stoma

Lemma

stoma

Etichetta di dominio

EN

Etichetta grammaticale

n.; pl. stomata

Definizione

One of the minute pores in the epidermis of a leaf or stem through which gases and water vapor pass. 1

Nota

Stomata permit the absorption of carbon dioxide necessary for photosynthesis from the air, as well as the removal of excess oxygen. Stomata occur on all living plant parts that have contact with the air; they are especially abundant on leaves. A single leaf may have many thousands of stomata. Each stoma is generally between 10 to 30 microns in length and is surrounded by a pair of crescent-shaped cells, called guard cells. The guard cells can change shape and close the stoma in order to prevent the loss of water vapor. 2

Contesto

Since the stomata are the entry points for carbon used in photosynthesis, severe water deficits limit the time the stomata are open which limits the photosynthesis and the production of sugar leading to poor fruit quality and reduced yeld. 3

Trascrizione fonetica

UK [ˈstəʊmə], US [ˈstoʊmə] 4

Sinonimi e Antonimi
ND
Abbreviazioni
ND
Etimologia

"orifice, small opening in an animal body," 1684, from Mod.L., from Gk. stoma (gen. stomatos) "mouth," from PIE base *stom-en-, denoting various body parts and orifices (cf. Avestan staman- "mouth" (of a dog), Hittite shtamar "mouth," M.Bret. staffn "mouth, jawbone," Corn. stefenic "palate"). Surgical sense is attested from 1937. 3

Etichetta di paese
ND
Ente

Università degli Studi di Genova, Facoltà di Lingue e Letterature Straniere, Corso di Laurea in Teorie e Tecniche della Medizione Interlinguistica

Data della scheda
Tue Sep 23 00:00:00 2008
Autore

Chiara Martini, rev. Chiara Barbagianni

Fonti

1 : «http://science.yourdictionary.com/stoma», (27/10/2011)

2 : «http://science.yourdictionary.com/stoma», (27/10/2011)

3 : «http://ucanr.org/sites/CE_San_Joaquin/files/35488.pdf», (27/10/2011)

4 : «http://dictionary.cambridge.org/dictionary/british/stoma?q=stoma», (27/10/2011)

5 : «http://www.etymonline.com/index.php?search=stoma&searchmode=none», (14/08/2008)

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