| 翻訳と辞書 |
monoicous
Monoicous plants are those species that bear both sperm and eggs on the same gametophyte. Dioicous plants are those that have gametophytes that produce only sperm or eggs but never both.〔Crandall-Stotler, B.J. & Bartholomew-Began, S.E. (2007). ''Morphology of Mosses (Phylum Bryophyta)''. In: Flora of North America Editorial Committee, eds. (1993+). ''Flora of North America North of Mexico''. 16+ vols. New York and Oxford. Volume 27, 2007.〕〔Bell, P.R. & Helmsley, A.R. (2000). ''Green plants, their origin and diversity'' (2nd ed.). Cambridge University Press.〕 The terms are used largely but not exclusively in the context of bryophytes. Both monoicous and dioicous gametophytes produce gametes in gametangia by mitosis rather than meiosis, so that sperm and eggs are genetically identical with their parent gametophyte. The states of being monoicous or dioicous are called monoicy and dioicy respectively.
==Etymology and history==
The word monoicous and the related forms mon(o)ecious are derived from the Greek mόνος (''mónos''), ''single'', and οἶκος (''oîkos'') or οἰκία (''oikía''), ''house''. The words dioicous and di(o)ecious are derived from οἶκος or οἰκία and δι- (di-), twice, double. (''(o)e'' is the Latin way of transliterating Greek οι, whereas ''oi'' is a more straightforward modern way.) Generally, the terms "monoicous" and "dioicous" have been restricted to description of haploid sexuality (gametophytic sexuality), and are thus used primarily to describe bryophytes in which the gametophyte is the dominant generation. Meanwhile, "monoecious" and "dioecious" are used to describe diploid sexuality (sporophytic sexuality), and thus are used to describe tracheophytes (vascular plants) in which the sporophyte is the dominant generation.〔Shaw, A. Jonathan & Goffinet, Bernard eds. (2000). ''Bryophyte Biology''. New York: Cambridge University Press.〕 However, this usage, although precise, is not universal, and "monoecious" and "dioecious" are still used by some bryologists for the gametophyte.〔See e.g. .〕
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』
■ウィキペディアで「monoicous」の詳細全文を読む
スポンサード リンク
| 翻訳と辞書 : 翻訳のためのインターネットリソース |
Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.
|
|