Q. In which of the following, there is no defect in the sex chromosome?

A) Turner’s syndrome
B) Down’s syndrome
C) Colour blindness
D) Klinefelter’s syndrome
Explanation

Down’s syndrome (Mongolian idiocy) is a congenital disorder caused by trisomy of chromosome-21, often by non disjunction.

Dr. Abubacker
Reviewed by Dr. Abubacker

Physics Educator & NEET/JEE Specialist

Ph.D. in Physics with 19+ years of teaching experience.