Tapetum

Lying immediately behind the retina, it is a retroreflector. It reflects visible light back through the retina, increasing the light available to the photoreceptors (although slightly blurring the image). The tapetum lucidum contributes to the superior . In magnoliid clade: Reproduction and life cycles …as a derived condition.

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Meaning of tapetum medical term. It refers to a special layer of cells that certain animals possess, which magnifies and enhances ambient light, enabling efficient nighttime activity. A wide variety of unrelated organisms have evolved this feature, while humans are . Tapetum definition, Botany. PURPOSE: To review, contrast, and compare current known tapetal mechanisms and review the implications for the evolution of the tapetum. Gross examination showed a weaker reflection (less shining) of the tapetum lucidum of the Siamese cats compared with common cats.

Toluidine blue sections revealed that many tapetal cells were weakly stained and giving vacuolated appearance under high magnification. Further examination with electron microscope .

It is concluded that these are subdivisions of the intracellular bundles of rodlets seen in electron micrographs. Define tapetuany of various reflective membranous layers or areas especially of the choroid and retina of the eye. Cats, dogs, and many nocturnal creatures appear to have glowing eyes because the back of their eyeballs. The protoplast of the fused tapetal cells move into the locule, where they surround the pollen mother cells or the developing pollen grains. A membranous layer of tissue.

Louis Henschel, Pierre . THE tapetum lucidum of the eye is a specialized layer lying behin but adjacent to, the light-sensitive cells of the retina. It is specialized to form a reflecting surface so that any light not absorbed during its first passage through the light- sensitive cells is reflected back again and has a second opportunity to be absorbed. This protoplast movement . As it is well known, the anther tapetum is a highly specialize transient tissue nourishing (micro-)spores and pollen grains in Bryophyta, Pteridophyta, and Spermatophyta. Enhanced contact between the . Powell says this is due to different . Synonyms: tapetal layer formation, tapetum formation.

Definition: The process that gives rise to the anther wall tapetum. The anther wall tapetum is a layer of cells that provides a source of nutrition for the pollen grains as they mature. Fisheries Laboratory, Faculty of Agriculture.

Nagoya University, Chikusa, Nagoya 46 Japan.

ABSTRACT: In several teleost fishes, guanine type ocular tapeta lucida were studied by conventional light and fluorescence microscopy. Retinatapeta lucida were found in the . The secretory tapetum is characterized by persistent cell walls and is also referred to as glandular, parietal, or cellular. In contrast, the cell walls of the amoeboid tapetum break down during microspore development. It consists of regularly arranged layers of collagen fibrils, estimated from the hydroxyproline content to make up about of the dry weight of the tissue.

There are several hundred of these layers in the . Definition of tapetum – a reflective layer of the choroid in the eyes of many animals, causing them to shine in the dark.