Select the correct bases of DNA RNA and amino acid of beta chain causing sickle cell anaemia

Options

A. GAG-GUG
B. CAC-GTG
C. CTC-GAG
D. CAC-GTG

Answer

To solve the question regarding the bases of DNA, RNA, and the amino acid of the beta chain causing sickle cell anemia, we can break it down into several steps:

### Step-by-Step Solution:

1. **Understanding Sickle Cell Anemia**:
- Sickle cell anemia is caused by a mutation in the beta-globin gene of hemoglobin, which is located on chromosome 11. This mutation leads to the production of abnormal hemoglobin, known as hemoglobin S (HbS).

2. **Identifying the Normal and Mutated Codon**:
- The normal codon for the beta chain at the sixth position is GAG, which codes for the amino acid glutamic acid (or glutamate).
- In sickle cell anemia, this codon is mutated to GUG, which codes for the amino acid valine.

3. **Transcription to RNA**:
- The DNA sequence is transcribed into mRNA. The normal DNA sequence (template strand) corresponding to the normal codon GAG would be CTC (since DNA is complementary to RNA).
- The mutated DNA sequence corresponding to the mutated codon GUG would be CAC.

4. **Amino Acid Sequence**:
- The normal amino acid sequence at the sixth position is glutamic acid (GAG → Glu).
- The mutated amino acid sequence at the sixth position is valine (GUG → Val).

5. **Final Summary**:
- **DNA Base (Normal)**: CTC (which transcribes to GAG)
- **RNA Base (Mutated)**: GUG
- **Amino Acid (Normal)**: Glutamic Acid (Glu)
- **Amino Acid (Mutated)**: Valine (Val)

### Final Answer:
- **DNA Base**: CTC (normal)
- **RNA Base**: GUG (mutated)
- **Amino Acid (Normal)**: Glutamic Acid (Glu)
- **Amino Acid (Mutated)**: Valine (Val)