The diagram shows a photomicrograph of the lower surface of a leaf. [Figure 1.0]

1. (a)(i)Name each of the parts labelled A to C. cell A cell B pore C[3]
2. (a)(ii)In an area affected by air pollution, the surface of the leaf becomes covered with particles. These particles reduce the amount of light entering the leaf and may block all pores of the type labelled C. Explain how this will affect the production of starch by the plant.[4]
3. (b)(i)A species of caterpillar, the holly looper, feeds on the leaves of the holly plant. Holly plants produce red berries that are eaten by a species of bird, the song thrush. Song thrushes also eat caterpillars and are eaten by hawks. Use the information above to: • Complete the food web below by writing the name of one species in each box. • Draw arrows between the boxes to show the direction of energy flow between organisms. holly [Diagram of incomplete food web][2]
4. (b)(ii)State, for the food web above, the number of: species that are producers species that are consumers trophic levels.[3]

This question uses a diagram from the original paper, which isn't shown here. Open the full paper from the past papers archive to see it.