Describe two aseptic techniques the student should have used. 1 2 Which antibiotic is the least effective? Give a reason for your answer. Least effective antibiotic Reason Calculate the area where no bacteria were growing for antibiotic C. Use $ ext{π} = 3.14$. Give the unit. Area = Unit Suggest one way the student could improve the investigation.

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Describe two aseptic techniques the student should have used - AQA - GCSE Biology - Question 8 - 2021 - Paper 1

Question 8

Describe two aseptic techniques the student should have used. 1 2 Which antibiotic is the least effective? Give a reason for your answer. Least effective antib... show full transcript

Worked Solution & Example Answer:Describe two aseptic techniques the student should have used - AQA - GCSE Biology - Question 8 - 2021 - Paper 1

Step 1

Describe two aseptic techniques the student should have used.

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Answer

Sterilize equipment and surfaces before use, ensuring that any apparatus used does not introduce unwanted microorganisms.
Secure the lid of the Petri dish with adhesive tape to prevent contamination from airborne bacteria.

Step 2

Which antibiotic is the least effective? Give a reason for your answer.

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Answer

Least effective antibiotic: Antibiotic C

Reason: It kills the fewest bacteria and has the smallest clear area where no bacteria were growing.

Step 3

Calculate the area where no bacteria were growing for antibiotic C. Use $ ext{π} = 3.14$. Give the unit.

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Answer

To calculate the area, first identify the radius based on the given information in the experiment. Assuming the diameter is 2.2 cm, the radius would be:

$r = \frac{d}{2} = \frac{2.2}{2} = 1.1 \, \text{cm}$

Then using the formula for the area of a circle:

$Area = \pi r^2$

Substituting the values:

$Area = 3.14 \times (1.1)^2 = 3.14 \times 1.21 = 3.7994 \, \text{cm}^2$

Thus, the area is approximately 3.8 cm².

Step 4

Suggest one way the student could improve the investigation.

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Answer

One way to improve the investigation is to repeat the experiment and calculate a mean result to ensure reliability. This can help to eliminate anomalies in data.

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Describe two aseptic techniques the student should have used - AQA - GCSE Biology - Question 8 - 2021 - Paper 1

Worked Solution & Example Answer:Describe two aseptic techniques the student should have used - AQA - GCSE Biology - Question 8 - 2021 - Paper 1

Describe two aseptic techniques the student should have used.

Which antibiotic is the least effective? Give a reason for your answer.

Calculate the area where no bacteria were growing for antibiotic C. Use $ ext{π} = 3.14$. Give the unit.

Suggest one way the student could improve the investigation.

Join the GCSE students using SimpleStudy...

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