| slovo | definícia |
pollen tube
(encz) | pollen tube,pylová láčka n: [bot.] Jirka Daněk |
pollen tube
(gcide) | Spermatophyta \Sper`ma*toph"y*ta\, n. pl. [NL.; spermato- + Gr.
? plant.] (Bot.)
A phylum embracing the highest plants, or those that produce
seeds; the seed plants, or flowering plants. They form the
most numerous group, including over 120,000 species. In
general, the group is characterized by the marked development
of the sporophyte, with great differentiation of its parts
(root, stem, leaves, flowers, etc.); by the extreme reduction
of the gametophyte; and by the development of seeds. All the
Spermatophyta are heterosporous; fertilization of the egg
cell is either through a
pollen tube emitted by the microspore or (in a few
gymnosperms) by spermatozoids.
Note: The phrase "flowering plants" is less distinctive than
"seed plants," since the conifers, grasses, sedges,
oaks, etc., do not produce flowers in the popular
sense. For this reason the terms Anthrophyta,
Phaenogamia, and Panerogamia have been superseded
as names of the phylum by Spermatophyta.
[Webster 1913 Suppl.] |
Pollen tube
(gcide) | Pollen \Pol"len\, n. [L. pollen fine flour, fine dust; cf. Gr.
?]
1. Fine bran or flour. [Obs.] --Bailey.
[1913 Webster]
2. (Bot.) The fecundating dustlike cells of the anthers of
flowers. See Flower, and Illust. of Filament.
[1913 Webster]
Pollen grain (Bot.), a particle or call of pollen.
Pollen mass, a pollinium. --Gray.
Pollen sac, a compartment of an anther containing pollen,
-- usually there are four in each anther.
Pollen tube, a slender tube which issues from the pollen
grain on its contact with the stigma, which it penetrates,
thus conveying, it is supposed, the fecundating matter of
the grain to the ovule.
[1913 Webster] |
pollen tube
(wn) | pollen tube
n 1: (botany) a slender tubular outgrowth from a pollen grain
when deposited on the stigma for a flower; it penetrates
the style and conveys the male gametes to the ovule |
| | podobné slovo | definícia |
Pollen tube
(gcide) | Spermatophyta \Sper`ma*toph"y*ta\, n. pl. [NL.; spermato- + Gr.
? plant.] (Bot.)
A phylum embracing the highest plants, or those that produce
seeds; the seed plants, or flowering plants. They form the
most numerous group, including over 120,000 species. In
general, the group is characterized by the marked development
of the sporophyte, with great differentiation of its parts
(root, stem, leaves, flowers, etc.); by the extreme reduction
of the gametophyte; and by the development of seeds. All the
Spermatophyta are heterosporous; fertilization of the egg
cell is either through a
pollen tube emitted by the microspore or (in a few
gymnosperms) by spermatozoids.
Note: The phrase "flowering plants" is less distinctive than
"seed plants," since the conifers, grasses, sedges,
oaks, etc., do not produce flowers in the popular
sense. For this reason the terms Anthrophyta,
Phaenogamia, and Panerogamia have been superseded
as names of the phylum by Spermatophyta.
[Webster 1913 Suppl.]Pollen \Pol"len\, n. [L. pollen fine flour, fine dust; cf. Gr.
?]
1. Fine bran or flour. [Obs.] --Bailey.
[1913 Webster]
2. (Bot.) The fecundating dustlike cells of the anthers of
flowers. See Flower, and Illust. of Filament.
[1913 Webster]
Pollen grain (Bot.), a particle or call of pollen.
Pollen mass, a pollinium. --Gray.
Pollen sac, a compartment of an anther containing pollen,
-- usually there are four in each anther.
Pollen tube, a slender tube which issues from the pollen
grain on its contact with the stigma, which it penetrates,
thus conveying, it is supposed, the fecundating matter of
the grain to the ovule.
[1913 Webster] |
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