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INSIDE LIVING THINGS
INSIDE LIVING THINGS

... INSIDE LIVING THINGS ...
Multicellular_System..
Multicellular_System..

... • Explain the common problems that multicellular organisms have. • Identify body systems in these organisms that allow them to function as a multicellular ...
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skeleton - El Camino College

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... The afferent vessel carries blood toward the gill (afferent and approach both begin with “a”). This blood is high in CO2 and low in O2. The blood in the gill exchanges gases with the water. The CO2 leaves the gill and enters the water while the O2 leaves the water and enters the gill. Then, the effe ...
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KCSE 2011 BIOLOGY

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Histology-1

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Cell theory



In biology, cell theory is a scientific theory which describes the properties of cells. These cells are the basic unit of structure in all organisms and also the basic unit of reproduction. With continual improvements made to microscopes over time, magnification technology advanced enough to discover cells in the 17th century. This discovery is largely attributed to Robert Hooke, and began the scientific study of cells, also known as cell biology. Over a century later, many debates about cells began amongst scientists. Most of these debates involved the nature of cellular regeneration, and the idea of cells as a fundamental unit of life. Cell theory was eventually formulated in 1838. This is usually credited to Matthias Schleiden and Theodor Schwann. However, many other scientists like Rudolf Virchow contributed to the theory. Cell theory has become the foundation of biology and is the most widely accepted explanation of the function of cells.The three tenets to the cell theory are as described below: All living organisms are composed of one or more cells. The cell is the most basic unit of life. All cells arise from pre-existing, living cells, by biogenesis.
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