Adiscrete structure composed of at least two tissue types that performs a specific function
for the body is
tissue
cell
cell system
organ
organ system

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.