alternation of generations
- alternation of generations
al·ter·na·tion of generations .ȯl-tər-'nā-shənalso .al- n the occurrence of two or more forms differently produced in the life cycle of a plant or animal usu. involving the regular alternation of a sexual with an asexual generation but not infrequently consisting of alternation of a dioecious generation with one or more parthenogenetic generations
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the regular alternation of two or more different forms or of different modes of reproduction in the life cycle; it may be used specifically for the alternating formation of diploid and haploid generations.
Medical dictionary.
2011.
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Alternation of generations — (also known as alternation of phases or metagenesis) is a term primarily used in describing the life cycle of plants (taken here to mean the Archaeplastida). A multicellular sporophyte, which is diploid with 2N paired chromosomes (i.e. N pairs),… … Wikipedia
alternation of generations — n. the regular alternation of two distinct body forms in the life cycle of a plant or animal, usually an alternation between a form that reproduces sexually and one that reproduces asexually … English World dictionary
alternation of generations — Biol. the alternation in an organism s life cycle of dissimilar reproductive forms, esp. the alternation of sexual with asexual reproduction. [1855 60] * * * In biology, alternation of a sexual phase (gametophyte) and a nonsexual phase… … Universalium
alternation of generations — noun the alternation between generations of asexual with sexual reproduction in certain plants and animals, as in mosses and tapeworms …
alternation of generations — The alternation of two or more generations reproducing in different ways; an alternation of sexual and asexual, or parasitic with a free living cycle; see alloiogenesis, digenesis, heterogamy, heterogenesis,heterogonymetagenesis … Dictionary of invertebrate zoology
alternation of generations — alterna′tion of genera′tions n. dvl the alternation in an organism s life cycle of dissimilar reproductive forms, esp. the alternation of sexual with asexual generations • Etymology: 1855–60 … From formal English to slang
alternation of generations — Date: 1858 the occurrence of two or more forms differently produced in the life cycle of a plant or animal usually involving the regular alternation of a sexual with an asexual generation … New Collegiate Dictionary
alternation of generations — noun Biology a pattern of reproduction shown by some lower plants and invertebrates, involving a regular alternation between sexual and asexual forms (as in ferns) or dioecious and parthenogenetic forms (as in some jellyfishes) … English new terms dictionary
alternation of generations — noun the alternation of two or more different forms in the life cycle of a plant or animal • Syn: ↑heterogenesis, ↑xenogenesis • Hypernyms: ↑organic phenomenon • Hyponyms: ↑metagenesis, ↑digenesis … Useful english dictionary
alternation of life phases — , less correctly alternation of generations. Having distinct sporophytic (diploid), e.g. stems, roots, leaves, cones, etc., and gametophytic (haploid), e.g. tissue within the seeds of cycads and all other seed plants, phases in the life cycle … Expanded glossary of Cycad terms
