Plants need light for photosynthesis - Edexcel - GCSE Biology Combined Science - Question 1 - 2016 - Paper 1
Question 1
Plants need light for photosynthesis.
Part of the photosynthesis equation is shown below.
------------------- + carbon dioxide → glucose + -------------------
(a) ... show full transcript
Worked Solution & Example Answer:Plants need light for photosynthesis - Edexcel - GCSE Biology Combined Science - Question 1 - 2016 - Paper 1
Step 1
Which of the following would complete the photosynthesis equation?
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Answer
The correctly completed photosynthesis equation is:
ightarrow ext{glucose} + ext{oxygen}$$
Thus, the answer is C: water and oxygen.
Step 2
State three variables that should be kept constant to improve the results.
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Answer
To ensure a fair test, the following variables should be kept constant:
Temperature of the water - This could be controlled by using a water bath.
Amount of water in the test tube - Use the same volume for each test.
Type of plant used - Use the same species and size of plant for all trials.
Step 3
Give one improvement the scientist could make to reduce the effect of this increase in temperature.
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Answer
To reduce the effect of increased water temperature, the scientist could place a heat shield between the lamp and the water to absorb excess heat.
Step 4
Calculate the mean result for a distance of 20cm.
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Answer
To calculate the mean for the distance of 20cm, we take the results from test 1, test 2, and test 3:
Therefore, the mean result for a distance of 20cm is 23 bubbles.
Step 5
State how the scientist could deal with this anomaly.
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The scientist could deal with the anomaly by repeating the test for that specific distance (10cm) to gather more data and potentially identify if that count was an outlier.
