● In plants, both haploid and diploid cells can divide by `color{Green}"mitosis"`. This ability leads to the formation of different plant bodies - `color{Green}"haploid and diploid"`.

● Thus, during the life cycle of any sexually reproducing plant, there is an `color{Green}"alternation of generations"` between gamete producing haploid gametophyte and spore producing diploid sporophyte.

● The plant body or the dominant phase in the life cycle may be a gametophyte as in algae and bryophytes or a sporophyte as in pteridophytes, gymnosperms and angiosperms.

● The `color{Green}"haploid gametophyte"` produces gametes by mitosis; the fusion of gametes by fertilization results in the formation of a diploid zygote.

● Following fertilization, the zygote also divides by mitosis to produce a `color{Green}"diploid sporophytic plant body"`.

● Haploid spores are produced by this plant body in `color{Green}"spore mother cells"` by meiosis.

● These in turn, divide by mitosis and germinate to form a haploid gametophyte once again.

● Plants show three major life cycle patterns with different dominant phases.

`star` `color{brown}"Haplontic life cycle"`
`star` `color{brown}"Diplontic life cycle"`
`star` `color{brown}"Haplodiplontic life cycle"`

● `color{brown}"The Dominant Phase"`: Free-living haploid gametophyte.

● `color{brown}"Sporophytic Generation"`: Represented only by the one-celled zygote. There are no free-living sporophytes.

● `color{brown}"Gametophye Generation"`: Zygote undergoes meiosis to form haploid spores. The haploid spores divide mitotically and form the dominant, photosynthetic free living gametophyte.

● `color{brown}"E.g"` :Most of the algae like 𝘝𝘰𝘭𝘷𝘰𝘹, 𝘚𝘱𝘪𝘳𝘰𝘨𝘺𝘳𝘢 and some species of 𝘊𝘩𝘭𝘢𝘮𝘺𝘥𝘰𝘮𝘰𝘮𝘢𝘴

● `color{brown}"The Dominant phase"`: Independent diploid sporophyte.

● `color{brown}"Sporophytic Generation"`: Dominant, photosynthetic, independent phase of the plant.

● `color{brown}"Gametophye Generation"`: Represented by the single to few-celled haploid gametophyte

●`color{brown}"E.g"` : All seed-bearing plants i.e. gymnosperms and angiosperms

● `color{brown}"The Dominant phase"`: Either the diploid sporophyte or the haploid gametophyte.

● `color{brown}"Sporophytic Generation"`: Multicellular
● `color{brown}"Gametophye Generation"`: Multicellular

● `color{brown}"Bryophytes"`: The dominant and the indpendent phase is the thalloid gametophyte which alternates with the comparatively short-lived multicellular sporophyte, which is dependent on the gametophyte.

● `color{brown}"Pteridophytes"`: The dominant phase is represented by the independent sporophytic plant body which alternates with the short-lived, inconspicuous, multicellular, autotrophic and independent gametophyte.

● `color{brown}"E.g"` : Bryophytes, pteridophytes and some algae like 𝘌𝘤𝘵𝘰𝘤𝘢𝘳𝘱𝘶𝘴, 𝘗𝘰𝘭𝘷𝘴𝘪𝘱𝘩𝘰𝘯𝘪𝘢 and sea kelps.