| A | B |
|---|
| the joining of an egg and sperm can only occur if... | an egg is present in the fallopian tube |
| when must intercource occur for fertilization to be possible? | w/in 3 days of ovulation |
| zygote | the new cell formed as a result of fertilization |
| morula | the solid ball of cells formed in early development |
| blastocyst | the hollow ball of cells formed in early development |
| implantation | the process in which the embryo attaches to the wall of the uterus |
| embryo | the lump of cell sin the blastocyst will later become this |
| if implantation does not occur..... | pregnancy does not occur |
| ectoderm | outer germ layer |
| mesoderm | middle germ layer |
| endoderm | inner germ layer |
| herm layers | three layers of cells, formed w/ing the blasocyst |
| outer layer of blastocyst develops into how many tissues what are they called? | 2: inner - amnion, outer - chorion |
| placenta | an organ through which materials are exhanged between the mother and the developing embryo |
| placenta is filled with | blood vessels |
| fetus | from the ninth week until birth, the developing human |
| what starts the birth process? | a surge of the pituitary hormone oxytin |
