The membrane of the erythrocytes has approximately . . . . . . $\%$ of proteins and . . . . . . $\%$ lipids.

Monovalent ions (e.g.,$Na^+, K^+$) $A$ the membrane permeability,while divalent ions $B$ the same. Complete the given statement by filling in the appropriate option for ($A$ and $B$).

The $Na^+/K^+$ pump is an example of which of the following?

Which one of the following is not present in the plasma membrane?

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

In which of the following conditions should a slice of fresh beet root release more betanin pigment?