Cells of an alga were placed in a solution with the same concentration as the cell contents. The concentration of magnesium ions in the solution was lower than in the cells, but the cells still absorbed magnesium ions. Which statement describes the movement of water and of magnesium ions?
There was no net movement of water, and magnesium ions moved against their concentration gradient.
Water moved out of the cells, and magnesium ions moved against their concentration gradient.
Water moved into the cells, and magnesium ions diffused down their concentration gradient.
There was no net movement of water, and magnesium ions diffused down their concentration gradient.
140 exam-style questions on AQA GCSE Biology 1.3 Transport in cells, covering 1.3.1 Diffusion, 1.3.2 Osmosis, and 1.3.3 Active transport. Each one has a worked solution and a mark scheme showing where the marks go.