sex and reproduction

Question 1

methods of asexual reproduction

Answer 1

fission, fragmentation and budding

Question 2

What causes molecular switch in males

Answer 2

SOX9

Question 3

male development pathway

Answer 3

SOX9 switches off WNTA, this results in the development of testes. testes go on to produce testosterone and this drive male development

Question 4

female development pathway

Answer 4

no SOX9 is present, so WNT4 remains on. this results in the development of ovaries. ovaries go on to produce esta dio and progesterone which drive female development

Question 5

what does the metanepheric kidney develop into

Answer 5

adult kidneys

Question 6

what does the mesonephros develop into

Answer 6

embryonic kidney

Question 7

cloaca

Answer 7

the anal and urethral openings

Question 8

mullarian duct

Answer 8

oviduct in females, breaks down in males

Question 9

wolffish duct

Answer 9

vans deferens in males, breaks down in females

Question 11

summary of male hormonal control of reproduction

Answer 11

the hypothalamus produces GnRH which targets the anterior pituitary to produce LH and FSH, which target leydig cells ands Sertoli cells. leydig cells produce testosterone that act as a negative feedback k on the hypothalamus and pituitary. Sertoli cells produce inhibit and drive .

Question 12

summary of female hormonal control of reproduction

Answer 12

the hypothalamus produces GnRH which targets the anterior pituitary to produce LH and FSH. LH triggers ovulation and FSH indices follicle growth. the mature follicle acts as positive feedback to the hypothalamus and the corpus lutes, which degenerates over time) acts as negative feedback.

Question 13

blastula formation in aquatic embryos

Answer 13

cleavage follows fertilisation to partition the cytoplasm into smaller blastomeres. blastulas are clumps of blastomeres and these cells are totipotent.