Which of the following statements is correct regarding cell membranes?
I. The membrane is selectively permeable to some molecules present on either side of it.
II. Water may also move across this membrane from lower to higher concentration.
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. Only I.
The correct statement regarding cell membranes is:
I. The membrane is selectively permeable to some molecules present on either side of it.
Explanation:
- Statement I: This is correct. Cell membranes are selectively permeable, permitting certain molecules or ions to cross via active or passive transport while preventing others from passing through. This selective permeability is crucial for maintaining the proper balance of ions, nutrients, and other substances within the cell.
- Statement II: This statement is partially incorrect. Water typically moves across the cell membrane from an area of lower solute concentration to an area of higher solute concentration through a process called osmosis. This movement is towards higher solute concentration, not necessarily higher water concentration, which is a common misconception.
Thus, Statement I is correct, while Statement II is inaccurate in its description of water movement across the membrane.