from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Botany The gamete-producing phase in a plant characterized by alternation of generations.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A plant (or the haploid phase in its life cycle) which produces gametes by mitosis in order to produce a zygote.
from the GNU version of the Collaborative International Dictionary of English
- n. In the alternation of generations in plants, that generation or phase which bears sex organs and produces gametes. In the lower plants, as the algæ, the gametophyte is the conspicuous part of the plant body; in mosses it is the so-called moss plant; in ferns it is reduced to a small, early perishing body; and in seed plants it is usually microscopic or rudimentary.
from The Century Dictionary and Cyclopedia
- n. In thallophytes, the sexual form of the plant, as distinguished from the sporophyte, or asexual form.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. the gamete-bearing individual or phase in the life cycle of a plant having alternation of generations
Anthocerotales are a small and very distinct group, in which the gametophyte is a thallus, while the sporogonium possesses a sterile columella and is capable of long-continued growth and spore production.
The sexual form, called the gametophyte or prothallia, is a tiny kidney-shaped plant and difficult to find in the wild.
Ulva produces isomorphic thalli for its diploid sporophyte and haploid gametophyte.
Sometimes she could remember, sometimes there were flashes of brilliance, but sometimes she was lucky to remember the difference between the gametophyte and sporophyte stages of a fern.
The gametophyte or prothallial generation is thus extremely reduced, consisting of but little more than the male and female sexual cells -- the two sperm-cells in the pollen-tube and the egg-cell (with the synergidae) in the embryo-sac.
The last-mentioned case has been regarded as representing an apogamous development of the sporophyte from the gametophyte comparable to the cases of apogamy described in Ferns.
The organization of the gametophyte stands in the closest relation to the factors of light and moisture in the environment.
When artificially divided small fragments of the gametophyte are found to be capable of growing into new individuals.
Parallel with the evolution of the gametophyte in form and structure, a progression can be traced in the sporogonium, although the simplest sporogonia available for study may owe much of their simplicity to reduction.
Each male gametophyte form a pollen tube that penetrate the tissue of the female gametophyte.