Edexcel IGCSE Biology · Spec 4.16-4.18B
Water Pollution and Deforestation
How eutrophication pollutes water, and the environmental impact of deforestation.
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Water Pollution and Deforestation
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Spec 4.16-4.18B
What you need to know
- Describe pollution of water by sewage
- Explain eutrophication
- Describe the effects of deforestation
Active recall
Quick check
Answer each question before opening the answer.
How does fertiliser run-off cause eutrophication?
Nitrates cause algae to bloom, blocking light so plants die; bacteria decompose them, using up the oxygen, so aquatic organisms die.
State two effects of deforestation.
Any two of: less carbon dioxide removed (more warming), soil erosion, flooding, loss of biodiversity/habitats.
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