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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
What are nuclear pores ? State their function.

Nuclear pores are pores in nuclear membrane. They are are formed by the fusion of its two membranes.

Functions of nuclear pores :

1. The materials are exchanged between cytoplasm and nucleus through nuclear pores.

2. The proteins are passed in and out of the nucleus through nuclear pores.

3. The enzymes for synthesis of DNA and RNA are passed into nucleus through nuclear pores.

4. Ribosomal subunits  and RNA are passed out from nucleus via nuclear pores.

5. m RNA and t RNA are passed out into cytoplasm via nuclear pores.

 


 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?

Excretion.

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.