Developmental Biology

Question 1

Genetic female sex is determined by the absence of

Answer 1

SRY gene

Question 2

This sex determination is determined at the time of fertilization

Answer 2

Genetic sex

Question 3

Single most consistent determinant of maleness

Answer 3

Presence of Y chromosome

Question 4

This hypothesis states that one of the 2 copies of the X chromosome present in females is inactivated

Basis of sex chromatin test

Answer 4

Lyon hypothesis

Question 5

Sex determination test that stains the hair strands with fluorescent stain

Used for large populations (Olympics) that ensures the individual joining the female division is a normal genetic female

Answer 5

Hair root test

Question 6

Sex chomatin test looks for Barr bodies while Hair root test looks for

Answer 6

Y bodies

Question 7

Most accurate method for sex determination

Answer 7

Karyotyping

Question 8

This term describes the development of primary sex organs in response to genetic sex

Answer 8

Gonadal sex

Question 9

At what week of gestation does the fetus have bipotential gonads?

Answer 9

4-6 weeks

Question 10

This cell secretes testosterone which controls the development of the Wolffian duct and development of male external genitalia through DHT

Answer 10

Leydig cells

Question 11

What hormone promotes the development of male external genitalia?

Answer 11

DHT

Question 12

What hormone promotes the development of Wolffian duct into accessory structure?

Answer 12

Testosterone

Question 13

This cell secretes anti mullerian hormone that cause the regression of the mullerian duct

Answer 13

Sertoli cell

Question 14

The testis comes from this embryonic structure

Answer 14

Embryonic medulla

Question 15

What happens to the embryonic cortex upon development of the male gonads?

Answer 15

Regresses

Question 16

Formation of Sertoli cells happens during

Answer 16

6-7 weeks

Question 17

Formation of Leydig cells occur during

Answer 17

8-9 weeks

Question 18

Secretion of testosterone of Leydig cells occurs in response to what hormone

Answer 18

HCG

Question 19

At what AOG is the definitive testes present and secretion of testosterone established?

Answer 19

9 weeks

Question 20

At what AOG does the testes descend through the inguinal ring?

Answer 20

7-9 months

Question 21

What hormone does the embryonic ovary secrete?

Answer 21

None

Question 22

The embryonic cortex in female development proliferates to become

Answer 22

Ovaries

Question 23

The ovaries reach maximal development at what AOG

Answer 23

20-25 weeks

Question 24

In female gonad development the embryonic medulla regresses and forms the

Answer 24

Hilum of mature ovaries

Question 25

When does female gonadal development start?

Answer 25

9 weeks when there is absence of signal for testis formation

Question 26

This type of sex is determined by the regulation of gonadal sex of the differentiation of the genital apparatus

Answer 26

Phenotypic sex

Question 27

Derivatives of the Wolffian duct

Answer 27

VESt Vas deferens Epididymis Seminal vesicle

Question 28

Derivatives of the Paramesonephric duct

Answer 28

``` Carey Mulligan (Mullerian) Fallopian tube Uterus Cervix Upper vagina ```

Question 29

This hormone is required for conversion of testosterone to DHT

Answer 29

5 alpha reductase

Question 30

Precursor of both external genitalia

Answer 30

Anlagen

Question 31

Genital tubercle develops into these structures in the male and female external genitalia

Answer 31

Male- glans penis, corpus cavernosum, spongiosum | Female- clitoris and vestibular bulb

Question 32

Urogenital folds become

Answer 32

Male- ventral shaft of penis | Female- labia minora

Question 33

Labioscrotal/Genital swelling becomes

Answer 33

Scrotum and prepuce | Labia majora

Question 34

The urogenital sinus becomes

Answer 34

Male urethra, Cowper, prostate gland Female urethra, lower vagina, bartholin and skene glands

Question 35

Transverse vaginal septum occurs when this structure fails to develop

Answer 35

Urogenital sinus

Question 36

The growth of the labia to normal size requires this hormone

Answer 36

Estrogen

Question 37

Control of gonadal function is mediated by these 2 gonadotropins

Answer 37

FSH | LH

Question 38

Release of gonadotropins in males are in this manner

Answer 38

Tonic

Question 39

Release of gonadotropins in females are in this manner

Answer 39

Cyclic

Question 40

This type of sex is the establishment of gender role, identity and sexual orientation

Answer 40

Psychological sex

Question 41

This type of error in sex determination occurs when there is an established defect in gametogenesis where chromosomes fail to separate and both go to one daughter cell during meiosis

Answer 41

Nondisjunction

Question 42

Most common type of Nondisjunction that leads to complete absence of one sex chromosome and monosomy

Answer 42

Turner syndrome

Question 43

Streaked ovary Short stature Shield chest Coarctation of aorta

Answer 43

Turner syndrome

Question 44

Meiotic nondisjunction that leads to testicular atrophy Eunuchoid body shape Tall, long extremities Gynecomastia

Answer 44

Klinefelter

Question 45

Genetic males whose target cells lack receptors for testosterone are feminized Male pseudo hermaphroditism

Answer 45

Androgen insensitivity

Question 46

Virilization of XX fetus Ambiguous genitalia Adrenal androgen overproduction

Answer 46

Congenital adrenal hyperplasia