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Receptor

/riˈseptər/ Noun 1. (Physiology) An organ or cell able to respond to light, heat, or other external stimulus and transmit a signal to a sensory nerve. (Google Dictionary) 2. A nerve ending that senses changes in light, temperature, pressure, etc., and causes the body to react in a particular way. (merriam-webster.com) 3. A cell or group of cells that receives stimuli : sense organ. (merriam-webster.com) 4. A chemical group or molecule (as a protein) on the cell surface or in the cell interior that has an affinity for a specific chemical group, molecule, or virus. (merriam-webster.com) 5. A cellular entity (as a beta-receptor or alpha-receptor) that is a postulated intermediary between a chemical agent (as a neurohormone) acting on nervous tissue and the physiological or pharmacological response. (merriam-webster.com) Word origin: From Old French receptour or directly from Latin receptor, agent noun...

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Recessive

/riˈsesiv/ Adjective 1. Tending to backward or recede. (thefreedictionary.com) 2. (Genetics) Able to be covered up by a dominant trait. (wiktionary.com) 3. (Genetics) Producing its characteristic phenotype only when its allele is identical. (wordnetweb.princeton.edu) Noun 1. A recessive allele or trait. (biology-online.org) 2. An organism whose recessive trait is discernible or expressed....

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Rectum

/ˈrektəm/ Noun, pl. recta or rectums 1. The final straight portion of the large intestine in some mammals, and the gut in others. The human rectum is about 12 centimetres (4.7 in) long, and begins at the rectosigmoid junction (the end of the sigmoid colon), at the level of the third sacral vertebra or the sacral promontory depending upon what definition is used. Its caliber is similar to that of the sigmoid colon at its commencement, but it is dilated near its termination, forming the rectal ampulla. It terminates at the level of the anorectal ring (the level of the puborectalis sling) or the dentate line, again depending upon which definition is used. In humans, the rectum is followed by the anal canal, before the gastrointestinal tract terminates at the anal verge. (wikipedia.org) 2. The last portion of the large intestine (colon) that communicates with the sigmoid colon above and the anus below. The terminal section of the alimentary canal; from the sigmoid flexure to the anus.The terminal part of the large intestine which opens to the anus. (biology-online.org) 3. The terminal part of the large intestine through which feces pass. (wiktionary.org) 4. The final section of the large intestine, terminating at the anus. (Google Dictionary) 5. The terminal section of the alimentary canal; from the sigmoid flexure to the anus (wordnetweb.princeton.edu) Word origin: From Latin intestinum rectum “straight...

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Recycling

Noun 1. A process to change (waste) materials into new products to prevent waste of potentially useful materials, reduce the consumption of fresh raw materials, reduce energy usage, reduce air pollution (from incineration) and water pollution (from landfilling) by reducing the need for “conventional” waste disposal, and lower greenhouse gas emissions as compared to plastic production. (wikipedia.org) 2. The collection and often reprocessing of discarded materials for reuse. Recycled materials include those used in manufacturing processes and those used in consumer products. The recycled material is often degraded somewhat by use or processing and therefore must be converted to another purpose. For example, the processing of recycled newspaper and other paper wastes usually shortens their fibers, and the material cannot be used to make high-grade paper. Instead, it can be reprocessed to make cardboard or insulation. Recycling helps reduce pollution, prolong the usefulness of landfills, and conserve natural resources. (thefreedictionary.com) 3. Recovery and reprocessing of waste materials for use in new products. The basic phases in recycling are the collection of waste materials, their processing or manufacture into new products, and the purchase of those products, which may then themselves be recycled. Typical materials that are recycled include iron and steel scrap, aluminum cans, glass bottles, paper, wood, and plastics. The materials reused in recycling serve as substitutes for raw materials obtained from such increasingly scarce natural resources as...

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