THE CELL
CELL THEORY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Hand lens
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Compound light microscope
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Electron microscope
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Scanning tunneling microscope
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Detailed explanation-1: -Cells can only be seen with a microscope.
Detailed explanation-2: -The classical cell theory was proposed by Theodor Schwann in 1839. There are three parts to this theory. The first part states that all organisms are made of cells. The second part states that cells are the basic units of life.
Detailed explanation-3: -The cell theory states that all biological organisms are composed of cells; cells are the unit of life and all life come from preexisting life. The cell theory is so established today that it forms one of the unifying principles of biology.
Detailed explanation-4: -The cell theory was proposed by two scientists-Schleiden (1838)and Schwann (1839). It says that all the plants and animals are composed of cells and the cell is the basic unit of life. The cell theory was further expanded by Virchow (1855) by suggesting that all cells arise from pre-existing cells.