The nature of the plasma membrane is:

Which of the following is not a component of the cell membrane?

Which one of the following is not a constituent of cell membrane?

The sodium-potassium pump is:

$A -$ $A$ cell is a closed compartment for all substances.
$R -$ Plasma membrane of a cell is selectively permeable.

Assertion : $A$ cell membrane shows fluid behaviour.
Reason : $A$ membrane is a mosaic or composite of diverse lipids and proteins.