sex determination

Question 1

What is seminal vesicle?

Answer 1

connected to vas deferens that makes seminal fluid to nourish sperm

Question 2

What is primary gene that determines the male sex?

Answer 2

SRY

Question 3

which part of the body trigger differentiation of male or female sex reproductive tracts and genitalia, as well as differences in the brain?

Answer 3

gonads

Question 4

What syndrome consists of XO female?

Answer 4

turner’s syndrome

Question 5

what syndrome consists of XXY, males?

Answer 5

Klinefelter’s syndrome

Question 6

which of the primary sex determination genotypes have sterile phenotypes?

Answer 6

XO female and XXY male

Question 7

methods of determining sex: reptile, bird, drosophila, fish

Answer 7

temperature; ZZ male ZW female; size; XX female XO male XY male XXY female

Question 8

Y chromosome is evolved from:

Answer 8

shrinking of X chromosome

Question 9

Which gene on the Y is shared with X and pair with X during meiosis?

Answer 9

PAR

Question 10

Mutations in SRY can cause swyer’s syndrome. What is this syndrome?

Answer 10

46 XY lacking functional gonads–female anatomy but no puberty

Question 11

SRY activates transcription of a sox gene:

Answer 11

SOX9

Question 12

what is the function of SOX9:

Answer 12

directs testis development

Question 13

In the absence of SRY, what gene is transcribed instead? Where is this gene transcribed?

Answer 13

Wnt; genital ridge

Question 14

Female characteristics will form in the absence of testosterone, regardless of XX or XY. True of false?

Answer 14

True

Question 15

Primordial germ cells PGC are formed in the caudal epiblast during week 2, gastrulation, of development. What is its main function?

Answer 15

promote gonad development. testes in males and ovaries in females

Question 16

formation of kidneys:

Answer 16

formed by intermediate mesoderm.
rostral most region beginning with pronephrons
pronephrons extend caudally–> metanephric duct and tubules
pronephrons degenerate
metanephrons form at most caudal of metanephric duct
metanephrons form the kidneys
metanephric duct degenerates

Question 17

genital ridge forms the gonad, which proliferate to form the:

Answer 17

primitive sex cords

Question 18

The Mullerian duct is also formed in the intermediate mesoderm. What is its function?

Answer 18

form ovarian ducts in females but degenerate in males

Question 19

The seminiferous tubules in the testes contain a type of cells that nourish PGC:

Answer 19

sertoli cells

Question 20

Which cells are responsible for testosterone production and formed by mesenchyme?

Answer 20

leydig cells

Question 21

testosterone maintains mesonephric ducts. What are the ducts?

Answer 21

efferent duct, epididymis, vas deferens

Question 22

Sertoli cells secrete a hormone that degenerates the mullerian duct. What is it?

Answer 22

anti-Mullerian hormone

Question 23

Mesenchyme forms what type of cells that are responsible for oestrogen production?

Answer 23

Thecal cells

Question 24

The mesonephric degenerates, unlike in males, and the Mullerian duct forms which structures in the female RS?

Answer 24

oviducts, uterus and vagina

Question 25

Development of genitalia occurs at 7th week. how does the male genitalia develop?

Answer 25

urogenital folds fuse and genital tubercle elongates to form penis.
invagination of ectoderm glans form distal urethra
labioscrotal folds form the scrotum

Question 26

how does the female genitalia develop?

Answer 26

genital tubercle folds inferiorly to form clitoris
urogenital folds form labia minora
labioscrotal folds form the labia majora

Question 27

What is hypospadias?

Answer 27

urethral folds incomplete, so urethra opens along inferior aspect of the penis

Question 28

which enzyme is needed to convert testosterone into dihydrotestosterone?

Answer 28

5-alpha-reductase

Question 29

What is androgen insensitivity syndrome?

Answer 29

genetically XY males with prenatal feminization, ranging fromambiguous genitalia to full female appearance. recessive mutations.

Question 30

Describe dihydrotestosterone.

Answer 30

3 times more potent than testosterone
essential development for male genitalia in foetus
involved in male pattern baldness
involved in prostate hyposplasia/cancer

Question 31

What happens with 5-alpha reductase is inhibited?

Answer 31

do not produce DHT
no external male genitalia but have testes
adults have little facial hair, never grow acne, never go bald and small prostate
inhibition of 5-alpha reductase is used to control prostate size.

Question 32

XY individuals produce testosterone, with testes, external genitalia and vagina, no female reproductive ducts are people who have what syndrome?

Answer 32

androgen insensitivity syndrome