Oo genesis

Question 1

What is oogenesis

Answer 1

formation of the female gamete

Question 2

What does oogenesis start from

Answer 2

Undifferentiated primordial germ cell

Question 3

How many copies of chromosomes do primordial germ cells have?

Answer 3

2 copies (diploid)

Question 4

What are diploid cells

Answer 4

2 homologs of each chromosome, one from each parent

Question 5

What must happen prior to fertilization for the diploid cell to be produced

Answer 5

number of chromosomes must be reduced, haploid cells must be made

Question 6

What happens during mitosis

Answer 6

two identical cells are produced

Question 7

What are the 5 stages of prophase 1

Answer 7

Leptotene
zygotene
pachytene
diplotene
diakinesis

Question 8

What happens during Leptotene

Answer 8

chromosomes appear as thin threads

Question 9

What happens during zygotene

Answer 9

Condensation of threads

Synapsis directed by the synaptonemal complex

Question 10

What happens during pachytene

Answer 10

genetic rcombination

Question 11

What hapens during diplotene

Answer 11

Homologs start to separate

Question 12

What happens during diakinesis

Answer 12

centromers move away from each other

Question 13

What happens during metaphase 1

Answer 13

homologs align equidistant to each other

Question 14

What happpens during anaphase 1

Answer 14

Homologs are separated

Question 15

What happens during telophase 1

Answer 15

two daughter cells are formed

Each daughter cell contains one copy fo the homologous chromosomes

Question 16

How do oogoni multiply

Answer 16

Mitosis

Question 17

When is meiosis arrested

Answer 17

Late diplotene stage (dictyate)

Question 18

When does meiosis resume

Answer 18

until activation of the oocyte in response to ovulatory gonadotropic stimulus

Question 19

What is a primoridal follicle

Answer 19

oocyte enclosed by single layer of pregranulosa cells

Question 20

When is the 2nd meiotic division arrested

Answer 20

metaphase 2

Question 21

when does the 2nd meiotic division resume

Answer 21

fertilization

Question 22

What is folliculogenesis

Answer 22

formation of an antral follicle starting from a primordial follicle

Question 23

what is a follicle

Answer 23

oocyte surrounded by somatic cells

Question 24

Do primary and secondary follicles need gonadotropins

Answer 24

no

Question 25

What does development beyond secondary follicles require

Answer 25

gonadotropins

Question 26

What does FSH do

Answer 26

stimulate follicular growth

Question 27

what does LH do

Answer 27

maturation of oocyte

triggers ovulation

Question 28

What is the two cell two gonadotropin hypothesis

Answer 28

LH: Theca cell turns cholesterol to androgen
FSH: Granulosa cell, turns androgen into estrogen

Question 29

What is the only positive feedback loop

Answer 29

Estrogen on the hypothalamus/GnRH once it reaches threshold

Question 30

What happens when estrogen reaches threshold

Answer 30

Burst of GnRH
Surge of LH
follicular maturation and ovulation

Question 31

what does the LH surge do to meiosis

Answer 31

causes it to resume (first polar body extruded)

Question 32

what do the theca cells do after the LH surge

Answer 32

produce low levels of progesterone

Question 33

What happens to progesterone levels during CL formation

Answer 33

slowly increase

Question 34

What is progesterone required for

Answer 34

maintenance of pregnancy

Question 35

What causes the CL to regress in large animals

Answer 35

PGF2alpha

Question 36

What does the CL become after its destruction

Answer 36

corpus albicans