Fertilization and Gametogenesis Flashcards
how many days does sperm survive in a woman’s body
3 days
egg cell must be fertilized within
12-24 hours
changes that occur between the sperm and ovum, allowing only one sperm to penetrate the ovum
capacitation
steps in fertilization:
[JVP]
(1) Jelly coat
(2) Vitelline envelope
(3) Plasma membrane fuse
this needs to be penetrated in order for the sperm to fuse with the oocyte
corona radiata
contains digestive enzymes to eat away the jelly layer
acrosome cap
species-specific boundary involved in sperm-egg recognition
vitelline envelope
what disappears and appears when egg and sperm plasma membrane fuse?
ovum disappears
pro-nuclei (two sets of chromosomes) appear
mitotic division of a zygote into a morula
cleavage
ball of cells that form a blastula that implants in the uterus
morula
termed as primitive germ cells; surrounded by a single layer of flat follicular cells
primordial follicle
arrested stage; does not complete meiosis I until after puberty; several layers of granulosa cells; theca folliculi; zona pellucida
primary follicle
found between the primary oocyte and granulosa cell
zona pellucida
theca interna; theca externa; antrum; corona radiata
secondary follicle
cavity filled with follicular fluid produced by granulosa cells
antrum
occurs before ovulation; diploid before it undergoes mitosis to become two haploids of unequal size
mature follicle
two haploid cells
first polar body
secondary oocyte
discarded nuclear material
first polar body
undergoes meiosis II and stops at metaphase II
mature follicle
if the secondary oocyte is not fertilized, what happens
menstruation occurs
if the secondary oocyte is fertilized, what happens?
meiosis II resumes
initiates follicular growth and secretion of estrogen; needed to form oocyte
FSH
promotes the formation of corpus luteum; stimulates the production of estrogen, progesterone, relaxin, and inhibin
LH
stimulates further development of ovarian follicles
LH
inhibits the secretion of FSH and stops the production of LH
inhibin
stages of embryogenesis
fertilization -> zygote -> morula -> blastocyst -> embryo
results of fertilization:
determination of sex
reassociation of male and female sets of chromosomes to full diploid number
activation of ovum into cleavafe
stages of prenatal development:
(1) pre-embryonic period
(2) embryonic period
(3) fetal period
amniotic cavity forms between the inner cell and zygote during what week
2nd week
occurs third to eighth weeks when all manor organ systems begin to develop
embryonic period
when does fetal period end?
at birth
fertile men
63% moving soerm
more than 12% normal sperm shape and structure
infertile men
below 13.5 m sperm count
>32% sperm motility
>9% normal sperm appearance
habits that can induce sperm count
testicular overheating
emotional stress
entrance of multiple sperm
polyspermy
what occurs during polyspermy
fast change of electrical potential of egg plasma membrane,
egg releases all of their Ca ions (sperm confusion) - sperm will not enter
the lower yolky portion of the egg; opposite of the animal hemisphere
vegetal hemisphere
implantation starts when
blastocyst attached to the endometrium
what produces HCG
Trophoblast of the blastocyst
