CAIE A Level Biology 9700 · Transport in plants
Water moves from the soil into the xylem of roots via two main pathways: the apoplast pathway and the symplast pathway. Compare these two pathways for water transport from root hairs to the xylem vessels. In your answer, explain the role of the Casparian strip in the endodermis and why it is essential for the plant.
6 marks, so the mark scheme is looking for about 6 separate creditworthy points. Making the same point twice in different words earns it once.
Compare means: Give similarities or differences between two things, and say which side each point belongs to. Write each point as a pair, for example: A is X, whereas B is Y. Two separate descriptions rarely earn the marks.
Written by Markquill to follow the Cambridge International syllabus. Markquill is independent and is not affiliated with or endorsed by Cambridge International.