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Endosperm in gymnosperms

  1. Feb 12, 2015 #1

    Suraj M

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    What forms the endosperm of a gymnosperm seed?? Some book said the 3 other macrospores which don't form the archegonia. I sthat right?
    i just know that the stored food is transferred from the nucellus, but where does the diploid endosperm emerge from?
     
  2. jcsd
  3. Feb 17, 2015 #2
    Thanks for the post! This is an automated courtesy bump. Sorry you aren't generating responses at the moment. Do you have any further information, come to any new conclusions or is it possible to reword the post?
     
  4. Feb 17, 2015 #3

    jim mcnamara

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    Primary endosperm (haploid tissue (n) ) is derived from the megagametophyte. The ontogenesis of primary endosperm is believed to derive from the megaprothallium in seed ferns. So, I do not know where your idea came from. See here:
    http://www.seedbiology.de/evolution.asp#jurassic
     
  5. Feb 18, 2015 #4

    Suraj M

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    oH . thanks for the link!
    But what i dont still understand is that, the megagametophyte forms the prim. endosperm and also produces the archegonia!??
    Are you reffering to the formation of endosperm from the rest of the 3 megaspores or that the food is transferred to the endosperm from the nucellus?
     
  6. Feb 18, 2015 #5

    jim mcnamara

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    Endo sperm formation. Primary endosperm is haploid. It has to derive from mitosis. It has to derive from "neighboring" haploid tissue. That is the only point I'm making. The answer to your second question is: yes you understand correctly. It forms both.

    Megagametogenesis in gynospermae: http://en.wikipedia.org/wiki/Megaspore
     
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