Which pair of features is correct for both diffusion and osmosis?
▶️Answer/Explanation
The correct answer is D, that both diffusion and osmosis occur due to a concentration gradient and do not require energy input from the cell.
Diffusion is the movement of molecules from an area of high concentration to an area of low concentration, down a concentration gradient. Similarly, osmosis is the movement of water molecules from an area of high concentration to an area of low concentration, down a concentration gradient.
How do mineral ions in the soil move into the root?
A. Osmosis
B. Mass flow of water
C. Translocation
D. Through phloem
Answer/Explanation
Markscheme ; B
The correct answer is:
B. Mass flow of water
Explanation:
A is incorrect: Osmosis refers to the movement of water, not mineral ions. Osmosis occurs when water moves from an area of low solute concentration to high solute concentration across a semi-permeable membrane.
B is correct: Mineral ions dissolve in water and move toward the root via the mass flow of water in the soil. This movement is driven by water uptake through transpiration pull in the plant.
C is incorrect: Translocation refers to the movement of sugars and organic molecules through the phloem, not mineral ions.
D is incorrect: Mineral ions do not travel through the phloem; instead, they enter the root via active transport or facilitated diffusion and move through the xylem to reach different parts of the plant.
Which process and cause are responsible for water uptake by the roots?
Answer/Explanation
Markscheme
B