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Cell : The Unit of Life

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Biology

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Biology

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CBSE Gujarat Board Haryana Board

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Class 10 Class 12
Describe the structure of centriole.

The centriole is composed of nine evenly spaced perpheral fibrils of tubulin protein. Each fibril is a triplet.  These triplets are arranged in a circle around a central hub that is proteineceous in nature.The hub is connected to the tubules by radial spokes made of protein. 

 


 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. 

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

Theodore Schwann 

State one difference between gram positive and gram negative bacteria.

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

What is the function of contractile vacuole in amoeba?

Excretion.

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

Mathias Schleiden.