Gonads are organs that produce cells that join with other cells during the fertilization process. Gonads are present in both male and female genitalia. In males, they present as testicles. In females, they present as ovaries. The cells they house are called gametes. In males, the gametes are sperm. In females, the gametes are egg cells.
More About Gonads
In utero during the earliest stage of fetal development, all gonads are the same. They do not develop into male or female sex organs until later in development depending on the presence of the SRY gene on the Y chromosome. If it is there, male sex and urniary organs develop. If it is not female ones do.