While proposing double helical structure for DNA, Watson and Crick proposed scheme for

Options

A. RNA transposition
B. DNA replication
C. DNA repair
D. Translation

Answer

**Step-by-Step Solution:**

1. **Understanding the Question:**
The question asks about the scheme proposed by Watson and Crick while they were describing the double helical structure of DNA.

2. **Identifying the Options:**
The options provided are:
- Option 1: RNA transposition
- Option 2: DNA replication
- Option 3: DNA repair
- Option 4: Translation

3. **Analyzing Each Option:**
- **RNA Transposition:** This refers to the movement of RNA molecules, which is not related to the structure of DNA.
- **DNA Replication:** Watson and Crick proposed the semi-conservative model of DNA replication, where each strand of the original DNA serves as a template for the new strand.
- **DNA Repair:** This is a process that occurs after DNA has been damaged, not directly related to the structure of DNA.
- **Translation:** This is the process of synthesizing proteins from RNA, which does not pertain to the structure of DNA.

4. **Selecting the Correct Answer:**
Based on the analysis, the correct answer is **Option 2: DNA replication**. This is because Watson and Crick's model of DNA structure directly supports the semi-conservative mechanism of DNA replication.

5. **Explanation of DNA Replication:**
In the semi-conservative model, each of the two strands of the original DNA molecule serves as a template for the creation of a new complementary strand. This results in two DNA molecules, each containing one original strand and one newly synthesized strand.

6. **Base Pairing:**
The bases in the DNA strands pair specifically (adenine with thymine, and guanine with cytosine), which is crucial for the accurate replication of DNA.