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Cell : The Unit of Life

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CBSE Gujarat Board Haryana Board

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Class 10 Class 12
 “The function of an organism is the sum result of the sum total of activities and interactions of constituent cells”. Comment.

An oganisms has billions or trillions of cells. Cells performing similar functions are grouped together to form tissue. The different tissue perform different functions. These different activities work together to sustain lie in a multicellualr organisms. Since, the main constituent of the any organism is a cell that is capable of all activities of life, we can say that the functions of an organism are sum total of functions performed by constituent cells.

State one difference between gram positive and gram negative bacteria.

Gram positive bacteria retains the gram stain whereas the Gram negative bacteria does not. 

Who reported that the cell had an outer layer which is known as plasma membrane today?

Theodore Schwann 

Who concluded, “Cells are the ultimate units forming the structure of all plant tissues”?

Mathias Schleiden.

 What are receptor molecules ?

Receptor molecules are specific proteins in the cell's plasma membrane that receive chemical signals from outside the cell. When such chemical signals bind to a receptor, they cause some form of cellular response. 

What is the function of contractile vacuole in amoeba?