Question

Which of the following statements is correct about plasma membrane?

• A. It allows all substances to pass into and out of cells.
• B. It prevents all substances from passing into out of cell.
• C. It is composed mainly of a protein bilayer.
• D. It is composed mainly of a lipid bilayer.

Answer 1

The correct option is D It is composed mainly of a lipid bilayer.

Plasma membrane is the outer covering of all cell but in plant cells, it is present below the cell wall. It is selectively permeable to ions and organic molecules and controls the movement of substances in and out of cells apart from cell-cell recognition. It has a host of important properties which include, fluidity, compartmentalization, transport, signaling etc.

Thus, the correct answer is option D.