A color-blind child is born to a normal couple. Work out a cross to show how it is possible. Mention the sex of this child.

Explanation

To solve the problem of how a color-blind child can be born to a normal couple, we need to understand the genetics behind color blindness, which is a sex-linked trait. Here’s a step-by-step solution:

### Step 1: Understand the Genetics of Color Blindness
Color blindness is primarily caused by a recessive allele located on the X chromosome. Males have one X and one Y chromosome (XY), while females have two X chromosomes (XX). For a male to be color blind, he must inherit the recessive allele on his single X chromosome. A female would need to inherit the recessive allele on both of her X chromosomes to express color blindness.

### Step 2: Define the Genotypes of the Parents
- **Normal Female (Mother)**: Since the mother is normal but can have a color-blind child, she must be a carrier for the color blindness allele. Therefore, her genotype is X^C X^c (where X^C is the normal vision allele and X^c is the color blindness allele).
- **Normal Male (Father)**: The father is normal and does not carry the color blindness allele. His genotype is X^C Y.
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