| A | B |
|---|
| gland | an organ that produces or releases a chemical |
| duct | a small tube where glands release chemicals |
| target cell | a cell that recognizes a specific hormone |
| hormone | a chemical produced by an endocrine gland |
| negative feedback | a system that is turned off by the condition it produces |
| fertilization | the joining of an egg and sperm |
| egg | female sex cell |
| sperm | male sex cell |
| zygote | a fertilized egg |
| penis | the male sex organ |
| scrotum | a sack of skin that contains the testes |
| semen | a fluid containing sperm and nutrients |
| fallopian tube | a passageway that an egg travels from an ovary to the uterus |
| vagina | a muscular passageway of the female reproductive system |
| uterus | a hollow, organ where a fertilized egg will become attached and grow into a fetus |
| menstrual cycle | a monthly cycle of changes that occur in females |
| menstruation | blood and tissue from the uterus leave the body |
| ovulation | the release of an egg from an ovary |
| adolescence | the stage where children become adults |
| puberty | the period of physical sexual development that leads to the ability to reproduce |
| ovaries | female reproductive structures that produce eggs |
