fertilization and zygote formation Flashcards
1
Q
what does sperm fusion with egg trigger?
A
completion of meiosis II, which results in one egg and 3 polar bodies
2
Q
how does zygote become diploid?
A
haploid germ cell pronuclei fuse inside the egg
3
Q
fast block?
A
block to polyspermy. calcium2+ wave blocks membrane. electrical properties of membrane prevent further fusion with egg.
4
Q
slow block?
A
after granules release contents due to fast black, zone reaction happens. enzymes from granules lead to the zona reaction.
5
Q
zona reaction
A
polymerization of ZP glycoproteins to prevent further sperm access to egg.
6
Q
when is ZP lost?
A
at blastocyst
7
Q
when do pronuclei fuse in egg?
A
about 4 to 5 hours after activation of the egg
8
Q
zygote
A
one cell embryo
