Eggs and sperms can unite to make diploid cells {zygote}|.
Plant cells can make organs {sporangium}| {sporangia}, which produce haploid spores by meiosis.
Most plants have two-stage sexual reproduction {generation alternation} {alternation of generations}|. First is gametophyte stage and then sporophyte stage. Bacteria and blue-green algae do not have generation alternation.
In first stage {gametophyte stage}|, male sex organ makes haploid sperm, and female sex organ makes haploid eggs. Eggs and sperms unite to make zygotes. Zygotes divide to form diploid cells.
In second stage {sporophyte stage}|, plant cells make sporangia, which produce haploid spores by meiosis. Haploid spores undergo mitosis to make haploid sperm and eggs for gametophyte stage.
Monogamous plants can have both sexes in two different plants {diecious}|.
Heterogamous plants can have both sexes in same plant {monoecious}|.
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Date Modified: 2022.0225