13.1

Question 1

Distinguish between sex chromosomes in Drosophila males and females

Answer 1

o X chromosomes: have the eye color gene
o Y chromosomes: don’t have the eye color gene
o Males have an X and a Y chromosome, females have two X chromosomes

Question 2

Understand how sex chromosomes pair during meiosis

Answer 2

o X and Y chromosomes behave as a homologous pair

Question 3

Describe sex-linked inheritance in Drosophila using monohybrid and test crosses.

Answer 3

Practice monohybrid cross with sex-linked traits

Question 4

Describe the relationship between sex chromosomes and sex determination in humans.

Answer 4

o Xy- male (requires sry gene for “maleness”)
o XX-female (is “default”)

Question 5

Distinguish between X-linked inheritance in males versus females

Answer 5

Certain genetic diseases affect males to a greater degree than females because they only have 1 x chromosome. Females must so they are more likely to be carriers rather than affected by said diseases.

Question 6

Explain the genetic consequences of dosage compensation in mammals.

Answer 6

X inactivation causes one x chromosome to be condensed into a barr body. Causes heterozygous females to be mosacis

Question 7

List the exceptions to chromosome theory inheritance

Answer 7

Maternal inheritance- mitochondria and chloroplasts genes are passed down by mom