The diagram depicts a xylem vessel in a root together with four neighbouring parenchyma cells. As water ascends the xylem vessel, it is replenished by water from cell D. The water in cell D is then replaced by water from cell C, which causes water to flow from cell A into the xylem. Which cell has the water potential that is least negative?
Biology 9700 · AS & A Level · Movement into and out of cells