Assertion (A) `:` Replication and transcription occur in the nucleus but translation occurs in the cytoplasm.
Reason (R ) `:` m-RNA is transferred from the nucleus into the cytoplasm where ribosomes and amino acids are available for protein synthesis.

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

**Step-by-Step Solution:**

1. **Understanding the Assertion (A)**: The assertion states that replication and transcription occur in the nucleus, while translation occurs in the cytoplasm.
- **Explanation**: Replication is the process of copying DNA, and transcription is the process of synthesizing mRNA from DNA. Both of these processes take place in the nucleus because that is where the DNA is located.

2. **Understanding the Reason (R)**: The reason states that mRNA is transferred from the nucleus into the cytoplasm, where ribosomes and amino acids are available for protein synthesis.
- **Explanation**: After mRNA is synthesized in the nucleus, it exits through nuclear pores into the cytoplasm. In the cytoplasm, ribosomes (the machinery for protein synthesis) and amino acids (the building blocks of proteins) are present, allowing for translation to occur.

3. **Connecting Assertion and Reason**: Both the assertion and the reason are true statements. The assertion correctly describes the locations of replication, transcription, and translation, while the reason accurately explains why translation occurs in the cytoplasm.
- **Conclusion**: Since both the assertion and reason are true, and the reason supports the assertion, the correct answer is that both the assertion and reason are true and the reason is correct for the assertion.

**Final Answer**: Both Assertion (A) and Reason (R) are true, and R is the correct explanation for A.

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