Question

A man with a certain disease marries a normal woman. They have eight children (3 daughters and 5 sons). All the daughters suffer from their father's disease but none of the sons are affected. Which of the following mode of inheritance do you suggest for this disease ?

 (a) Sex-linked recessive 

(b) Sex-linked dominant 

(c) Autosome dominant 

(d) Sex-limited recessive

Answer 1

Correct option (b) Sex-linked dominant

Explanation

Daughters have 2 X-chromosomes one of them is from father and other comes from mother, in this case ail the daughters are suffering from the fathers disease hence, X-chromosome of father must be carrying a dominant trait, i.e. inheritance pattern is sex-linked dominant.