Biology 9700 · AS & A Level · Transport mechanisms

Transport mechanisms — practice question

Water and mineral ions travel upward through xylem vessels in the stem to reach the leaves. A proportion of the water and mineral ions leaves the xylem vessel elements and enters the parenchyma tissue in the stem.
(a)[1]

Fig. 1.1 shows a plan diagram of a stem section. Use a label line and the letter X on Fig. 1.1 to show one place where xylem tissue is found in the stem.

(b)[3]

Explain how hydrogen bonding between water molecules helps water to move upward in xylem vessels from the stem to the leaves.

(c(i))[3]

Describe and explain the pattern of water movement shown in Fig. 1.2.

(c(ii))[3]

Fig. 1.2 shows only some of the structures that can be seen with a light microscope. List the features visible at high power that let a parenchyma cell be recognised as a plant cell rather than an animal cell.

Worked solution & mark scheme

This 10-mark question has a full step-by-step worked solution and mark scheme. One marking point: Any single correct xylem position

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