The life cycle of an angiosperm starts out when the sporophyte creates microspores that form megaspores and gametophytes (Female and Male reproductive respectively). The male cell is made of two haploid cells, one becoming sperm(pollen) and the other becoming a pollen tube. The females gametophyte(embryo sac) contains the egg cell. After the pollen falls down the style of the plant it fertilizes the egg forming a zygote which is then covered in a protective layer containing nutrition (seed). A seed then only has to germinate and mature for the process to repeat itself.