Answer to Question #162279 in Biology for Anas

Question

solve this problem: Unicornism is an X linked recessive trait. A normal man marries a normal woman and they have many children. 

 

They have normal and unicorned boys, and all the girls are normal.

 

Using a punnet square and also showing the genotypes of the parents and children explain how this can happen .

Answer 1

Since the man and woman have unicorned boys and the man is normal, the woman is heterozygous and is a carrier of the recessive trait. As a result, a male genotype is X^uY and a female genotype is X^UX^u. The parents produce the possible gametes:

Male: X^uY;

Female: X^U and X^u.

The genotypes of their children are shown in the Punnett square:

As a result, all girls have dominant allele and are healthy while boys with recessive allele are unicorned.