Variation in plant life cycle
key concept
All plants have a life cycle that alternates between diploid sporophyte and haploid gametophyte generations between sexual and asexual reproduction in nonvascular plants , gametophyte generation is dominant in vascular plants , the sporophyte generation is dominant. Seedless vascular plants ,such as ferns , reproduce with spores. Seed plants reproduce with pollen and eggs in cones or flower. Pollination must occur for fertilization to take place and seeds to develop.