CBSE Class 12-science Answered

Baldness is a sex-influenced trait because testosterone causes an increased expression of the trait.  

The inheritance pattern of baldness is as follows:

Male pattern baldness is dominant in human males and recessive in females.

As per the given problem,

The male is bald but his father is normal. Hence, his genotype would be X^BY.

The female has both the parents who are normal. However, there is no mention that the mother is heterozygous or homozygous.

Hence, the genotype of the female would be either X^BX^b (carrier) or X^bX^b (normal).

Case I: The progeny of the bald male and normal female: X^BY × X^bX^b  

In this case, all the daughters are normal but carriers and all sons are normal.

Case II: The progeny of the bald male and carrier female: X^BY × X^BX^b  

In this case, half the daughter are bald and half are normal but carriers. Half the sons are bald and half are normal.