repro 2

Question 1

gametogenesis

Answer 1

-the production of gametes

1. starts with germ cells in embryonic gonades undergo mitotic divisions to increase number
2. duplication of chromosomes (92) chromosomes
3. one primary gamete divides into two secondary gametes (each with 46 chromosomes)
4. secondary gametes divide again to produce haploid gametes (23 chromosomes=23 chromotids)

Question 2

female gametogenesis (oogenesis)

Answer 2

-> oogonium

Mitosis

-> primary oocyte

meiosis

-> first polar body (dies)
-> secondary oocyte (meiosis if fertilized)

meiosis

one primary oocyte yields 1 egg. second polar body forms zygote

Question 3

male gametogenesis (spermatogenesis)

Answer 3

spermatogonium

mitosis

spermatocyte

meiosis

2 secondary spermatocytes

meiosis

4 spermatatids

Question 4

brain directing reproduction

Answer 4

begins in hypothalamus and pituitary gland that control gondal secretion of sex hormones including androgens, estrogen, and proestrogen

95% of anrogen in testes 5% in adrenal cortex

Question 5

control pathways

Answer 5

in hypothalamus there is a hormone (GnRH) that is produced whivh controls the secretion in pituitary of LH and FSH that act on the gonads

Question 6

control pathways (Hypophyseal portal system)

Answer 6

neurons in hypothalamus sythesize neurohormones and realse them into capillary bed (portal viens) which goes into anterior pituitary which then stimulates endocrine cells to release their hormones to the rest of the body

Question 7

long and short pathways

Answer 7

LH and FSH from pituitary makes hypothalamus stop making GnRH

high levels of estrogen is posititive feedback

Question 8

is the release of GnRH pulsatile

Answer 8

yes. spikes every 1-3 hourse in both sexes

-must be released pulses or else the receptors will desenitize (important during puberty)

-females also have a surge of GnRH corrosponding with ovulation