Life cycle of an
angiosperm (flowering plant).
A plant alternates between a multicellular diploid (2n) sporophyte and
a multicellular haploid (n) gametophyte generation.
A mature plant is a multicellular diploid sporophyte with
reproductive structures.
Anthers contain microsporangia in which germ cells divide by
meiosis to produce microspores.
Ovaries contain megasporangia in which germ cells divide by
meiosis to yield 4 megaspores each.
Microspores divide by mitosis to form multicellular male
gametophytes (pollen grains), which contain sperm cells.
One of the 4 megaspores divides by mitosis to form a multicellular
female gametophyte (embryo sac), which contains an egg cell in an
ovule.
Fertilization (pollination) occurs when a sperm fuses with an egg,
producing a diploid single-celled zygote.
The zygote develops by mitosis to produce the sporophyte.