Using a punnett Square explain why males are affected more often than females by sex linked genetic disorders?

Answer 1

This is a very short compared to the X chromosome with which it is pair. In X-linked genetic disorders (such as Duchenne's muscular dystrophy}.

In the x an y type of sex determinate organisms, the genes affecting the expression are only located on X-chromosome, the y chromosome does not have its contrasting allelic gene. Hence, when a female organism has a recessive gene(for example colorblindness), its another X chromosome obtained from male gamete will mask the expression, and the female will escape color blindness. In case of male, the x-chromosome carrying a gene for colorblindness from its mother will have its expression because its counterpart (y-chromosome) does not carry its allelic form. Hence although the genes cause defects are carried by females, the males are affected more. This can be explained by drawing a Punnett Square for male and female gametic fusion possibilities.