A seed or seed (like Latin semen : 'seed', 'seedling', 'the dropped one', from Indo-European root sēi , 'dispatch', 'throw', and related to sowing ) is a tissue structure of the seed plants that serves to spread ( Spermatophyta), which consists of a seed coat (testa), the embryo and often a nutrient tissue ( endosperm or perisperm ). So that the seed contains all the facilities to under favorable germination conditions for a new plant to grow.
Semen are formed after an egg cell sitting in the ovule has been fertilized by a generative cell of a pollen grain. The fertilized egg cell ( zygote ) turns into a plant embryo through mitotic cell division , which does not continue to grow, but is held in a kind of temporary waiting position through partial desiccation.
There are significant differences in detail between
- Gymnosperms (gymnosperms): The seed is exposed and is not of a fruit wall ( pericarp enclosed).
- Bedecktsamern (Angiospermae): The seed lies in the ovary (carpel) and is therefore enclosed by a pericarp.
- Propagation mechanisms of plants
- Dormancy , growth (biology)
- Germination , dormancy , light germination , field emergence
- Seed library , seed bank
- Stratification (botany) , vernalization
- Thousand grain weight
- Friedrich Kluge , Alfred Götze : Etymological dictionary of the German language . 20th edition. Edited by Walther Mitzka , De Gruyter, Berlin / New York 1967; Reprint (“21st unchanged edition”) ibid 1975, ISBN 3-11-005709-3 , p. 622 f.
- The dictionary of origin (= Der Duden in twelve volumes . Volume 7 ). 5th edition. Dudenverlag, Berlin 2014 ( p. 716 ). See also DWDS ( "seeds" ) and Friedrich Kluge: Etymological dictionary of the German language . 7th edition. Trübner, Strasbourg 1910 ( p. 384 ).
- Neil A. Campbell, Jane B. Reece: Biology. 8th edition, Pearson, Munich a. a., 2009, p. 1836.