Lecture 1 Flashcards
formation of haploid gametes
gametogensis
formation of sperm
spermatogenesis
explain spermatogenesis
primordial germ cell spermatogonia- mitotic division primary spermatocyte- meiosis I secondary spermatocyte- meiosis II spermatid- loss of residual bodies- make shape spermatozoa
Mother cells that help sperm development
sertoli cells
cells that produce testosterone, live outside sertoli cells
interstitial cells
primitive sustentacular cells that develop a lumen are called
seminiferous tubules
parts of sperm
head - acrosome, haploid nucleus
Tail
-neck- mitochondria
-middle piece- flagellum 2 to 9 formation
explain oogenesis
PRIMORDIAL GERM CELL- gets surrounded by follicular cells
OOGONIA- enters meiosis I stops at diplotene prophase
PRIMARY OOCYTE- (2N) follicular cells now called granulosa cells -whole thing called primordial follicle
PRIMARY FOLLICLE- granulosa cells become cubodial
SECONDARY FOLLICLE- STARTS AT PUBERTY- many layers of granulosa
SECONDARY FOLLICLE- antrum, cumulus oophorus and ZP forms
TERTIARY FOLLICLE- at menstration: cell restart meiosis I splits into daughter cell (1N) and polar body. oocyte is ovulated from ovary leaving granulosa behind
SECONDARY OOCYTE- sperm entering triggers Meiosis II, creates haploid daughter cell and polar body, daughter cell will go through mitosis with sperm
combination of two haploid gametes fuse to make a genetically unique individual
fertilization
group of cells that hold oocyte in center of follicle
cumulus oophorus
another name for cumulus oophorus
corona radiata
term for many sperm getting into egg
polyspermy
what does ZP do
- helps sperm and egg binding
- block polyspermy
- maintaining pre implantation embryo structure- stays until granulation hatching
- prevents premature implantation
explain acrosome reaction
when sperm binds to ZP digestive proteins, hyaluronidase and acrosin, are released and help break down the ZP which allows sperm to get into egg
name the digestive proteins in acrosome reaction
hyaluronidase and acrosin
explain sperm getting to egg
- sperm reach ZP
- acrosome reaction digests ZP
- plasma membrane of sperm and egg fuse- increase in Ca2+ causes egg to complete meiosis II
- cortical granules are released from egg and change ZP to prevent polyspermy
- sperm enters egg
the release of ___ causes the egg to complete meiosis II. this process is called ____
Ca2+
oocyte activation
explain cortical reaction
- cortical granules live inside membrane of egg in vesicles
2. when sperm binds to plasma membrane of egg, granules are released and change ZP, preventing polyspermy
what is the ZP made of
made of 3 gycoproteins: ZPA, ZPB and ZPC
When cells divide in the absence of large amount of yolk
holoblastic cleavage
when cells divide in the presence of a large amount of yolk
meroblastic cleavage
types of holoblastic cleavage
bilateral, radial, spiral and rotational
type of meroblastic cleavage
discoidal and superficial