Question

EXPLAIN HAPLONTIC, DIPONTIC AND HAPLO DIPLONTIC LIFE CYCLE

Answer 1

There are three patterns of life cycle –Haplontic, Diplontic & Haplo-diplontic.

• In haplontic life cycle, the dominant and photosynthetic phase is the free-living gametophyte. The sporophytic generation (diploid stage) is represented only by the one-celled zygote. There are no free-living sporophytes. In Haplontic life cycle, the zygote undergoes meiosis.

• In diplontic life cycle, diploid sporophyte is the dominant, photosynthetic, independent phase of the plant. The gametophytic phase is represented by the single celled (gametes) to few-celled haploid gametophyte. In Diplontic lifecycle, the zygote undergoes mitosis. (An organism having somatic cells with the diploid number of chromosomes).

• Haplodiplontic life cycle is an intermediate condition between haplontic and diplontic life cycle.Both gametophyte and sporophyte are free-living and multicellular, but have different dominant phases.