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Identify TWO methods used to treat drinking water to reduce the risk of infection - HSC - SSCE Biology - Question 21 - 2011 - Paper 1
Question 21
Identify TWO methods used to treat drinking water to reduce the risk of infection. .................................................................................... show full transcript
Worked Solution & Example Answer:Identify TWO methods used to treat drinking water to reduce the risk of infection - HSC - SSCE Biology - Question 21 - 2011 - Paper 1
Step 1
Identify TWO methods used to treat drinking water to reduce the risk of infection.
Answer
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Boiling: Boiling water kills pathogens like bacteria, viruses, and protozoa, making the water safe for consumption.
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Chemical Treatment: Adding chlorine or iodine to water can effectively kill microorganisms and prevent infections.
Step 2
Outline how the use of each of these methods reduces the risk of infection.
Answer
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Boiling: By heating water to the boiling point (100°C for several minutes), harmful microorganisms are destroyed. This method is effective even in areas lacking advanced filtration systems and ensures that the water is safe to drink.
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Chemical Treatment: Chlorine or iodine introduced into the water reacts with pathogens, disrupting their cellular functions and killing them. This treatment is particularly useful in large-scale water supplies, as it provides ongoing disinfection for some time.