(N/A) Haplontic life cycle: It is seen in Volvox,Spirogyra,and Chlamydomonas. In this cycle,the sporophytic generation is represented only by the one-celled zygote. There are no free-living sporophytes. Meiosis in the zygote results in haploid spores that divide mitotically to form the gametophyte.
$(b)$ Diplontic life cycle: It is seen in gymnosperms and angiosperms. The diploid sporophyte is the dominant,photosynthetic,and independent phase of the plant. The gametophytic phase is represented by the single to few-celled haploid gametophyte.
$(c)$ Haplo-diplontic life cycle: It is seen in bryophytes and pteridophytes. Both phases are multicellular and often free-living,though they differ in their dominant phase. In bryophytes,the dominant phase is the gametophyte,while in pteridophytes,the dominant phase is the sporophyte.