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I got it at www.wisegeek.com,In simple terms, the cell membrane can be thought of as the skin or protective barrier of cell.  It keeps all the internal components —  or cytoplasm — of a cell inside of it, and the external items outside of it.  Its main purpose is to maintain the integrity of the … Read more
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As I found it at www.yahooAnswers.com,A mitochondria is an organelle present in plant and animal cells. It it the energy centre which provides energy to the cell through respiration.
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As I Found it at www.wisegeek.com,Ribosomes are small organelles found in the cells of all life forms.  They are quite small, only afew hundred nanometers across. It has been theorized that ribosomeswere once independent life forms, reproducing on their own, until otherchemicals such as … Read more