Question

Exchange of substances between a cell and its environment is mediated through

• A. Osmosis
• B. Active transport
• C. Diffusion
• D. All the above

Answer 1

Answer: (D)

All the above

Exchange of substances between a cell and its environment is mediated through osmosis, active transport and diffusion.

Osmosis is the process of diffusion of molecules from the region of higher concentration to the lower concentration through a semipermeable membrane. The cells absorb water by the process of endosmosis from its surrounding and water exits by the process of exosmosis.

Active transport is the transport which requires energy and helps to transfer molecules from region of low concentration to high concentration. Water and minerals ions are inorganic material present in the soil. They exist mainly in ionic form because the root hair absorbs the mineral by passive absorption to outer space like intercellular space and cell wall but for absorption into the inner space like cytoplasm and the vacuoles, it needs active transport which required ions to create a concentration gradient.

Diffusion is random movement of molecules from the region of higher concentration to the lower concentration. It allows the gaseous exchange during transpiration from the stomata.

So, the correct answer is option D.