endosperm

endosperm

[en-duh-spurm]
noun Botany.
nutritive matter in seed-plant ovules, derived from the embryo sac.

Origin:
1840–50; < French endosperme; see endo-, sperm

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Collins
World English Dictionary
endosperm (ˈɛndəʊˌspɜːm)
 
n
the tissue within the seed of a flowering plant that surrounds and nourishes the developing embryo
 
endo'spermic
 
adj

Collins English Dictionary - Complete & Unabridged 10th Edition
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Etymonline
Word Origin & History

endosperm
c.1850, from endo- + sperm.
Online Etymology Dictionary, © 2010 Douglas Harper
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American Heritage
Science Dictionary
endosperm   (ěn'də-spûrm')  Pronunciation Key 
The tissue that surrounds and provides nourishment to the embryo in the seeds of many angiosperms. The cells of the endosperm arise from a process similar to that of fertilization. The pollen of angiosperms contains two sperm, one of which fertilizes the egg cell in the female gametophyte. The second unites with two other nuclei in the female gametophyte, producing cells that are triploid (having three sets of chromosomes) and that develop into the endosperm. In some species of angiosperms, the endosperm is absorbed by the embryo before germination, while in others it is consumed during germination. Embyros that lack an endosperm (such as peas and beans) have absorbed most of their food storage tissues before becoming dormant and develop large, fleshy cotyledons.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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Encyclopedia Britannica
Encyclopedia

endosperm

tissue that surrounds and nourishes the embryo in the angiosperm seed. The initiation of endosperm is a definitive characteristic of angiosperms and requires the fusion of at least one nucleus in the embryo sac with a sperm nucleus from the pollen grain. (In gymnosperms the nutritive material of the seed is present before fertilization.) In some seeds the endosperm has been completely absorbed at maturity (e.g., pea and bean); in others, some is present until germination (e.g., wheat, castor bean). In the coconut, the liquid endosperm contains important growth substances. Endosperm accounts for the economic importance of cereal grains and oilseeds.

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Encyclopedia Britannica, 2008. Encyclopedia Britannica Online.
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