everyday science MCQ #3127

If a colour-blind lady marries a normal male and gives birth to a son and a daughter, then:

everyday science MCQ #3127

  1. Question 1

    Q1. If a colour-blind lady marries a normal male and gives birth to a son and a daughter, then:

    • A) Both son and daughter would be colour-blind
    • B) The daughter would be colour-blind but the son would be normal
    • C) The son would be colour-blind but the daughter would be a heterozygous normal
    • D) Neither the son nor the daughter would be colour-blind

    Answer: The son would be colour-blind but the daughter would be a heterozygous normal

    Explanation: A colour-blind mother (X^c X^c) × normal father (X^N Y): all sons receive X^c from mother and Y from father, making all sons colour-blind; all daughters receive X^c from mother and X^N from father, making them carriers (heterozygous normal).