Class 12th Biology 2011 Set3 Delhi Board Paper Solution
Question 24
(a) Sickle celled anaemia in humans is a result of point mutation. Explain.
(a) Sickle celled anaemia in humans is a result of point mutation. Explain.
(b) Write the genotypes of both the parents who have produced a sickle celled anaemic offspring.
Answer
a. Point mutation can be defined as the mutation caused due to the deletion or addition of a single base pair in DNA sequence. Which results in the formation of protein that deviate from its native form resulting in disease.
Sickle cell anemia is categorized as a point mutation because it results from the change in single base pair for beta globin chain. The change results in formation of valine instead of glutamate.
b. Genotype for the parents with and offspring with sickle cell anaemia will be HbA/HbS and HbA/HbA or it may be HbS/HbS and HbA/HbS
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