Ecosystems are different from another by its kinds and amounts of?

Populations of different species linking with each other in a region.

Explanation:

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.