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Index of Subjects Dave, Thanks for the delightful follow up. I need more time in the library. -- Gerald On 6/3/14, 21:14, David & Alison Webster wrote: > Hi Again, > Yes I understood the question but I attempted to show that a > bullet-proof definition is not readily possible. As with most words, > usage and context define the meaning of a word. A first year Botany text > and a Cryptogamic Botany text would fill in the necessary context. > I vaguely recall that when exposed to this 60+ years ago we learned > about a few extinct or very rare plants that had highly modified leaves > that were almost flower-like in function and bare ovules that gave rise > to structures that were almost seeds etc. And if such intermediate > plants had not been recognized then they would have had to be postulated > to be consistent with evolution. > > Precise definitions and Biology are like oil and water. I expect many > pre-school > children would tell you that 1/2 + 1/2 does not equal 2 but the > terminology of meisosis and mitosis says that when the chromosomes of a > haploid cell fuse with those of another haploid cell then the product is > diploid. > > Is a lichen an organism ?; no. Is it alive ?;yes. Can it reproduce ?;no. > It is way past my bedtime. > Yt, Dave Webster > > > ----- Original Message ----- From: "Gerald" <naturens@zdoit.airpost.net> > To: <naturens@chebucto.ns.ca> > Sent: Tuesday, June 03, 2014 6:29 PM > Subject: Re: [NatureNS] Spores vs. seeds > > >> Dave, >> >> Thank you for the reply. I was reading Lichens of North America when I >> got confused about seeds versus spore. I did not make clear I wanted a >> text that explained seeds and spore. >> >> My difficulty is that a definiton such as yours, similar to those I >> found elsewhere, is equivocal. I'm an amateur at this. The definitions I >> found led me to conclude some seeds are spores and some spores are >> seeds, and some seeds are not spores and some spores are not seeds. That >> is, seed vs. spore is not a dichotomy. >> >> -- >> Gerald >> >> On 6/2/14, 20:25, David & Alison Webster wrote: >>> Hi Gerald & All, June 2, 2014 >>> Mainly a seed (at least a typical seed) is a multicellular non motile >>> product of sexual reproduction and has differentiated structures such as >>> cotyledons, plumule and radicle whereas spores can be single-celled or >>> multicellular, the haploid sometimes motile participants of sexual >>> union, or diploid cells or clusters of cells that are generated >>> following this union or asexual diploid cells that are just shed under >>> some conditions like a specialized single-celled botanical dandruff. >>> Many 'primitive' organisms are able to generate resting spores, when >>> conditions become adverse, so they can survive otherwise lethal >>> conditions. >>> The above are distinct from the various multicellular diploid >>> packages for vegetative propagation that are split off from lichens, >>> mosses, liverworts and some vascular plants. >>> >>> Brodo, Sharnoff and Sharnoff (Lichens of North America) is a recent >>> book with good illustrations but difficult to use because species are >>> arranged in alphabetical order so closely related genera, that might >>> readily be confused, are scattered. >>> Yt, Dave Webster, Kentville >>> >>> ----- Original Message ----- From: "Gerald" <naturens@zdoit.airpost.net> >>> To: <naturens@chebucto.ns.ca> >>> Sent: Monday, June 02, 2014 6:41 PM >>> Subject: [NatureNS] Spores vs. seeds >>> >>> >>>> Hi, >>>> >>>> I am learning about lichens. I am starting with spores (decided they >>>> came first). I am trying to understand the difference between a seed >>>> and >>>> a spore. I'm not even sure there is a difference. Answers or a good >>>> text >>>> suggestion welcome. >>>> >>>> Thanks >>>> >>>> -- >>>> Gerald >>>> >>>> >>>> ----- >>>> No virus found in this message. >>>> Checked by AVG - www.avg.com >>>> Version: 2014.0.4592 / Virus Database: 3950/7580 - Release Date: >>>> 05/28/14 >>>> >>> >> >> >> ----- >> No virus found in this message. >> Checked by AVG - www.avg.com >> Version: 2014.0.4592 / Virus Database: 3955/7617 - Release Date: 06/03/14 >> >
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