Complete Fig. 2.1 by labelling plant structure B and the process occurring between C and D.
The flowers make nectar in nectaries and are pollinated by insects such as bees. Suggest where the nectaries are situated and how this helps pollination.
After pollination, pollen tubes grow down the style. Describe what happens next leading to the formation of B and what it contains.
Coffea arabica plants make a chemical called caffeine which, in high concentrations, is toxic to insects. Suggest why making caffeine is useful to the plant.
Caffeine occurs throughout the plant, but the concentration is much greater in some parts than in others. Suggest why it is important for the plant to have different concentrations in different parts.
Using caffeine and adrenaline as examples, explain how a drug differs from a hormone.
Suggest two effects on the body after drinking coffee that contains caffeine.