Ecology and energy
Energy enters ecosystems through photosynthesis and moves up the food chain. Burning fossil fuels releases CO₂, the main gas behind global warming.
About: Ecology and energy
Energy enters ecosystems through photosynthesis and moves up the food chain. Burning fossil fuels releases CO₂, the main gas behind global warming.
Worked examples
What is the process by which plants make food using light?
Answer: Photosynthesis. In photosynthesis, plants use light, water and CO₂ to make glucose and release oxygen.
Which of these is a renewable energy source?
Answer: Solar. Solar energy is constantly renewed; coal and oil take millions of years to form.
Which human-emitted gas contributes most to the greenhouse effect?
Answer: CO₂. Carbon dioxide comes mainly from burning fossil fuels and deforestation.