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6 (a) As the human population increases, more fossil fuels are burned - Edexcel - GCSE Biology - Question 6 - 2012 - Paper 1
Question 6
6 (a) As the human population increases, more fossil fuels are burned. The burning of coal is one of the main contributors to acid rain. (i) Complete the sentence... show full transcript
Worked Solution & Example Answer:6 (a) As the human population increases, more fossil fuels are burned - Edexcel - GCSE Biology - Question 6 - 2012 - Paper 1
Step 1
Step 2
(ii) Describe how acid rain is formed.
Answer
Acid rain is formed when sulfur dioxide (SO₂) and nitrogen oxides (NOₓ) are released into the atmosphere, primarily from burning fossil fuels. These gases react with water vapor, oxygen, and other chemicals in the atmosphere to form sulfuric and nitric acids. When it rains, these acids fall to the ground as acid rain.
Step 3
(iii) Suggest one effect acid rain has on the environment.
Answer
One effect of acid rain on the environment is that it can harm aquatic ecosystems. Acid rain lowers the pH of water bodies, which can be detrimental to fish and other aquatic organisms, leading to a decrease in biodiversity.
Step 4
(b) Explain how the quality of a river can be monitored by studying the organisms present in the water.
Answer
The quality of a river can be monitored using indicator species, which are organisms that are sensitive to changes in environmental conditions. For example, the presence of bloodworms or sludge worms indicates polluted water, while the presence of mayflies or freshwater shrimp suggests cleaner water conditions. By assessing the diversity and abundance of these species, we can infer the overall health of the aquatic ecosystem.