Very important question Ritul 👍
Colour blindness is a condition, in which certain colours (green or red) cannot be distinguished, due to the lack of one or more colour absorbing pigments in cells of retina.
In humans, the most common colour blindness is
red-green colour blindness, which is a sex linked
(i.e. X-linked recessive) defect caused by a recessive gene and is thus more common in males than females.
The symbols needed to follow this allele through a Punnett square are:
(a) X = X-chromosome carrying the normal (dominant) allele.
(b) Xc= X-chromosome carrying the defective (recessive) allele.
(c) Y = Y-chromosome, with no allele for this gene on it.