How do mammals, including humans, solve the 'dosage problem' caused by the presence of an X and Y chromosome in one sex and two X chromosomes in the other sex?

Write a short essay that discusses sex chromosomes as they contrast with autosomes.

Distinguish between the concepts of sexual differentiation and sex determination.

Contrast the XX/XY and XX/X0 modes of sex determination.

Describe the major difference between sex determination in Drosophila and in humans.

The phenotype of an early-stage human embryo is considered sexually indifferent. Explain why this is so even though the embryo's genotypic sex is already fixed.

What specific observations (evidence) support the conclusions about sex determination in Drosophila and humans?

An insect species is discovered in which the heterogametic sex is unknown. An X-linked recessive mutation for reduced wing (rw) is discovered. Contrast the F₁ and F₂ generations from a cross between a female with reduced wings and a male with normal-sized wings when the female is the heterogametic sex.