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A space probe recently returned to Earth from a distant planet, with samples containing bacteria X - HSC - SSCE Biology - Question 29 - 2004 - Paper 1
Question 29
A space probe recently returned to Earth from a distant planet, with samples containing bacteria X. Biologists are interested in comparing the activity of an enzyme... show full transcript
Worked Solution & Example Answer:A space probe recently returned to Earth from a distant planet, with samples containing bacteria X - HSC - SSCE Biology - Question 29 - 2004 - Paper 1
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Plan an investigation you could carry out
Answer
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Materials required: Collect samples of bacteria X and bacteria E, culture media, a thermometer, pH meter, gas collection apparatus (e.g., gas syringe), and a stopwatch.
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Set up the experiment:
- Prepare culture media suitable for both bacteria and maintain a temperature of 70°C by incubating them in a water bath.
- Adjust the pH of the media to 6.5 using a pH adjuster if necessary.
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Independent variable: Type of bacteria (bacteria X and bacteria E).
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Dependent variable: Volume of gas produced over a specific time period.
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Control variables: Temperature (70°C), pH (6.5), volume of media used, and incubation time.
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Procedure:
- Inoculate separate culture media for bacteria X and bacteria E.
- Incubate both cultures for an equal duration (e.g., 30 minutes).
- Use the gas collection apparatus to measure the volume of gas produced from each culture at regular intervals.
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Repeats: Conduct the experiment three times for each type of bacteria to ensure accuracy and reliability of the results.
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Risk Assessment: Ensure to follow laboratory safety protocols when handling bacteria and measures to prevent cross-contamination.