Which of the following statement is correct regarding cell membrane?
I. The membrane is selectively permeable to some molecules present on either side of it.
Il. Water may also move across this membrane from lower to higher concentration.

Correct option is B

The correct answer is (b) Only I.
• Statement I is correct because the cell membrane is selectively permeable, meaning it allows certain molecules or ions to pass through it by means of active or passive transport.
• Statement II is incorrect because water typically moves across the cell membrane from an area of higher concentration to an area of lower concentration, a process known as osmosis. Water moving from lower to higher concentration would require energy input and is not a common occurrence in natural cellular processes.
Information Booster:
• Selective permeability: This feature allows the cell membrane to maintain homeostasis by regulating the internal environment.
• Osmosis: The diffusion of water across a selectively permeable membrane from a region of higher water concentration to a region of lower water concentration.
• Active transport: The movement of molecules across the cell membrane using energy, typically against their concentration gradient.
• Passive transport: The movement of molecules across the cell membrane without the use of energy, following their concentration gradient.