In sickle cell anaemia, there is change in amino acid in `beta` chain at position

Options

A. VI
B. VII
C. IX
D. X

Answer

### Step-by-Step Solution:

1. **Understanding Sickle Cell Anemia**: Sickle cell anemia is a genetic disorder that affects hemoglobin, the protein in red blood cells responsible for carrying oxygen. It is primarily caused by a mutation in the gene that encodes the beta chain of hemoglobin.

2. **Identifying the Mutation**: The specific mutation in sickle cell anemia involves a change in the DNA sequence that leads to a change in the amino acid sequence of the beta chain of hemoglobin.

3. **Locating the Amino Acid Position**: The question asks for the position of the amino acid change. In sickle cell anemia, the mutation occurs at the 6th position of the beta chain.

4. **Determining the Amino Acids Involved**: At this 6th position, the normal amino acid, glutamic acid, is replaced by valine due to a single nucleotide substitution in the gene.

5. **Conclusion**: Therefore, the answer to the question is that in sickle cell anemia, there is a change in the amino acid in the beta chain at position **6**.