well as plant cells.

Options

A. If both A and R are true and R is the correct explanation of A
B. If both A and R are true but R is not the correct explanation of A
C. If A is true and R is false
D. If both A and R are false

Answer

To solve the assertion-reason question, we need to analyze both the assertion and the reason provided.

### Step-by-Step Solution:

1. **Understanding the Assertion**: The assertion states that all enzymes participating in the Krebs cycle reactions occur in the matrix of mitochondria.
- The Krebs cycle (also known as the citric acid cycle or TCA cycle) takes place in the mitochondria, specifically in the mitochondrial matrix. However, there is an exception: the enzyme succinate dehydrogenase is located in the inner mitochondrial membrane, not in the matrix.

2. **Evaluating the Assertion**: Since not all enzymes are located in the matrix (due to the presence of succinate dehydrogenase in the membrane), the assertion is **false**.

3. **Understanding the Reason**: The reason states that the Krebs cycle generates GTP in animal cells as well as plant cells.
- In animal cells, the Krebs cycle does indeed generate GTP. However, in plant cells, the Krebs cycle primarily generates ATP instead of GTP.

4. **Evaluating the Reason**: Since the Krebs cycle generates GTP in animals but ATP in plants, the reason is also **false**.

5. **Conclusion**: Both the assertion and the reason are false. Therefore, the correct answer to the question is that both the assertion and the reason are false.

### Final Answer:
Both the assertion and the reason are false.

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