A couple has children with the following phenotypic distribution: 50 % of their sons are colour blind and 50 % have normal vision, while 50 % of their daughters are colour blind and 50 % have normal vision. Based on this data, what are the

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A couple has children with the following phenotypic distribution: 50 % of their sons are colour blind and 50 % have normal vision, while 50 % of their daughters are colour blind and 50 % have normal vision. Based on this data, what are the most likely phenotypes of the parents?

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Correct answer: D. Mother has normal vision, Father is colour blind

Colour blindness is an X-linked recessive trait. Sons inherit their X chromosome exclusively from their mother. Since the sons show a 1:1 ratio of normal vision ( X^C Y ) to colour blindness ( X^c Y ), the mother must be heterozygous ( X^C X^c ). Therefore, the mother has normal vision but is a carrier. Daughters inherit one X chromosome from each parent. For a daughter to be colour blind ( X^c X^c ), she must receive an X^c allele from both her mother and her father. Since 50 % of the daughters are colour blind, t

A couple has children with the following phenotypic distribution: 50 % of their sons are colour blind and 50 % have normal vision, while 50 % of their daughters are colour blind and 50 % have normal vision. Based on this data, what are the most likely phenotypes of the parents?

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