When and where does reduction division take place in the life cycle of a liverwort, a moss, a fern, a gymnosperm and an angiosperm?

Liverwort – In liverworts, the main plant-body is haploid (gametophytic). It bears the male and female sex organs which produce gametes. These gametes fuse to form a zygote. The zygote develops on the gametophytic plant-body to form a sporophyte. The sporophyte is differentiated into the foot, seta, and capsule. Many haploid spores are produced as a result of the reduction division taking place inside the capsule.
Moss – In mosses, the primary protonema (developed in the first stage) develops into the secondary protonema. Both these stages are haploid or gametophytic. The secondary protonema bears the sex organs which produce gametes. These gametes fuse to form a zygote. The zygote develops into a sporophyte. Many spores are formed as a result of the reduction division taking place in the capsule of this sporophyte.
Fern – In ferns, the main plant-body is sporophytic. Its leaves are known as sporophylls and these bear the sporangia. Reduction division takes place in these sporangia, thereby producing many spores.
Gymnosperm – In gymnosperms, the main plant-body is sporophytic. They bear two types of leaves – microsporophylls and megasporophylls. Reduction division takes place in the microsporangia present on the microsporophylls (producing pollen grains) and on the megasporangia present on the megasporophylls (producing megaspores).
Angiosperm – In angiosperms, the main plant-body is sporophytic and bears flowers. The male sex organ in the flower is the stamen, while the female sex organ is the pistil. Reduction division takes place in the anthers of the stamen (producing haploid pollen grains) and in the ovary of the pistil (producing eggs).

In case of liverwort, moss and fern; the saprophytic plant produces haploid spores after meiosis. In case of gymnosperm and angiosperm, meiosis takes place in antheridium and ovary; for the formation of pollen grains and ovules. 

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.