Pre-implantation

Pre-Implantation   Fertilization...  --Begins with the union of sperm and egg --Only one sperm can fertilize an egg  During Fertilization...  --Sperm releases enzymes that pierce through the egg's coating --Sperm’s surface proteins bind to the egg's receptor protein --Sperm and egg plasma membranes fuse and nuclei unite --Changes in the egg membrane prevents entry of additional sperm --Fertilization egg called (zygote) --Develops into embryo  

Embryonic Development  1) **__Zygote __**Sperm fertilizes eggs Cleavage-rapid series of cell division- first few mitotic cell division 2) **__Morula __**<span style="font-size: 13pt; line-height: 150%; font-family: 'Arial','sans-serif'; mso-fareast-font-family: 'Times New Roman';"> <span style="font-size: 13pt; line-height: 150%; font-family: 'Arial','sans-serif'; mso-fareast-font-family: 'Times New Roman';">Consists of a solid ball of cells <span style="font-size: 13pt; line-height: 150%; font-family: 'Arial','sans-serif'; mso-fareast-font-family: 'Times New Roman';">Embryonic stem cells phase <span style="font-size: 13pt; line-height: 150%; font-family: 'Arial','sans-serif'; mso-fareast-font-family: 'Times New Roman';">3) **__<span style="font-size: 12pt; line-height: 150%; font-family: 'Arial','sans-serif'; mso-fareast-font-family: 'Times New Roman';">Blastula __**<span style="font-size: 13pt; line-height: 150%; font-family: 'Arial','sans-serif'; mso-fareast-font-family: 'Times New Roman';"> <span style="font-size: 13pt; line-height: 150%; font-family: 'Arial','sans-serif'; mso-fareast-font-family: 'Times New Roman';">During each mitotic division the embryo does not increase is size the existing cytoplasm divides <span style="font-size: 13pt; line-height: 150%; font-family: 'Arial','sans-serif'; mso-fareast-font-family: 'Times New Roman';"> <span style="font-size: 13pt; line-height: 115%; font-family: 'Arial','sans-serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">__Implantation__ <span style="font-size: 13pt; line-height: 150%; font-family: 'Arial','sans-serif'; mso-fareast-font-family: 'Times New Roman';">--When blastocyst attaches to the uterine wall <span style="font-size: 13pt; line-height: 150%; font-family: 'Arial','sans-serif'; mso-fareast-font-family: 'Times New Roman';">4) **__<span style="font-size: 12pt; line-height: 150%; font-family: 'Arial','sans-serif'; mso-fareast-font-family: 'Times New Roman';"> Gastrula __**<span style="font-size: 13pt; line-height: 150%; font-family: 'Arial','sans-serif'; mso-fareast-font-family: 'Times New Roman';"> <span style="font-size: 13pt; line-height: 150%; font-family: 'Arial','sans-serif'; mso-fareast-font-family: 'Times New Roman';">Formation of the 3 germ layers <span style="font-size: 13pt; line-height: 150%; font-family: 'Arial','sans-serif'; mso-fareast-font-family: 'Times New Roman';">-__Endoderm__-inner most layer-becomes organs <span style="font-size: 13pt; line-height: 150%; font-family: 'Arial','sans-serif'; mso-fareast-font-family: 'Times New Roman';">-__Mesoderm__-middle layer-becomes muscles <span style="font-size: 13pt; line-height: 150%; font-family: 'Arial','sans-serif'; mso-fareast-font-family: 'Times New Roman';">-__Ectoderm__-outer most layer-becomes skin