contributed to the disproof of the ideas of spontaneous generation in the 1840s and 1850s. Haplontic life cycle A zygotic meiosis is a meiosis of a zygote immediately after karyogamy, which is the fusion of two cell nuclei. This way, the organism ends its diploid phase and produces several haploid cells. These cells divide mitotically to form either larger, multicellular individuals, or more haploid cells. Two opposite types of gametes (e.g., male and female) from these individuals or cells fuse to become a zygote. In the whole cycle, zygotes are the only diploid cell; mitosis occurs only in the haploid phase. The individuals or cells as a result of mitosis are haplonts, hence this life cycle is also called haplontic life cycle. Haplonts are: In archaeplastidans: some green algae (e.g., Chlamydomonas, Zygnema, Chara) In stramenopiles: some golden algae In alveolates: many dinoflagellates, e.g., Ceratium, Gymnodinium, some apicomplexans (e.g., Plasmodium) In rhizarians: some euglyphids, ascetosporeans In excavates: some parabasalids In amoebozoans: Dictyostelium In opisthokonts: most fungi (some chytrids, zygomycetes, some ascomycetes, basidiomycetes) Diplontic life cycle In gametic meiosis, instead of immediately dividing meiotically to produce haploid cells, the zygote divides mitotically to produce a multicellular diploid individual or a group of more unicellular diploid cells. Cells from the diploid individuals then undergo meiosis to produce haploid cells or gametes. Haploid cells may divide again (by mitosis) to form more haploid cells, as in many yeasts, but the haploid phase is not the predominant life cycle phase. In most diplonts, mitosis occurs only in the diploid phase, i.e. gametes usually form quickly and fuse to produce diploid zygotes. In the whole cycle, gametes are usually the only haploid cells, and mitosis usually occurs only in the diploid phase. The diploid multicellular individual is a diplont, hence a gametic meiosis is also called a diplontic life cycle. Diplonts are: In archaeplastidans: some green algae (e.g., Cladophora glomerata, Acetabularia) In stramenopiles: some brown algae (the Fucales, however, their life cycle can also be interpreted as strongly heteromorphic-diplohaplontic, with a highly reduced gametophyte phase, as in the flowering plants), some xanthophytes (e.g., Vaucheria), most diatoms, some oomycetes (e.g., Saprolegnia, Plasmopara viticola), opalines, some "heliozoans" (e.g., Actinophrys, Actinosphaerium) In alveolates: ciliates In excavates: some parabasalids In opisthokonts: animals, some fungi (e.g., some ascomycetes) Haplodiplontic life cycle In sporic meiosis (also commonly known as intermediary meiosis), the zygote divides mitotically to produce a multicellular diploid sporophyte. The