Sex determination

Question 1

What are the chromosomes for female

Answer 1

XX

Question 2

What are the chromosomes for males

Answer 2

XY

Question 3

Where do we begin to see cell differentiation in the fetus

Answer 3

at about 6 weeks, the fetus will start ti exhibit bipotential primordium

Question 4

What happens to the development of the structures in the fetus if it is a female

Answer 4

1. the gonadal cortex will turn into the ovary
2. The absence of testosterone causes wolffian duct to regress and
3. the Müllerian duct becomes the fallopian tube, uterus, and vagina

Question 5

What is about the Y chromosome that will cause a male to develop

Answer 5

the Y chromosome contains a SRY gene that promotes testes development

Question 6

SRY

Answer 6

encodes a transcription factor for testes development

Question 7

What is the role of SOX9 in testes development

Answer 7

when the fetus has XY, Transcription factor- SF1 will stimulate SRY which releases SOX9 that will stimulate AMH- anti-mullerian hormone that represses mullein development

Question 8

What is the role of SOX9 in gonadal development

Answer 8

in XY fetuses, SOX9 represses beta-catenine

In XX fetuses, beta-catenine suppresses SOX9

Question 9

How does SOX9 contribute to testes formation

Answer 9

it initiates Sertoli cells differentiation

by proliferation, migration, organization, vascularization, and leydig cell differentiation

Question 10

What happens to the development of the structures in the fetus if it is a male

Answer 10

Gonadal cortex suppresses
gonadal medulla forms into testes
wolffian duct form into epididymis, seminal vesicle, and vas deferens
mullerian duct represses

Question 11

What will happen to the internal, external, and hormone levels for an XY individual with androgen insensitivity (no androgen-no testosterone)

Answer 11

internal: testes will be undescended

external: vagina with closed hole

hormones: high androgens and LH