Class 12 NEET Biology Principles of Inheritance and Variation Questions Part 1

Colour blindness is more common in men than in women because the genes responsible for the color blindness are located on the X chromosome. Males have only one X chromosome whereas females have two X chromosomes. In males, only one defective X chromosome is enough to cause colour blindness. In females, two defective X chromosomes are required to cause colour blindness. This type of inheritance pattern is called X-linked inheritance and it primarily affects males.