repro 1

Question 1

sex determination

Answer 1

22 pairs of autosomes

1 pair of sex chromosomes

23 pairs of chromosomes

Question 2

abnromal sex chromosome distribution

Answer 2

non-disjunction: improper seperation

disomic gamete: improper seperation

nullisomic gamete: missing

Question 3

XXY

Answer 3

klinefelter’s

Question 4

X

Answer 4

turners” syndrom

Question 5

Y

Answer 5

not viable

Question 6

XXX or XYY

Answer 6

undiagnosed

Question 7

bipotential

Answer 7

6th week embryo

has gonads, kidneys, cloacal duct and wolffian dict, mullerian duct

if female:
-gonad (cortex) forms ovary
-gonad (medualla) regresses
-wolffian duct regresses (test absent)
-mullerian duct becomes fallopiantube, uterus, cervix, and upper vagina

if male:
-gonad (cortex) regresses
-gonad (medualla) forms testes
-wolffian duct forms vas deferens and seminal vessicle
-mullerian duct regresses (AMH present)

Question 8

SRY gene

Answer 8

sex determining region of the Y chromosome

this produces the testis determining factor (3)
1. SOX9
2. WT1
3. SF1

Question 9

Leydig cells and Sertoli cells

Answer 9

Anti-mullerian hormone (sertoli cells): causes mullerian ducts to regress

Testosterone (leydig cells): converts wolffian ducts into male accessory structures (epididymis, vas deferens, and seminal vesicles)

Dihydrotestosterone (leydig cells): differentiation of exteral genitalia pp

Question 10

development of external genitalia

Answer 10

if female:
-genital tubercle forms clit
-urethra folds form labia and vagina opening
-labioscrotal swellings form labia majora

if male: (driven by DHT dihyrotestosterone)
-genital tubercle forms penis head
-urethra fold forms shaft of penis
-labioscrotal swellings form shaft and scrotum