Determination of Sex

Question 1

X-inactivation results from DNA methylation and modification of histone proteins that depend on expression of the __________ gene on the inactive X

Answer 1

XIST

Question 2

Nonrandom X-inactivation can be diagnosed by analyzing ____________ of highly polymorphic X chromosomal loci

Answer 2

Methylation patterns

Question 3

In the absence of _______ expression, undifferentiated gonadal tissues develops into ovaries

Answer 3

SRY

Question 4

The _________ is important because it directs differentiation of the mesonephros and genital ridge, which are events that proceed gonadal development.

Answer 4

WT genes (11)

Question 5

Mutations on chromosomes __________ can lead to sex reversal in the presence of SRY expression

Answer 5

9,11,17

Question 6

The _________ is associated with chromosome 17.

Answer 6

SOX9

Question 7

An orphan nuclear receptor protein ___________ is associated with chromosome 9

Answer 7

Steroidogeneic factor 1, SF1

Question 8

In Dosage Sensitive Sex Reversal (DSS), ___________ leads to the development of ovaries, even in the presence of expressed SRY

Answer 8

DAX1

Question 9

Normal testes contain two important non-germ cells: _______ and _________

Answer 9

Sertoli cells and Leydig cells

Question 10

Sertoli cells produce ____________ which prevents the mullein duct derivatives

Answer 10

Mullerian Inhibitory Factor

Question 11

Leydig cells produce testosterone which stimulates the production of the _____________ into the epididymus and ductus deferens

Answer 11

Wolffian duct

Question 12

Ambiguous genitalia can occur in females following intrauterine exposure to __________ (congenital adrenal hyperplasia)

Answer 12

Testosterone

Question 13

What is the genotype of Klinefelter’s syndrome

Answer 13

47XXY

Question 14

In _________, an x-linked disorder, there is end organ unresponsiveness to androgens due to the absence/ abnormality of the cytosolic androgen receptor protein in appropriate tissues.

Answer 14

Testicular feminization

Question 15

In __________, which is autosomal recessive, there is failure of end organs to activate testosterone to DHT and results in incomplete penis development.

Answer 15

5 alpha reductase deficiency

Question 16

In _______, which is autosomal recessive, there is male psuedohermaphriditism due to a lack of testosterone.

Answer 16

Leydic hypoplasia

Question 17

In ____________, an autosomal recessive disorder, testosterone (and cholesterol) synthesis is decreased in males

Answer 17

Smith-Lemli Opitz syndrome