Gametogenesis Flashcards
where do primordial germ cells migrate from
the wall of the yolk sac
where does genetic variation come from in meiosis
- crossing over at chiasmata in prophase 1
- independent assortment of bivalents and chromatids in metaphase
where does spermatogenesis occur
in the spaces between Sertoli cells in the seminiferous tubules
what is spermiogenesis
the differentiation of the 4 spermatids into spermatozoa
what is spermiation
the release of sperm into the seminiferous tubule lumen
when sperm are first produced they are non-motile, so how do they move to the epididymus
through peristalic contractions and due to secretions of the Sertoli cells
what is the spermatogenic cycle
the time taken to reach the same stage in spermatogenesis at a particular part of the tubule
what is the spermatogenic wave
the distance between 2 areas of the seminiferous tubules which are at the same stage of spermatogenesis
why is sperm capacitation
where sperm lose the glycoproteins and cholesterol surrounding the membrane around the head
why does sperm capacitation occur
to allow the sperm to penetrate the zone pellucida
what is a primordial follicle
when the primary oocyte is surrounded in a single layer of flat cells called follicular cells
what are the 3 stages of development that the primordial follicle undergoes
- preantral
- antral
- preovulatory
what happens in the preantral development stage
the surrounding follicular cells change to a strafed cuboidal surrounding called granulose cells
what do granulose cells do
secrete a glycoprotein covering to produce the bona pellucida
what happens in the antral stage of development
fluid filled spaces around the granulose cells form and fuse to form the Antrum
