Question

Inheritance of total colour-blindness is

• A. X-linked
• B. XY-linked
• C. Y-linked
• D. None of the above

Answer 1

Answer: (A)

Traits that are determined by alleles carried on the X chromosome are called as X-linked inheritance. One example of an X-linked trait is red-green colorblindness. Let (Xc) represent the recessive allele that causes colorblindness and (X+) represent the normal dominant allele. Females that are X+X+ or X+Xc have normal color vision, while XcXc females are colorblind. Males that are X+Y have a normal color vision while XcY males are colorblind. Thus, option A is correct and other options are wrong.