Muscular dystrophy certain types is sexlinked Unfortunately

Muscular dystrophy (certain types) is sex-linked. Unfortunately, most males die by age 17. Show, through Punnett squares, how females do not get this disorder.

Solution

Muscular dystrophy is an X chromosome linked recessive trait. Males have the chromosomes XY and therefore if they have the recessive trait on their X chromosome, it gets expressed. Females on the other hand have two X chromosomes XX. Therefore the recessive trait on one chromosome will not be exhibited by the individual.

Consider the example:

Father is X^mY :where X^m is the X chromosome with the Muscular dystrophy trait.

Mother is XX

According to Punnett squares:

The Girl child gets the recessive trait on only one of the X chromosomes (X^mX) and therefore does not get this disorder.

	Father (Xm)	Father (Y)
Mother (X)	XmX	XY
Mother (X)	XmX	XY