Describe the role of primary producers in ecosystems.

Explain the potential impact of ocean acidification on environmental systems and societies.

To what extent do anthropocentric value systems dominate the international efforts to address climate change?

Outline the factors that lead to different environmental value systems in contrasting cultures.

Explain why the harvesting of a named aquatic species may be controversial.

Discuss strategies that can be used to improve the sustainability of food production systems.

Identify four ways to ensure reliability of the mark–release–recapture method in estimating population size.

Explain how the interactions between a species and its environment give rise to the S-shape of its population growth curve.

The future growth of human populations is unlikely to be limited by the availability of energy resources. However, they could easily be limited by the impacts of energy production.

Discuss the validity of this statement.

Outline the procedures in a laboratory-based method to find the gross productivity for a population of named aquatic animals in terms of biomass per day.

Explain how acid deposition falling on a forest may impact a nearby aquatic ecosystem.

When harvesting is limited to the sustainable yield, associated processes involved in a food production system may still make the production unsustainable.

In this context, to what extent can aquatic food production systems be truly sustainable?

With reference to four different properties of a soil, outline how each can contribute to high primary productivity.

Explain how the level of primary productivity of different biomes influences their resilience.

Discuss the role of feedback mechanisms in maintaining the stability and promoting the restoration of plant communities threatened by human impacts.

Outline why top carnivores are vulnerable to non-biodegradable toxins.

Explain two factors which lead to a loss of marine (ocean) biodiversity.

Evaluate one possible pollution management strategy for solid domestic waste.

Distinguish between two named biomes and the factors that cause their distribution.

Evaluate one method for measuring primary productivity in a named ecosystem.

Discuss how human activities impact the flows and stores in the nitrogen cycle.

State the trophic level of the zebra.

State how you could determine gross secondary productivity of the zebra.

Explain how the second law of thermodynamics applies to this food chain.

State the type of relationship that exists between biting flies and the zebra.

Zebra stripes may reduce the ability of the biting flies to land on the zebra. Describe how natural selection may have led to the evolution of zebra stripes in response to biting flies.

State the ecological processes illustrated by the data in Figure 3.

Describe a method for measuring the abundance of plant species in volcanic areas.

Suggest two reasons why there are differences in the number of plant species foundon Krakatau and Tarawera.