Zoology - Molecular Basis of Inheritance Question with Solution | TestHub
Assertion : Only a boy child could be born with a substitution of glutamic acid by valine on codon of beta-chain of haemoglobin. Reason : The gene for the above mutation is found on Y-chromosome.
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Sickle cell anaemia is an autosomal recessive hereditary disorder in which the erythrocytes become sickle-shaped under oxygen deficiency as during strenuous exercise and at high altitudes. The disorder or disease is caused by the formation of an abnormal haemoglobin called haemoglobin-S. As found out by Ingram (1958), haemoglobin-S differs from normal haemoglobin-A in only one amino acid amino acid of -chain, glutamic acid, is replaced by valine due to substitution (transversion) of by A in the second position of the triplet codon (CTC) which is changed to CAC in the -haemoglobin gene situated on chromosome 11.
