1. Embryo Development

2. Fertilization During fertilization several events occur: The nuclei of the egg and sperm fuse. The zygote is formed. Polyspermy is blocked.

3. Cleavage Cellular division is mitotic not meiotic. Cleavage divisions form a small, solid ball of cells called a morula.

4. Blastulation Cleavage continues until a hollow ball, the blastula, is formed. The movement of the cells into an open interior creates room for germ layers to develop.

5. Gastrulation

6. Germ Layers Ectoderm Endoderm Archenteron Blastopore

8. Organogenesis

9. Cell Differentiation  Embyronic induction:  “The action of one group of cells on another leads to the establishment of the developmental pathway.”

10. Cell Differentiation  Homeotic genes:  “Genes that have control over a whole group of other genes and the time at which they are expressed.”

11. Cell Differentiation  MicroRNA’s:  The expression of various genes are regulated by microRNAs.

12. RNAi Technology Possible medical applications: Prevention of: Huntington’s disease HIV Hepatitis Measles

14. Protostomes vs Deuterostomes

16. Determination of cell fate: The type of tissue or organ a cell will become is determined: early in the developmental stage of a protostome. late in the developmental stage of a deuterostome.

17. Coelom Development

18. Embryonic Stem Cells Embryonic stem cells are different from other cells by their unique properties. They are: Totipotent Pluripotent Undifferentiated Uspecialized

19. Stem Cell Applications Current medical applications of stem cell research: Repair of brain and spinal tissues. Treatment of diseases Cloning Reprogramming of diseased cells. Testing of new drugs.