Exams › NEET › Biology

A woman with normal vision, but whose father was colour blind, marries a colour blind man. Suppose that the fourth child of this couple was a boy. This boy

1. may be colour blind or may be of normal vision
2. must be colour blind
3. must have normal colour vision
4. will be partially colour blind since he is heterozygous for the colour blind mutant allele

Correct answer: must be colour blind

Solution

Colour blindness is typically X-linked recessive. A woman with normal vision whose father was colour blind must be a carrier, and a colour-blind man passes his Y chromosome to sons, not his affected X. So any boy must receive the mutant X from his mother and be colour blind.

Related NEET Biology questions

• Pea plants were more suitable than cattle for Mendel's experiment because
• Identify the wrong statement about meiosis.
• Which condition of zygote cell will lead to birth of a normal human female child
• A human zygote has
• DNA in the offsprings is contributed by
• A common test to find the genotype of a hybrid is by

⚔️ Practice NEET Biology free + battle 1v1 →