In human, attached earlobes are a dominant feature over free earlobes while hypertrichosis (Y-linked) feature. A man with attached earlobed and extensive hair on pinna married a woman having free earlobes. The couple had one son with free earlobes and hairy pinna and two daughters with attached earlobes. One of the daughters with attached earlobes. One of he daughters married a man with free earlobes and sparse hair on pinna. They had two sons. What would be the characteristics of their ponnae ?

Options

A. Both will have attached earlobes and sparse hair on pinna
B. There would be equal chances foe both having free or attached earlobes and sparse hair on pinnae
C. They would have hairy pinnae and there would be 1 and 8 chance that both will have attached earlobes
D. Both will have free earlobes and extensive hair on pinnae.

Answer

B

Explanation

It is given that attached earlobes are a dominant feature hence, we can represent it as LL or Ll. Also, hypertrichosis of the ear is a Y-linked feature and thus we can representy is as `Y^(th)`. Now, according to the given information following crosses can be made

Thus, there would be equal chances for both daughters and sons to have free earlobe (ll) or attached (Ll) earlobe adn sparse hair on pinna.