Summary and Exam Tips for Ecosystems
Ecosystems is a subtopic of Biology, which falls under the subject Science in the Cambridge Lower Secondary curriculum. This unit explores various aspects of ecosystems, including habitats, bioaccumulation of toxic substances, and the effect of invasive species. Habitats are crucial as they provide living spaces for organisms and are sources of food and medicine. They range from rainforests, which are rich in biodiversity, to deserts and polar regions, where organisms have unique adaptations to survive extreme conditions.
The concept of bioaccumulation is illustrated through eutrophication, where runoff from fertilizers leads to algal blooms, depleting oxygen and affecting aquatic life. The effect of invasive species is exemplified by the brown tree snakes in Guam, which have disrupted local ecosystems by preying on native birds, leading to their extinction. This disruption extends to food webs, as seen with increased spider populations due to reduced bird numbers. Efforts to control invasive species include various methods, such as using predators or toxic chemicals, although challenges remain, as seen in Guam.
Exam Tips
- Understand Key Terms: Make sure you are familiar with terms like habitat, bioaccumulation, and invasive species. These are fundamental to understanding ecosystems.
- Focus on Adaptations: Pay attention to how different organisms adapt to their environments, such as desert plants storing water or polar animals surviving extreme cold.
- Ecosystem Interactions: Be able to explain how different species interact within an ecosystem and the impact of changes, such as the introduction of invasive species.
- Real-World Examples: Use examples like the brown tree snakes in Guam to illustrate the effects of invasive species on ecosystems.
- Diagram Practice: Practice drawing and interpreting diagrams that show food webs and the flow of energy in ecosystems.
