The typical life cycle of terrestrial plants
and some seaweeds, in which there are two
distinct forms occurring alternately: diploid
(having two sets of chromosomes) and haploid
(one set of chromosomes). The diploid
generation produces haploid spores by
meiosis, and is called the sporophyte, while
the haploid generation produces gametes (sex
cells), and is called the gametophyte. The
gametes fuse to form a diploid zygote which
develops into a new sporophyte; thus the
sporophyte and gametophyte alternate.