A colour blind male marries a normal female.What percentage of male children of this couple will be colour blind?

Options

A. 0
B. 0.25
C. 0.5
D. 0.75

Answer

To solve the question of what percentage of male children of a colorblind male and a normal female will be colorblind, we can follow these steps:

### Step 1: Understand the Genetics of Colorblindness
Colorblindness is a sex-linked recessive trait located on the X chromosome. This means that males (XY) have only one X chromosome, while females (XX) have two. A male will express colorblindness if he has the recessive allele on his single X chromosome.

### Step 2: Determine the Genotypes of the Parents
- The colorblind male has the genotype X^cY, where X^c represents the X chromosome with the colorblind allele.
- The normal female can either be homozygous normal (XX) or a carrier (X^cX). However, since the question specifies a normal female without indicating that she is a carrier, we will assume she is homozygous normal (XX).

### Step 3: Set Up the Punnett Square
We will set up a Punnett square to determine the possible genotypes of the offspring. The male can contribute either X^c or Y, while the female can contribute either X or X.

| | X (from mother) | X (from mother) |
|---------|------------------|------------------|
| X^c (from father) | X^cX (carrier female) | X^cX (carrier female) |
| Y (from father) | XY (normal male) | XY (normal male) |

### Step 4: Analyze the Results
From the Punnett square, we can see the possible offspring:
- 50% will be female carriers (X^cX)
- 50% will be normal males (XY)

### Step 5: Determine the Percentage of Colorblind Male Children
Since the only males produced (XY) are normal, the percentage of male children that will be colorblind is 0%.

### Final Answer
The percentage of male children of this couple that will be colorblind is **0%**.

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