Regulating Growth

Regulating Growth - tissues where they are produced.) The...

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Regulating Growth: Plant Hormones Plant cells are in constant chemical communication with one another and with their environment.  They recognize and respond to stimuli of many kinds, using a system of chemical messengers that  receive and transmit the stimuli via ordinary body cells (unlike the highly specialized cells of animal  nervous systems). Control of the plant system apparently resides in the genes of each cell, which are  turned on and off by the chemical messages they receive. The response may be  stimulatory  (initiating cellular division and enlargement, for example) or  inhibitory  (such as stopping a metabolic  process).  The chemical messengers are  hormones , organic substances manufactured in small amounts in  one tissue and usually transported to another where they initiate a response. (A few act in the 
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Unformatted text preview: tissues where they are produced.) The hormone molecule itself carries little information and produces a reaction only when it binds to appropriate receptor molecules at the response site. Plants, in comparison to animals, have both fewer hormones and fewer kinds of responses. Plant hormones, however, usually act in combination, thus producing more varied responses than if acting individually. The same hormone also can produce different effects when acting in different tissues or in different concentrations in the same tissue. The developmental stage of the plant additionally determines what effects the hormone activates. Growth and development depend upon a successful coordination of the activities of hormones, not just the presence or absence of individual ones....
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This note was uploaded on 11/14/2011 for the course BIO 1421 taught by Professor Farr during the Fall '08 term at Texas State.

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