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Blastocyst Embryonic Development - Anatomy & Physiology (view source)
Revision as of 16:35, 4 September 2008
, 16:35, 4 September 2008→Pre-Implantation Development
* In the Ootid, male and female '''pronuclei''' along with the first and second '''polar bodies''' are present.
* In the Ootid, male and female '''pronuclei''' along with the first and second '''polar bodies''' are present.
* Fusion of the male and female pronuclei results in a single '''diploid nucleus''' ('''Syngamy''')
* Fusion of the male and female pronuclei results in a single '''diploid nucleus''' ('''Syngamy''')
* This causes the '''zona pellucida''' to form around the zygote. This is an imprenetrable layer that prevents polyspermy and so polyploidy.
* The '''zona pellucida''' the becomes an imprenetrable layer that prevents polyspermy and so polyploidy.
* '''Zygote''' (diploid) undergoes mitotic divisions ('''cleavage''').
* '''Zygote''' (diploid) undergoes mitotic divisions ('''cleavage''').
* Cleavage gives rise to daughter cells called '''Blastomeres'''.
* Cleavage gives rise to daughter cells called '''Blastomeres'''.