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tapetum
tapetum In many nocturnal mammals, a layer of cells either in the retina or outside it, in the choroid (e.g. in cats), which contain crystals of zinc and a protein (often riboflavin, which fluoresces). The tapetum reflects light back through the retina and so increases the sensitivity of the eye to dim light. At night, when the pupil is fully dilated, reflected light from the tapetum will cause ‘night shine’ if the animal turns to look in the direction of a sudden bright light (e.g. car headlights).
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Cite this article
MICHAEL ALLABY. "tapetum." A Dictionary of Ecology. 2004. Encyclopedia.com. 30 May. 2012 <http://www.encyclopedia.com>. MICHAEL ALLABY. "tapetum." A Dictionary of Ecology. 2004. Encyclopedia.com. (May 30, 2012). http://www.encyclopedia.com/doc/1O14-tapetum.html MICHAEL ALLABY. "tapetum." A Dictionary of Ecology. 2004. Retrieved May 30, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O14-tapetum.html |
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tapetum
tapetum In many nocturnal mammals, a layer of cells either in the retina or outside it, in the choroid (e.g. in cats), that contain crystals of zinc and a protein (often riboflavin, which fluoresces). The tapetum reflects light back through the retina and so increases the sensitivity of the eye to dim light. At night, when the pupil is fully dilated, reflected light from the tapetum will cause ‘night shine’ if the animal turns to look in the direction of a sudden bright light (e.g. car headlights).
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Cite this article
MICHAEL ALLABY. "tapetum." A Dictionary of Zoology. 1999. Encyclopedia.com. 30 May. 2012 <http://www.encyclopedia.com>. MICHAEL ALLABY. "tapetum." A Dictionary of Zoology. 1999. Encyclopedia.com. (May 30, 2012). http://www.encyclopedia.com/doc/1O8-tapetum.html MICHAEL ALLABY. "tapetum." A Dictionary of Zoology. 1999. Retrieved May 30, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O8-tapetum.html |
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tapetum
tapetum A layer of cells, rich in food, which surrounds the spore mother cells in Tracheophyta (e.g. in the pollen sacs of the anther in a fern sporangium). This layer may either break down to form the periplasmodium, a fluid that is absorbed by the developing microspores, or it may last longer, breaking down shortly before anther dehiscence and secreting substances into the locule.
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MICHAEL ALLABY. "tapetum." A Dictionary of Plant Sciences. 1998. Encyclopedia.com. 30 May. 2012 <http://www.encyclopedia.com>. MICHAEL ALLABY. "tapetum." A Dictionary of Plant Sciences. 1998. Encyclopedia.com. (May 30, 2012). http://www.encyclopedia.com/doc/1O7-tapetum.html MICHAEL ALLABY. "tapetum." A Dictionary of Plant Sciences. 1998. Retrieved May 30, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O7-tapetum.html |
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tapetum
tapetum A reflecting layer, containing crystals of guanine, in the choroid of the eye of many nocturnal vertebrates. It reflects light back onto the retina, thus improving vision and causing the eyes to shine in the dark.
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Cite this article
"tapetum." A Dictionary of Biology. 2004. Encyclopedia.com. 30 May. 2012 <http://www.encyclopedia.com>. "tapetum." A Dictionary of Biology. 2004. Encyclopedia.com. (May 30, 2012). http://www.encyclopedia.com/doc/1O6-tapetum.html "tapetum." A Dictionary of Biology. 2004. Retrieved May 30, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O6-tapetum.html |
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