What is the difference between an extinction and a mass extinction?

mass extinction is usually defined as a loss of about three quarters of all species in existence across the entire Earth over a short geological period of time.

Extinction are defined as species that go extinct simply because not all life can be sustained on Earth and some species simply cannot survive.

is this a psat question, if so do not cheat try your best.

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.