wikipedia mostly
Feb. 24th, 2008 10:00 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
eubDidn't want to do anything. Didn't want to do nothing. Mope around. Read up on plant reproduction -- maybe it still won't stick, but it keeps the brain from sitting like a lump.
gametophyte: haploid. fusion of gametes produces zygote which develops into sporophyte.
sporophyte: diploid. meiosis produces spores which develop into gametophyte.
in bryophytes, the gametophyte is what we think of as moss; sporophyte generation is stalks growing atop (bearing sporangia).
some mosses are dioecious, some monoecious. sperm swims from antheridium to archegonium; zygote typ. develops there.
in vascular plants, sporophyte is dominant form.
fern spore develops into prothallus: small plant, a few mm in size. (mono/dioecious?) after fusion to zygote, sporophyte develops on the spot?
in flowering plants, male gametophyte in pollen and female in ovule. zygote embryo in seed.
gymnosperm megagametophyte (female) is thousands of cells, forms archegonia.
angiosperm megagametophyte is typ. seven cells: egg cell, two synergids, central cell with two polar nuclei, three antipodals.
pollen tube introduces two sperm nuclei. in angiosperms, one fuses with egg cell to form zygote; one fuses with the two nuclei of the central cell to form endosperm -- triploid. (in gymnosperms, one is forgotten?)
pollen grain consists of vegetative cells, one germ cell, which has two nuclei. tube nucleus produces pollen tube; generative nucleus divides to form two sperm cells.
most sperm non-motile, cycad and gingko have many-flagellated.
(cycads aren'tbugsferns!)
cycads have nitrogen-fixing Nostoc cyanobacteria in their roots.
these produce beta-methylamino-L-alanine, found in cycad seeds, neurotoxin perh. causing Lytico-Bodig on Guam (after concentration in meat of fruit bats -- Sacks).
Nostoc (flagelliforme, commune, ellipsosporum) cultivated and eaten.
http://en.wikipedia.org/wiki/Fat_choy_(vegetable)
http://waynesword.palomar.edu/cyano1.htm
http://www.live-in-green.com/features/nostoc.html
gametophyte: haploid. fusion of gametes produces zygote which develops into sporophyte.
sporophyte: diploid. meiosis produces spores which develop into gametophyte.
in bryophytes, the gametophyte is what we think of as moss; sporophyte generation is stalks growing atop (bearing sporangia).
some mosses are dioecious, some monoecious. sperm swims from antheridium to archegonium; zygote typ. develops there.
in vascular plants, sporophyte is dominant form.
fern spore develops into prothallus: small plant, a few mm in size. (mono/dioecious?) after fusion to zygote, sporophyte develops on the spot?
in flowering plants, male gametophyte in pollen and female in ovule. zygote embryo in seed.
gymnosperm megagametophyte (female) is thousands of cells, forms archegonia.
angiosperm megagametophyte is typ. seven cells: egg cell, two synergids, central cell with two polar nuclei, three antipodals.
pollen tube introduces two sperm nuclei. in angiosperms, one fuses with egg cell to form zygote; one fuses with the two nuclei of the central cell to form endosperm -- triploid. (in gymnosperms, one is forgotten?)
pollen grain consists of vegetative cells, one germ cell, which has two nuclei. tube nucleus produces pollen tube; generative nucleus divides to form two sperm cells.
most sperm non-motile, cycad and gingko have many-flagellated.
(cycads aren't
cycads have nitrogen-fixing Nostoc cyanobacteria in their roots.
these produce beta-methylamino-L-alanine, found in cycad seeds, neurotoxin perh. causing Lytico-Bodig on Guam (after concentration in meat of fruit bats -- Sacks).
Nostoc (flagelliforme, commune, ellipsosporum) cultivated and eaten.
http://en.wikipedia.org/wiki/Fat_choy_(vegetable)
http://waynesword.palomar.edu/cyano1.htm
http://www.live-in-green.com/features/nostoc.html
![[identity profile]](https://www.dreamwidth.org/img/silk/identity/openid.png){kind=small}
no subject
Date: 2008-02-25 06:42 am (UTC)I had that day, too. I did laundry, and planted a new rosemary.