This is a regulation of the internal environment of an organism.

homeostasis

Explanation:

The regulation of the internal environment of an organism is homeostasis. cells and organisms have an internal environment; cells regulate this environment so that it stays fairly constant.

both male and female gametes are produced by meiosis of the germ cells. therefore, both male and female gametes are haploid. one male and one female gamete unite during the fertilization to form the diploid zygote. in seed bearing plants, pollen grain is the male gametophyte, which produces sperm cells.