Edexcel IGCSE Biology 2.42B leaf gas exchange adaptations

Practise linking leaf structure to gas exchange by explaining how tissues and cell arrangements support movement of gases and photosynthesis.

Exam points

explain how named leaf layers support gas exchange and photosynthesis
link leaf structure to surface area, chloroplasts and movement of gases

[Maximum number: 2]

The diagram shows a section through a leaf with different parts labelled P to U .

Figure for Question 2.42B Leaf adaptations for gas exchange question 1 — Edexcel IGCSE Biology

The photograph shows water lilies, plants that float on the surface of ponds.

Suggest why the leaves of the water lily only have stomata on their upper surface.

An answer that makes reference to two the following points:

- lower surface in water / upper in air / stomata would be in water / eq

- (stomata) able to absorb $\mathrm{CO}_{2} /$ gases (by diffusion) / allows gas exchange

- (stomata) able to lose water (by transpiration / evaporation) / to allow transpiration

All question bank results loaded

2.42B Leaf adaptations for gas exchange question 1