Question

A single mutant allele is responsible for the abnormal formation of haemoglobin (i.e. Hbs). If it is present in a homozygous state (HbsHbs), son develops a sickle cell anemia while shows few symptoms if it is found in a heterozygous state (HbAHbs). On the basis of the above situation, work out a cross supposing a condition in which a woman’* mother homozygous for allele marries a male who is heterozygous for the allele. Indicate the probability of having a normal or a diseased child for each of her pregnancy.

Answer 1

50% Homozygous for the Hbs allele.
50% Heterozygous for both Hbs and HbA allele.
Above cross shows that a child has the equal probability of developing into a normal child or with some symptoms of the ***. This therefore, proves that a woman has no risk of giving birth to a child everytime she conceives.