Q7 of 71 Page 40

Based on your understanding of genetic code, explain the formation of any abnormal haemoglobin molecule. What are the known consequences of such a change?

1. This abnormal haemoglobin molecule formation occurs because one codon GAG gets replaced by GUG. Which means in the codon GAG adenosine gets replaced by uracil.

2. This change leads to the incorporation of valine in the beta haemoglobin chain instead of Glutamic acid at the 6th position. This mutation changes the shape of red blood cell from disc shaped to sickle shape that is why it is also known as Sickle cell anaemia.


3. These sickle shaped blood cells have shorter life span than the normal blood cells. Sometimes they also get stuck in the arteries and causes blockage in the blood flow.


4. The following change may cause the death of the individual before attaining maturity.


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