Biology 9700 · AS & A Level · Transport mechanisms

Transport mechanisms — practice question

Fig. 1.1 and Fig. 1.2 show photomicrographs of cross-sections through the leaves of two different plants. Fig. 1.1 is a photomicrograph of a section through a leaf of Cornish heath, Erica vagans. Fig. 1.2 is a photomicrograph of a section through a leaf of Himalayan cedar, Cedrus deodara. Fig. 1.1 and Fig. 1.2 are not shown at the same magnification.
(a)[3]

Cells labelled A, B and C in Fig. 1.1 and Fig. 1.2 each make up a different tissue. Name the tissue produced by each cell. - tissue produced by A - tissue produced by B - tissue produced by C

(b)[3]

Erica vagans and Cedrus deodara are xerophytic plants. Using only xerophytic features, describe how the leaves of E. vagans and C. deodara differ in Fig. 1.1 and Fig. 1.2.

(c)[3]

Transpiration is a result of gas exchange in leaves. Explain why the rate of transpiration is higher during the day than during the night.

Worked solution & mark scheme

This 9-mark question has a full step-by-step worked solution and mark scheme. One marking point: A is the palisade mesophyll

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