Question 1: Describe the main characteristics that define a tropical rainforest ecosystem.

Answer: A tropical rainforest ecosystem is characterized by high temperatures and heavy rainfall year-round, dense vegetation with tall trees forming a canopy, high biodiversity, and nutrient-poor soil due to rapid decomposition and nutrient uptake by plants.

Question 2: Explain how climate influences the distribution of ecosystems across the globe.

Answer: Climate determines temperature and precipitation patterns, which in turn influence the types of ecosystems that can thrive in an area. For example, warm, wet climates support rainforests, while cold, dry conditions support tundra. Variations in climate create the different environmental conditions necessary for diverse ecosystems.

Question 3: Identify and describe two adaptations that plants in a desert ecosystem have developed to survive in arid conditions.

Answer: Plants in deserts often have deep root systems to access underground water and thick, waxy coatings on leaves to reduce water loss. Some also have small or no leaves to minimise evaporation.

Question 4: Explain the role of decomposers in a forest ecosystem.

Answer: Decomposers, such as fungi and bacteria, break down dead organic material, recycling nutrients back into the soil, which supports plant growth and maintains the ecosystem's health.

Question 5: Draw a simple food chain that includes a producer, primary consumer, and secondary consumer in a grassland ecosystem.

Answer: A correct sketch would show: grass (producer) being eaten by a rabbit (primary consumer), which is in turn eaten by a fox (secondary consumer). The sketch should clearly label each organism.

Question 6: Describe how human activity can impact a coral reef ecosystem.

Answer: Human activities such as pollution, overfishing, and climate change can damage coral reefs. Pollution can smother corals, overfishing depletes key species, and rising sea temperatures cause coral bleaching and death.

Question 7: Sketch a cross-sectional diagram of a typical river ecosystem, indicating the flow direction and key features such as the riverbank, bed, and water surface.

Answer: A correct sketch would depict a side view of a river with arrows indicating water flow downstream, with labels for the riverbank, riverbed, water surface, and possibly features like rocks or vegetation.

Question 8: Discuss the importance of wetlands within an ecosystem and how they benefit the environment.

Answer: Wetlands act as natural filters for water, provide habitat for diverse species, control floods by absorbing excess water, and support biodiversity. They also help in carbon storage and maintaining water quality.

Question 9: Identify two threats facing tundra ecosystems and explain their impacts.

Answer: Threats include climate change, which causes permafrost melting and habitat loss, and oil exploration, which can disturb wildlife and cause pollution. Both threaten the survival of plant and animal species adapted to cold environments.

Question 10: Explain how the process of succession can lead to changes in a forest ecosystem over time.

Answer: Succession is the natural process of change in an ecosystem where pioneer species colonise an area, followed by more complex plant communities. Over time, this can lead to a mature forest with stable biodiversity, but it may also be influenced by disturbances like fire or human activity.