Reduction division occurs in gametic cells. The main aim is to halve the number of chromosomes for the purpose of fertilization.
Liverwort:
haplo-diplontic in nature, sporophyte generation is represented only by one-celled zygote. Reduction division results in information of haploid cells. Haploid spores mitotically divide to form gametophyte (main plant body). During sexual reproduction male and female sex, organs may be present or the same or different thalli.
A moss:
Reduction division in moss occurs similar to liverwort gametophyte which is a predominate stage hence haplodiplontic. It consists of 2 stages. First stage is the protonema stage, which develops directly from. a spore. Second stage is leafy stage which develops from secondary protonema as a lateral bud. This stage bears sex organs.
A fern:
fern is diplontic in nature. A dominant sporophyte body is present. Sporophytes bear sporophylls. Sporophylls (sporangia) produce spores by meiosis in spore mother cells. The spore geminate to give rise to inconspicuous small but multicellular free-living, mostly photosynthetic thalloid gametophytes called prothallus.
A Gymnosperm:
diplontic in nature. Gymnosperms are heterosporous as they produce haploid microspores and megaspores. The two kinds of spores are produced within sporangia that are borne on sporophylls which are arranged spirally along an axis to form lax or compact strobili or cones. The microspores develop into a male gametophytic generation which is highly reduced and is confined to only a limited number of cells. Megaspores develop into a female gametophyte generation.
An Angiosperm:
Diplontic in nature, male sex organs in a flower is the stamen. Each stamen consists of a slender filament with an anther at the tip. The anthers, following meiosis, produces pollen grains. The female sex organ in a flower is the pistil or carpel. Pistil consists of an ovary enclosing one or many ovules. Within ovules are present highly reduced female gametophytes termed embryosacs.
