Phototropism is a growth response by part of a plant to light.
a.[2]
Name one other tropism (excluding phototropism). Give the stimulus the plant responds to in the tropism you have named.
b.[6]
Plan an investigation to show the effect of unilateral (one-sided) light on the growth of plant shoots.
Include details of any controls needed.
You may use some of the equipment shown in Figure 1 and any other laboratory apparatus.
c.[3]
Explain how phototropism in a plant shoot helps the plant to survive.