Matches in DBpedia 2016-04 for { <http://dbpedia.org/resource/Alternation_of_generations> ?p ?o }
- Alternation_of_generations abstract "Alternation of generations (also known as metagenesis) is a term primarily used to describe the life cycle of plants (taken here to mean the Archaeplastida). A multicellular gametophyte, which is haploid with n chromosomes, alternates with a multicellular sporophyte, which is diploid with 2n chromosomes, made up of n pairs. A mature sporophyte produces spores by meiosis, a process which reduces the number of chromosomes to half, from 2n to n. Because meiosis is a key step in the alternation of generations, it is likely that meiosis has a fundamental adaptive function. The nature of this function is still unresolved (see Meiosis), but the two main ideas are that meiosis is adaptive because it facilitates repair of DNA damage and/or that it generates genetic variation.The haploid spores germinate and grow into a haploid gametophyte. At maturity, the gametophyte produces gametes by mitosis, which does not alter the number of chromosomes. Two gametes (originating from different organisms of the same species or from the same organism) fuse to produce a zygote, which develops into a diploid sporophyte. This cycle, from gametophyte to gametophyte (or equally from sporophyte to sporophyte), is the way in which all land plants and many algae undergo sexual reproduction.The relationship between the sporophyte and gametophyte varies among different groups of plants. In those algae which have alternation of generations, the sporophyte and gametophyte are separate independent organisms, which may or may not have a similar appearance. In liverworts, mosses and hornworts, the sporophyte is less well developed than the gametophyte and is largely dependent on it. Although moss and hornwort sporophytes can photosynthesise, they require additional photosynthate from the gametophyte to sustain growth and spore development and depend on it for supply of water, mineral nutrients and nitrogen. By contrast, in all modern vascular plants the gametophyte is less well developed than the sporophyte, although their Devonian ancestors had gametophytes and sporophytes of approximately equivalent complexity. In ferns the gametophyte is a small flattened autotrophic prothallus on which the young sporophyte is briefly dependent for its nutrition. In flowering plants, the reduction of the gametophyte is much more extreme; it consists of just a few cells which grow entirely inside the sporophyte.All animals develop differently. A mature animal is diploid and so is, in one sense, equivalent to a sporophyte. However, an animal directly produces haploid gametes by meiosis. No haploid spores capable of dividing are produced, so neither is a haploid gametophyte. There is no alternation between diploid and haploid forms.Other organisms, such as fungi, can have life cycles in which different kinds of organism alternate. The term 'alternation of generations' has also been applied to these cases.Life cycles of plants and algae with alternating haploid and diploid multicellular stages are referred to as diplohaplontic (the equivalent terms haplodiplontic, diplobiontic or dibiontic are also in use). Life cycles, such as those of animals, in which there is only a diploid multicellular stage are referred to as diplontic. (Life cycles in which there is only a haploid multicellular stage are referred to as haplontic.)".
- Alternation_of_generations thumbnail Alternation_of_generations_simpler.svg?width=300.
- Alternation_of_generations wikiPageExternalLink paleo_1994_BatemanDiMichele_Heterospory_BiolRev_small.pdf.
- Alternation_of_generations wikiPageExternalLink default.htm.
- Alternation_of_generations wikiPageID "66535".
- Alternation_of_generations wikiPageLength "38567".
- Alternation_of_generations wikiPageOutDegree "114".
- Alternation_of_generations wikiPageRevisionID "704247495".
- Alternation_of_generations wikiPageWikiLink Adelbert_von_Chamisso.
- Alternation_of_generations wikiPageWikiLink Algae.
- Alternation_of_generations wikiPageWikiLink AlgaeBase.
- Alternation_of_generations wikiPageWikiLink Archaeplastida.
- Alternation_of_generations wikiPageWikiLink Autotroph.
- Alternation_of_generations wikiPageWikiLink Biological_life_cycle.
- Alternation_of_generations wikiPageWikiLink Bryophyte.
- Alternation_of_generations wikiPageWikiLink Category:Plant_reproduction.
- Alternation_of_generations wikiPageWikiLink Category:Reproduction.
- Alternation_of_generations wikiPageWikiLink Ceratopteris.
- Alternation_of_generations wikiPageWikiLink Chromalveolata.
- Alternation_of_generations wikiPageWikiLink Chromosome.
- Alternation_of_generations wikiPageWikiLink Cladophora.
- Alternation_of_generations wikiPageWikiLink Cnidaria.
- Alternation_of_generations wikiPageWikiLink Complementation_(genetics).
- Alternation_of_generations wikiPageWikiLink Double_fertilization.
- Alternation_of_generations wikiPageWikiLink Eduard_Strasburger.
- Alternation_of_generations wikiPageWikiLink Embryophyte.
- Alternation_of_generations wikiPageWikiLink Endosperm.
- Alternation_of_generations wikiPageWikiLink Entomophily.
- Alternation_of_generations wikiPageWikiLink Equisetum.
- Alternation_of_generations wikiPageWikiLink Evolutionary_history_of_plants.
- Alternation_of_generations wikiPageWikiLink Fern.
- Alternation_of_generations wikiPageWikiLink Fertilisation.
- Alternation_of_generations wikiPageWikiLink Flowering_plant.
- Alternation_of_generations wikiPageWikiLink Foraminifera.
- Alternation_of_generations wikiPageWikiLink Gamete.
- Alternation_of_generations wikiPageWikiLink Gametophyte.
- Alternation_of_generations wikiPageWikiLink Gene_product.
- Alternation_of_generations wikiPageWikiLink Genome_size.
- Alternation_of_generations wikiPageWikiLink Glaucophyte.
- Alternation_of_generations wikiPageWikiLink Green_algae.
- Alternation_of_generations wikiPageWikiLink Gymnosperm.
- Alternation_of_generations wikiPageWikiLink Heterogamy.
- Alternation_of_generations wikiPageWikiLink Heterokaryon.
- Alternation_of_generations wikiPageWikiLink Hornwort.
- Alternation_of_generations wikiPageWikiLink Ilex_aquifolium.
- Alternation_of_generations wikiPageWikiLink Japetus_Steenstrup.
- Alternation_of_generations wikiPageWikiLink Karyogamy.
- Alternation_of_generations wikiPageWikiLink Ladislav_Josef_Čelakovský.
- Alternation_of_generations wikiPageWikiLink Lycopodiopsida.
- Alternation_of_generations wikiPageWikiLink Marchantiophyta.
- Alternation_of_generations wikiPageWikiLink Meiosis.
- Alternation_of_generations wikiPageWikiLink Mitosis.
- Alternation_of_generations wikiPageWikiLink Monoicous.
- Alternation_of_generations wikiPageWikiLink Moss.
- Alternation_of_generations wikiPageWikiLink Multinucleate.
- Alternation_of_generations wikiPageWikiLink Mutation.
- Alternation_of_generations wikiPageWikiLink Mycelium.
- Alternation_of_generations wikiPageWikiLink Nathanael_Pringsheim.
- Alternation_of_generations wikiPageWikiLink Parthenogenesis.
- Alternation_of_generations wikiPageWikiLink Plant.
- Alternation_of_generations wikiPageWikiLink Plasmogamy.
- Alternation_of_generations wikiPageWikiLink Ploidy.
- Alternation_of_generations wikiPageWikiLink Prothallium.
- Alternation_of_generations wikiPageWikiLink Red_algae.
- Alternation_of_generations wikiPageWikiLink Sea_lettuce.
- Alternation_of_generations wikiPageWikiLink Seed.
- Alternation_of_generations wikiPageWikiLink Sexual_reproduction.
- Alternation_of_generations wikiPageWikiLink Slime_mold.
- Alternation_of_generations wikiPageWikiLink Sorus.
- Alternation_of_generations wikiPageWikiLink Species.
- Alternation_of_generations wikiPageWikiLink Spermatophyte.
- Alternation_of_generations wikiPageWikiLink Splachnum_sphaericum.
- Alternation_of_generations wikiPageWikiLink Sporangium.
- Alternation_of_generations wikiPageWikiLink Spore.
- Alternation_of_generations wikiPageWikiLink Sporophyte.
- Alternation_of_generations wikiPageWikiLink Trematoda.
- Alternation_of_generations wikiPageWikiLink Tunicate.
- Alternation_of_generations wikiPageWikiLink Ulva_lactuca.
- Alternation_of_generations wikiPageWikiLink Vascular_plant.
- Alternation_of_generations wikiPageWikiLink Wilhelm_Hofmeister.
- Alternation_of_generations wikiPageWikiLink Willow.
- Alternation_of_generations wikiPageWikiLink Zygote.
- Alternation_of_generations wikiPageWikiLink File:Alternation_of_generations_complex.svg.
- Alternation_of_generations wikiPageWikiLink File:Alternation_of_generations_simpler.svg.
- Alternation_of_generations wikiPageWikiLink File:Blechnum_discolor_-_crown_fern.jpg.
- Alternation_of_generations wikiPageWikiLink File:Hollyflowers.jpg.
- Alternation_of_generations wikiPageWikiLink File:Mnium_hornum_2005.04.02_14.55.41.jpg.
- Alternation_of_generations wikiPageWikiLink File:Onoclea_sensibilis_4_crop.jpg.
- Alternation_of_generations wikiPageWikiLink File:Pellia_epiphylla_IMG_1610.jpg.
- Alternation_of_generations wikiPageWikiLinkText "Alternation of generations".
- Alternation_of_generations wikiPageWikiLinkText "alternating generation".
- Alternation_of_generations wikiPageWikiLinkText "alternating multicellular generations".
- Alternation_of_generations wikiPageWikiLinkText "alternating".
- Alternation_of_generations wikiPageWikiLinkText "alternation of diploid and haploid generations".
- Alternation_of_generations wikiPageWikiLinkText "alternation of generations".
- Alternation_of_generations wikiPageWikiLinkText "alternation".
- Alternation_of_generations wikiPageWikiLinkText "diplohaplontic".
- Alternation_of_generations wikiPageWikiLinkText "during their developmental history".
- Alternation_of_generations wikiPageWikiLinkText "generation phase".
- Alternation_of_generations wikiPageWikiLinkText "generation".