oogenesis Flashcards
what is oogenesis
the formation of secondary oocytes- female gametes
when in the human life cycle does oogenesis start
before birth
when in the human life cycle does oogenesis
menopause
describe the stages of oogenesis before birth
1) before birth cells of the germinal epithelium divide by mitosis forming a diploid cell called oogonium
2) the oogonia divide more by mitosis and enlarge making diploid primary oocytes
3) the primary oocytes starts dividing by meiosis I but are arrested at prophase I
4) primary oocytes are surrounded by follicle cells forming primary follicles
describe the process of oogenesis during puberty
1) At puberty hormone FSH stimulates some of the primary follicles to develop into secondary follicles
2) the primary oocytes completes meiosis I to form a haploid secondary oocyte and a small polar body
3) the secondary follicles develops into Graafian follicle which now contains the secondary oocyte
4) the secondary oocyte begins meiosis II but stops at metaphase II
describe the ovulation stage of oogenesis
1) the Graafian follicle migrates to the surface of the ovary where it bursts projecting the secondary oocyte into the fallopian tube
2) meiosis II is only completed if fertilisation takes place forming an ovum and a second polar body
describe the events which occur after ovulation
the Graafian follicle becomes the corpus luteum- if fertilisation occurs this produces hormones, but if not it regresses
what do germinal epithelial cells in women divide into during mitosis
1) oogonia
2) follicle cells
draw and label the structure of a secondary oocyte
how many gametes are produced after oogenesis
1
what is the precise location of production in females
the germinal epithelial cells in the ovary
list accessory cells that are involved in oogenesis
follicle cells
