Question

explain how a difference in the sequence of nucleotides in a gene could result in one of these boys being albino and the other boy having normal skin and hair color

Answer 1

Albinism is a recessive trait characterized by an absence of pigment melanin responsible for skin and hair color. Actually, albinism is caused by a defect in gene for enzyme which synthesizes melanin. The central dogma of molecular biology explains that the sequence of DNA specifies the sequence of mRNA, which, further, specifies codes for the sequence of proteins. Since a gene is a segment of DNA, altered gene will cause altered mRNA which will cause altered protein. Thus, defect in gene for enzyme which synthesizes melanin will cause the absence of melanin and consequently, albinism.