3. Extensions to Mendelian Inheritance

Which of the follow sex chromosomes can be describes as homogametic?

In the ZZ/ZW sex determination system, the male is…?

In humans, which region on the Y chromosome determines maleness?

During meiosis the XY sex chromosomes segregate independently. Which of the following represents the gametes chromosomes after meiosis?

How do we know that X chromosomal inactivation of either the paternal or maternal homolog is a random event during early development in mammalian females?

How do we know that Drosophila utilizes a different sex-determination mechanism than mammals, even though it has the same sex-chromosome compositions in males and females?

How do we know that in humans the X chromosomes play no role in human sex determination, while the Y chromosome causes maleness and its absence causes femaleness?

How do we know whether or not a heteromorphic chromosome such as the Y chromosome plays a crucial role in the determination of sex?