Question

If a colourblind woman marries with a normal man. The offsprings produced will be:

• A. All offspings will be colourblind
• B. All daughters will be normal and all son will be colourblind
• C. All offsprings will be normal
• D. All daughters will be colourblind and all sons will be normal

Answer 1

The correct option is B All daughters will be normal and all son will be colourblind

Colourblindness is an X-linked recessive disorder. One copy of the affected gene in males in each cell is sufficient to cause the disorder ($X^{c}Y$).

Females with two copies of the affected gene show the disorder ($X^c{X}^c$). Females heterozygous ($X^{c}X$) for this trait are normal but serve as a carrier of the disease.

When a colourblind woman marries a normal visioned male, daughters will be normal but will serve as carrier for the disease and all sons will be colourblind.