Question

A hereditary disease which is never passed on from father to son is

• A. Autosomal linked disease
• B. X-chromosomal linked disease
• C. Y-chromosomal linked disease
• D. None of the above

Answer 1

The correct option is B X-chromosomal linked disease

A father transmits one copy of all autosomal genes to his son; he gets the other copy from the mother. Thus, an autosomal genetic disease can be transmitted from father to his sons. Father transmits its Y-chromosome to his son and X-chromosome to his daughter. Hence, the X-linked diseases are passed from father to daughters only, never to the sons because sons never receive the X-chromosome from father; they get it from mother. Due to transmission of Y-chromosome from father to son, a Y-linked disease is always passed from father to sons; never to his daughters as they don't get the Y chromosome of the father. Correct option is B.