Gonadal development refers to the process by which the gonads, or reproductive organs, form and mature in an organism. In humans, this process begins during embryonic development, where primordial germ cells migrate to the developing gonads, differentiating into either testes or ovaries based on genetic and hormonal signals. The development of gonads is influenced by various factors, including sex chromosomes and hormones. In males, the presence of the Y chromosome typically leads to the formation of testes, which produce testosterone. In females, the absence of the Y chromosome results in the development of ovaries, which produce estrogen and progesterone, essential for reproductive functions.