A gonad or sex gland or reproductive gland is an endocrine gland that produces the gametes (germ cells) o an organism. In the female o the species the reproductive cells are the egg cells, an in the male the reproductive cells are the sperm. The male gonad, the testicle, produces sperm in the form o spermatozoa. The female gonad, the ovary, produces egg cells. Baith o these gametes, are haploid germ cells.