The total magnification achieved using a 10× objective lens with a 10× eyepiece lens is 20×.

True or False?

Choice A rationale: Low, high is incorrect because it is the opposite of the direction of simple diffusion. Simple diffusion is the passive movement of molecules along their concentration gradient, which means from high to low concentration.

Choice B rationale: Low, equal is incorrect because it is not the final state of simple diffusion. Simple diffusion will continue until the concentration of molecules is equal on both sides of the membrane.

Choice C rationale: Equal, low is incorrect because it is not possible for simple diffusion. Simple diffusion will stop when the concentration of molecules is equal on both sides of the membrane, and there will be no net movement of molecules.

Choice D rationale: Equal, high is incorrect because it is not possible for simple diffusion. Simple diffusion will stop when the concentration of molecules is equal on both sides of the membrane, and there will be no net movement of molecules.

Choice E rationale: High, low is correct because it is the definition of simple diffusion. Simple diffusion is the passive movement of molecules along their concentration gradient, which means from high to low concentration.

Choice A rationale: An isotonic solution has the same solute concentration as the plant cells, which means it has the same water potential. Water will move in and out of the plant cells at the same rate, causing them to remain unchanged in size and shape. This will not help the lettuce to become less wilted.

Choice B rationale: A hypertonic solution has a higher solute concentration than the plant cells, which means it has a lower water potential. Water will move out of the plant cells by osmosis, causing them to shrink and become plasmolysed. This will make the lettuce more wilted and not crisper.

Choice C rationale: Soaking the lettuce in water would have an effect, depending on the relative solute concentration of the water and the plant cells. Water will move across the cell membrane by osmosis, either into or out of the plant cells, causing them to change in size and shape.

Choice D rationale: A hypotonic solution has a lower solute concentration than the plant cells, which means it has a higher water potential. Water will move into the plant cells by osmosis, causing them to swell and become turgid. This will make the lettuce crisper and more appealing.

Choice E rationale: A hypotonic solution will cause the plant cells to gain water and become turgid, not more wilted. Wilted lettuce is caused by the loss of water from the plant cells, which makes them flaccid and soft.