28 terms

reproduction

STUDY
PLAY
gametogenesis
process of forming gametes through meiosis
gametes
sex cells
constitute both sperm and egg cells
spermatogenesis
occurs in male individuals
results in the formation of 4 functional spermatoza
oogenesis
occurs in female individuals
results in the formation of 1 functional ovum and 3 nonfunctional polar bodies
gestation
period of time in which all stages of development occur
fertilization
union of the sperm and egg
nucleus: formation of a zygote
implantation
attachment/penetration of the conceptus into the uterus
zygote
a fertilized ovum
sperm vehicle does not enter egg only fuse at shell membrane transferring 23 chromosomes
conceptus
stage that implants into uterus
developmental stages occurring after the zygote through two weeks
3 required events for conceptus
ovum (oogenesis)
fertilization
implantation
spermatozoa
live 12 to 48 hours
embryo
developmental stages occurring from the 3rd week through the 8th week
stage where organogenesis occurs
organogenesis
formation of specific organs in the developing embryo (one chance to form) critical stage for any type of birth defect
fetus
developmental stages occurring from the 9th week through birth.
stage of growth
for 29 weeks
or 11 weeks at gestation
identical twins
twins that develop from a single ovum fertilized by a single spermatozoa
always the same sex!
fraternal twins
twins that develop from two different ova that are fertilized by two different spermatozoa
can be same sex or opposite sex!
dizygotic (fraternal)
2 egg division
2 single zygote
2 different humans
monozygotic (identical)
1 egg division
same zygote
2 humans
2 primary sources of stem cells
adult and embryonic
stem cells
they are undifferentiated cells
they can potentially be turned into any human tissue
siamese
monozygotic split started but did not finish.
nueraltube elongation splits
2 heads
2 CNS
1 body
elephant
longest gestation
104 weeks (2 yrs)
human
gestation is 40 weeks
4 types of stem cells
totiopotent
pluripotent
multipotent
unipotent
totipotent
totus - entire
can create entire organisms
1st 3 divisions of conceptus
cloned cows
pluripotent
pluri - several/any
create parts of an organism
human organs
multipotent
multi - many/limited to subtypes
make any type of blood cells and blood cells only
unipotent
uni - one
can only make one type of cell
cells in testes