Assertion A non-overlapping code means that a base in mRNA is not used for different codons
Reason In translating mRNA molecules, the codons do not overlap but are read sequentially

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**: The assertion states that a non-overlapping code means that a base in mRNA is not used for different codons. This is true because in a non-overlapping genetic code, each nucleotide (base) is part of only one codon and does not contribute to the formation of multiple codons.

2. **Understanding the Reason**: The reason given is that in translating mRNA molecules, the codons do not overlap but are read sequentially. This is also true. Codons are read one after the other, without any overlap, meaning that each codon is distinct and separate from the others.

3. **Evaluating the Relationship**: While both the assertion and the reason are true, the reason does not specifically explain the assertion. The assertion focuses on the concept of non-overlapping codes, while the reason describes the process of translation. Therefore, the reason does not serve as a direct explanation for the assertion.

4. **Choosing the Correct Option**: Based on the analysis, both the assertion and the reason are true, but the reason is not the correct explanation of the assertion. Thus, the correct answer is the second option.

**Final Answer**: Both assertion and reason are true, but reason is not the correct explanation of assertion.

---