When do the sun’s rays strike latitude 23.5°s at an angle of 90 degrees? september 21 december 21 march 21 june 21

December 21 (GradPoint Answer)

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.