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hi, this confusd me a bit:"The chances of survival and development of wind blown pollen grains are much less than those of spores of adiantum.comment on this..."
The answer which I came up wid was that as the pollen grains have to find their way into the embryo or the female gametophyte so the chances are less whereas in the case of spores of adiantum they can just land at a suitably moist ground and the gametophytes will be formed and the fertilization etc will continue...
thus spores will survive better than pollen grains...also bcoz many of the pollen grains will simply not enter the female gametophyte and get wasted away whereas the spores will mostly germinate.
Is this correct?
Are there any other factors which make spores better survivors and developers?
Any help or correction fully appreciated
I don't know if I "know" the answer ot not, but it seems to me that spores are well-adapted to hanging around until the right conditions for growth just happen to show up--sometimes for years to decades or more. They have very tough exteriors resistent to water loss and are relatively resistent to temperature extremes and environmental poisons. Pollen, on the other hand, is meant to be used immediately and has very few mechanisms to avoid dessication at least, unless it successfully mates in short order. Any grains that don't mate, I guess are simply lost.
I don't know if it is true for all spores, but yeast spores can germinate and grow as haploid organisms before mating so that, too could contribute to enhanced survivability.
I think that spores of Adiantum have greater chances of surviving, because they only need a good place for sprouting, while the pollen grain needs a stigma of its spesies' flower. It may have lower chances of coming across one.
That's what I think.
Maybe the question needs another question - when and where is the pollen being released? In the middle of a paddock of its own species? Or from an isolated plant?
"What are humans if they don't learn at University? Animals, yes."
^^One of my ex-girlfriends said that. I stress the ex part.
7 posts • Page 1 of 1
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