explain the bryophyte plant life cycle with the help of a diagram
Life cycle of Bryophytes:
A clear alternation of generation is present in all bryophytes. They are the first plant to have heteromorphic alternation of generation. All bryophytes exhibit haplo- diplontic life cycle of heteromorphic type i.e. the plants represents two morphologically distinct generations ( gametophytic and sporophytic) with dominant independent gametophytic phase. Sporophyte is dependent on gametophyte for food. Hence, it remains attached to the gametophyte.
The haploid generation is called the gametophyte because it undergoes sexual reproduction to produce gametes. Production of gametes involve mitosis, so the gametes are also haploid. The gametes fuse to form a diploid zygote which grows into the next generation, the diploid sporophyte generation (2n). Sporophyte is dependent on gametophyte and remains attached to it. It is called sporophyte because it undergoes asexual reproduction to produce spores. Production of spores involves meiosis, so that there is return to the haploid condition. The haploid spores give rise to the gametophytic generation.
Little more information :
In Bryophytes, haploid gametophyte is independent, and photosynthetic. The bryophytes remain as gametophte for most of the life cycle. It alternates with multicellular sporophyte. The sporophytic is short lived that is totally or partially dependent on gametophyte for nutrition and anchorage. So, dominant phase in the life cycle of bryophytes is gametophytic phase.
Further more, Sporophyte is the phase in life cycle of plants which is diploid (means cells contain two sets of chromosomes). Sporophyte produces haploid spore through meiosis. Spores germinate into haploid plants also called haploid gametophytes. Gametophytes produces gametes.
Bryophytes show haplodiplontic cycle which is an intermediate condition of haplontic and diplontic life cycles. Both gametophytic (haploid) and sporophytic phases(diploid) are multicellular and often free-living.
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