A spontaneous mutation results in a couple having only female progeny. When the doughter marries and has childeren, non of them are males. However , in the third generation there are few male offspring . What is the most likely ex planation of this observation-

Options

A. The mutation reverse spontaneously in the third generation
B. The mutation occurs on the X chromosome and is both recessive and lethal
C. The mutation occurs on the X chromosome and is both recessive and dominant
D. The mutation occurs on an autosome and is dominant

Answer

B

Explanation

The mutation that occurred in on x-chromosome and is both recessive and lethal since, female is carrier it survives but due to hemizygous condition male is unableto survive.
`XY^(m)rarr` carrier (survives)
`X^(m)Yrarr` dies
While in third generation, the possibility of male child occurs.