Question

In the XX–XY sex determination system, if a female (XX) is fertilized by an X-bearing sperm, what is the resulting genotype of the offspring?

Options

• XXY (female)

• XX (female)

• XO (male)

• XY (male)

Answer 1

When an X-bearing sperm fertilizes an egg from a female (which always carries an X chromosome), the resulting offspring has the XX genotype and develops as female. Conversely, if a Y-bearing sperm fertilizes the egg, the resulting XY genotype develops as male. The male parent's sperm determines the sex of the offspring in this system.