请输入您要查询的英文单词:

 

单词 gametophyte
释义

gametophyte

enUK

ga·me·to·phyte

G0031100 (gə-mē′tə-fīt′)n. Botany The haploid gamete-producing phase in a plant characterized by alternation of generations.
ga·me′to·phyt′ic (-fĭt′ĭk) adj.

gametophyte

(ɡəˈmiːtəʊˌfaɪt) n (Botany) the plant body, in species showing alternation of generations, that produces the gametes. Compare sporophyte gametophytic adj

ga•me•to•phyte

(gəˈmi təˌfaɪt, ˈgæm ɪ-)

n. the sexual form of a plant in the alternation of generations. Compare sporophyte. [1890–95]

ga·me·to·phyte

(gə-mē′tə-fīt′) In plants, fungi, and certain algae, the individual organism or generation of organisms that produces reproductive cells (called gametes). Each cell of a gametophyte has only one set of chromosomes, just as its gametes do. In nonvascular plants, such as the mosses and liverworts, the gametophyte is the main plant form. In vascular plants, such as the ferns, grasses, conifers, and flowering plants, the gametophyte consists of only a few cells—the embryo sac and the pollen grain. Compare sporophyte.
Thesaurus
Noun1.gametophyte - the gamete-bearing individual or phase in the life cycle of a plant having alternation of generationsgametophyte - the gamete-bearing individual or phase in the life cycle of a plant having alternation of generationsplant life, flora, plant - (botany) a living organism lacking the power of locomotionmegagametophyte - the female gametophyte produced by the megaspore of a plant that produces both microspore and megasporesmicrogametophyte - the male gametophyte produced by a microspore

gametophyte

enUK

gametophyte

(gəmē`təfīt'), phase of plant life cycles in which the gametes, i.e., egg and sperm, are produced. The gametophyte is haploid, that is, each cell contains a single complete set of chromosomes, and arises from the germination of a haploid spore. In many lower plants, the gametophyte phase is the dominant plant form; for example, the familiar mosses are the gametophyte form of the plants. The alternate phase of the plant life cycle is the sporophyte, the diploid plant form, with each cell containing two complete sets of chromosomes. For example, in mosses the sporophyte is a capsule atop a slender stalk that grows out of the top of the gametophyte. The sporophyte develops from the union of two gametes, such as an egg fertilized by a sperm; in turn, the sporophyte forms spores that develop into gametophytes. The alternation between haploid gametophyte and diploid sporophyte phases, known as alternation of generations, occurs in all multicellular plants. As plants advanced in evolutionary development, the sporophyte became the increasingly dominant plant form and the gametophyte form has been correspondingly reduced. In contrast to mosses, for example, in the advanced angiosperms the male and female gametophytes are reduced to three-celled and seven-celled structures, respectively, found within the reproductive organs of the familiar flowering plant (the sporophyte). See also fertilizationfertilization,
in biology, process in the reproduction of both plants and animals, involving the union of two unlike sex cells (gametes), the sperm and the ovum, followed by the joining of their nuclei.
..... Click the link for more information.
; reproductionreproduction,
capacity of all living systems to give rise to new systems similar to themselves. The term reproduction may refer to this power of self-duplication of a single cell or a multicellular animal or plant organism.
..... Click the link for more information.
.

Gametophyte

 

sexual generation in those plants that exhibit alternation of generations. The gametophyte alternates in the development cycle with the asexual generation or sporophyte. In many plants the gametophyte carries on an autonomous existence, independent of the sporophyte. In some cases it is not distinguishable from the sporophyte by its external appearance (for example, the gametophyte in many algae); in others it is very distinct, for example, in the prothallia of ferns, horsetails, and lycopodia. In angiospermous plants the gametophyte is reduced to a pollen grain (male gametophyte) and to an embryo sac (female gametophyte). The gametophyte cell nuclei are characterized by half the number (haploid) of chromosomes in comparison to the cell nuclei of the sporophyte.

gametophyte

[gə′mēd·ə‚fīt] (botany) The haploid generation producing gametes in plants exhibiting metagenesis. An individual plant of this generation.
随便看

 

英语词典包含2567994条英英释义在线翻译词条,基本涵盖了全部常用单词的英英翻译及用法,是英语学习的有利工具。

 

Copyright © 2004-2022 Newdu.com All Rights Reserved
更新时间:2025/3/20 3:36:21