Early Embryonic Devlopment Flashcards
(26 cards)
fertilized oocyte
ootid
fusion of MPN and FPN
syngamy
ootid undergone syngamy
zygote
organism in early stages of development and doesn’t have recognizable appearance of that species
embryo
identifiable organism in uterus
fetus
in ootid, what is visible
- both PB
- both PN
PN=
pronuclei
in zygote what do you see
- single diploid (2n) nucleus
mitosis begins with and in what structure
zona pellucida
cleavage
mitotic divisions
individual cells that form during early embryonic devolvement
blastomeres
totipotent
ability to give rise to an individual (twins)
what blastomeres are considered totipotent
blastomeres from embryos less than 16 cells
morulla
ball of cells after 8-cell stage (16+) cells
what occurs in morula
- outer cells begin to compact more than the ones in center
- form 2 different groups of cells
what are the 2 different groups of cells in the morula
inner
outer
morula–>
blastocyst (blastocoele formation)
prevent passage
tight junction
allow communication
gap junction
in morula, what occurs to form the blastocyst
- Na+ pumped into intercellular spaces
- water follows
what occurs in and early blastocyst
- fluid accumulates
- flattens outer cells
outer cells are called
trophoblast
inner cells are called
inner cell mass (ICM)
how does a hatched blastocyst form
- more fluid accumulates
- trophoblast cells produce enzymes
- enzymes breakdown ZP
- ZP weakens and breaks
- blastocyst oozes out
