WEEK 1 - Fertilization Creates Babies Immediately = FCBI --> F-fertilization, C-cleavage, B-blastocyst, I-implantation.

•       F-fertilization:  Occur in the ampulla of the fallopian tube.  Sperm binds the ZP (zona pellucida) of the secondary oocyte -->acrosome reaction (enzymes breakdown ZP) --> sperm penetrate ZP --> cortical reaction (renders ZP impermeable to other sperm) --> sperm and secondary oocyte membrane fuse --> sperm male genetic material (MALE PRONUCLEUS) enters the secondary oocyte’s cytoplasm --> Male and female pronuclei fuse to form a zygote.

•       C-clevage:  Serial mitotic division of the zygote to form a blastocyst consisting of increasingly smaller blastomeres (the individual embryonic cells at this stage).   At the 32-cell stage, blastomeres form a morula.

•       Blastocyst formation (occur when fluid secreted within the morula):  The blastocyst consists of a spherical layer of around 128 cells surrounding a central fluid-filled cavity called the blastocoel.  It contains an ICM (inner cell mass) and an OCM (outer cell mass)

     o   ICM = Embryoblast --> embryo and fetus

     o   OCM = Trophoblast --> placenta.