Question

Generally, the recessive character is expressed only when present in a double recessive condition i.e. homozygous condition. However, a single recessive gene can express itself in human beings when the gene is present on ______

Options

• the 21^st-chromosome of the male

• the X-chromosome of the male

• any autosome

• the X-chromosome of the female

Answer 1

Generally, the recessive character is expressed only when present in a double recessive condition i.e. homozygous condition. However, a single recessive gene can express itself in human beings when the gene is present on the X-chromosome of the male.

Explanation:

Because the XX complement is present in females, the recessive gene is silenced by the dominant gene, whereas the Y-chromosome is present in males, allowing the recessive gene on the X-chromosome to express itself.