There is considerable variation in the ecosystems that occur in the continent of North America. These include coniferous forest, prairie grassland, scrub and desert. Large areas of land that once contained natural ecosystems are now used for agriculture.

Section B Answer one question. (a) Explain what is meant by the terms ecosystem and niche.

The aye-aye, Daubentonia madagascariensis, is a primate native to Madagascar. Aye-ayes are nocturnal (active at night...

Fig. 7.1 shows a red deer, Cervus elaphus. Red deer are herbivores that feed on a wide range of plants. [Figure 7.1] ...

Which diagram correctly shows hydrogen bonding between two water molecules? [Figure 13.1]

Which statement describes an example of an extracellular enzyme?

Which row is correct for enzymes that catalyse reactions using the lock-and-key hypothesis?