Colour Blidness : It is a sex-linked disorder due to defect in either red or green cone of eye resulting in failure to discriminate between red and green colour. This defect is due to mutation in certain genes present in the X chromosome. It occurs in about 8 per cent of males and only about 0.4 per cent of females. This is because the genes that lead to red-green colour blindness are on the X chromosome.( Answer questions 1 to 5)

Rahul and Shipra are husband and wife and both are suffering with colour blindness. What is the chance that their daughter will have colour blindness?(question 3)

100%

Option 2 is correct . 100%

Colour blindness is a genetic disorder that is inherited in an X-linked recessive pattern. This means that the gene responsible for colour vision is located on the X chromosome, and males have only one X chromosome, while females have two X chromosomes.

If both Rahul and Shipra are colour-blind, they must have inherited the X-linked recessive gene for colour blindness from their parents. As a result, both of them must have the genotype "XcY" (where "Xc" represents the recessive gene for colour blindness and "Y" represents the male sex chromosome).

When they have a daughter, she will inherit one X chromosome from Rahul and one X chromosome from Shipra. Since both Rahul and Shipra have only the Xc allele, the daughter will inherit one Xc allele from each of them. Therefore, the daughter's genotype will be "XcXc".

As a carrier of the recessive allele, the daughter will be a colour-blind female, as the Xc allele is dominant over the normal colour vision allele in females.

Therefore, there is a 100% chance that their daughter will have colour blindness.