A colour blind male (X^cY) marries a carrier female (X^CX^c). Possible genotype of daughters will be______?

a. X^cX^c only

b. X^CX^C only

c. X^CX^C and X^cX^c

d. X^CX^c and X^cX^c

Hint: Color blindness is defined as the inability to perceive colors correctly. It is an X-linked or sex-linked recessive disorder, meaning that the disease manifests when both alleles are recessive (homozygous recessive alleles) on the X chromosome in the same cell. This condition is commonly referred to as a congenital color vision deficiency.

Complete answer: According to Mendel’s laws of inheritance, specifically the law of segregation and the law of independent assortment, allele combinations occur as follows: if a color-blind male (X^cY) mates with a heterozygous female carrier (X^CX^c), then the possible alleles of the offspring will be: X^c, Y, X^C, X^c

The potential combinations are: X^cX^C, X^cX^c, YX^C, YX^c

From these combinations, the daughter genotypes can be: X^cX^C and X^cX^c

Therefore, there is a 50% chance that the daughter will be color blind, as the genotype required for color blindness is X^cX^c. An X^CX^c daughter will be a carrier of the condition; she can pass on the trait but will not be affected by it herself. The probability ratio for the daughter to inherit the disease is 2:1.

Thus, the correct answer is option (D).

Note:

Color blindness is a condition where a person’s ability to distinguish between colors is reduced. Complete color blindness is known as achromatopsia. The Ishihara color test is a common diagnostic tool for detecting color vision deficiency, which affects about 1 in 12 men and 1 in 200 women.