In sickle cell anaemia glutamic acid is replaced by valine Which one of the following triplets codes for valine ?

Options

A. G G G
B. A A G
C. G A A
D. G U G

Explanation

To solve the question regarding sickle cell anemia and the codon for valine, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Context**:
- Sickle cell anemia is caused by a mutation in the hemoglobin gene where glutamic acid is replaced by valine at the sixth position of the amino acid sequence.

2. **Identify the Codon for Glutamic Acid**:
- The codon that codes for glutamic acid is GAG.

3. **Identify the Codon for Valine**:
- We need to find the triplet codon that codes for valine. The common codons for valine are GUU, GUC, GUA, and GUG.

4. **Determine the Correct Answer**:
- Among the options provided, we need to identify which triplet corresponds to valine. The correct triplet codon for valine is GUG.

5. **Conclusion**:
- Therefore, the answer to the question is that the triplet codon that codes for valine is **GUG**.