Q. 94.0( 1 Vote )
If a father and son are both defective in red-green colour vision, is it likely that the son inherited the trait from his father? Comment.
Colour blindness is common hereditary condition which means it is passed down from parents. Red/green colour blindness is passed from mother to son on the 23rd chromosome, which is known as the sex chromosome. The faulty gene for colour blindness is found only on the X chromosome.
When the father is colour blind, he can only pass an X chromosome to his daughter. Hence a colour blind boy cant receive a colour blind gene from his father, even if his father is colour blind. A father can only pass Y gene to his son.
Thus its clear that a son can inherit the disease only from his mother even if his father is colour blind. Because only a mother can pass X chromosome to his son.
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