| A | B |
| egg | female sex cell |
| sperm | male sex cell |
| embryo | developing human during first 8 weeks after fertilization |
| estrogen | female hormone produced by the ovaries |
| fetus | developing huuman after the first |
| fertilization | the joining of a sperm and egg nuclei |
| ovulation | the process in which a mature egg is released from the ovary |
| ovary | female reproductive organ that produces eggs and estrogen |
| fallopian tube | female structure that connects the ovary and uterus |
| reproduction | the process by which living things create new individuals of the same type |