| A | B |
|---|
| amnion | the membrane that lies just inside the chorion. It encloses the amniotic fluid |
| amniotic fluid | cushions the embryo against shock. Together with the chorin keeps the embryo from drying out |
| blastula | the hollow-ball stage of the developing embryo made up of a single layer of cells |
| chorion | a membrane that lies directly under the shell and completely encloses the embryo and the other membranes |
| egg | a female gamete |
| embryo | a multicellular organism in the early stages of development |
| embryology | the study of development of an organism from fertilization until bith |
| fertilization | the union (joining) of the egg and sperm nuclei to form a zygote |
| gametes | mature sex cells |
| gametogenesis | the development of the mature sex cells |
| gastrula | formed when one side of the blastula pushes inward resulting in the formation of a second, inner layer of cells |
| gonads | the reproductive organs of the animal |
| hermaphrodites | both the male and female gonads are located on the same animal |
| morula | a solid- ball of the cellswhich develops from the zygote through cell division |
| oogenesis | this process by which the eggs develop in the ovaries of the female |
| ova | the egg or female gamete |
| oviducts | where fertilization tkaes place in female mammals |
| placenta | in ammmals, a temporary organ through which the embryo receives food and oxygen from the mather's body and gets rid of wastes |
| sexual reproduction | is a type of reproduction that involves two parents |
| spermatogenesis | the process by which sperm develops in the testes of the male |
| testes | male sex organism |
| umbilical cord | the sturcture that connects the embryo to the placenta |
| uterus | specialized organ where the mammal embryo develops |
| zygote | the fertilized egg |
| ovaries | the female gonads |
| sperm | the male gamete |
