Question

What is the probability of producing a colourblind son if a colourblind male marries a normal visioned female?

• A. zero
• B. \(\frac{1}{4}^{\text{th }}\)
• C. \(\frac{1}{2}\)
• D. 1

Hint:

Sons receive their X chromosome from the mother and the Y chromosome from the father.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept
Colour blindness is X-linked recessive.
Colourblind male is \(X^cY\) and a normal visioned female is \(XX\).

Step 2: Cross
Gametes of father: \(X^c\) and \(Y\).
Gametes of mother: \(X\) and \(X\).
Offspring: \(XX^c\) (carrier daughters) and \(XY\) (normal sons).

Step 3: Result
Every son gets normal X from the mother, so the probability of a colourblind son is zero.

Final Answer:
The probability of a colourblind son is zero. \[ \boxed{\text{(A) }\text{zero}} \]