Describe the functions of xylem and phloem, and explain how root hair cells and xylem vessels are adapted for water and mineral transport.

Question 4:

a)
A: Phloem
B: Xylem

Question 5:

a)
K: Root hair cell
L: Xylem vessel

b) Water from the soil enters the root hair cells by osmosis due to a lower water potential inside the root cells. It then moves across the root cortex cells, either through the cytoplasm (symplast pathway) or along cell walls (apoplast pathway), until it reaches the xylem vessels (L) in the root.

c) The process by which mineral salts enter the plant is primarily active transport.

Question 6:
Two ways in which xylem are adapted to their function are:

• They have thick, lignified walls which provide structural support and prevent the vessels from collapsing, ensuring an uninterrupted water column.
• They form continuous tubes from the roots to the leaves, allowing for efficient transport of water and dissolved minerals over long distances.

Question 7:
Young herbaceous plants remain upright due to turgor pressure. When plant cells absorb water by osmosis, their vacuoles swell and push the cell membrane against the cell wall, making the cells turgid and rigid, which provides support to the plant.