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The human population is increasing, so more food needs to be produced - Edexcel - GCSE Biology - Question 7 - 2018 - Paper 1
Question 7
The human population is increasing, so more food needs to be produced. Farmers use fertilisers to increase the yield of wheat. A farmer wants to find out the optim... show full transcript
Worked Solution & Example Answer:The human population is increasing, so more food needs to be produced - Edexcel - GCSE Biology - Question 7 - 2018 - Paper 1
Step 1
Describe how the farmer prepares 100 cm³ of the 20% solution.
Answer
To prepare a 20% solution, the farmer first needs to measure out 20 cm³ of the concentrated stock solution, which is 100% fertiliser concentration. He then mixes this measured 20 cm³ with 80 cm³ of water to achieve a total volume of 100 cm³. This dilution results in a 20% fertiliser solution.
Step 2
Devise a plan to find the optimum percentage solution of fertiliser for the growth of these wheat plants.
Answer
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Divide the wheat plants into groups: Split the 60 wheat plants into equal-sized groups, with each group receiving a different percentage of fertiliser solution.
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Prepare various fertiliser solutions: For example, prepare 0%, 5%, 10%, 15%, and 20% solutions of fertiliser using the same method as described above.
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Monitor growth: Measure the height of the wheat plants at regular intervals (e.g., weekly) over a predetermined period (e.g., 4 weeks). Record the change in height for each group to determine their growth response to the different fertiliser concentrations.
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Analyze the data: After the observation period, calculate the average increase in height for each group, and determine which percentage solution led to the maximum growth.
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Identify the optimum solution: The optimum fertiliser concentration will be the one that resulted in the highest average growth in plant height.