Question 2.3.1:
(a) The dependent variable: Number of bubbles formed per minute
(b) How the dependent variable was measured: Counting the number of bubbles released by the water plant
(c) The independent variable: Distance between the lamp and plant
(d) How the independent variable was varied: By changing the distance between the lamp and plant at regular intervals
Question 2.3.2:
The function of sodium bicarbonate in this investigation is to provide the water plant with a source of carbon dioxide for photosynthesis.
Question 2.3.3:
One way in which the reliability of the investigation could be increased is by repeating the experiment multiple times and taking the average of the results to minimize the impact of any anomalies.
Question 2.3.4:
(please note that this will be a textual representation of a graph)
Distance (mm) | Bubbles formed per minute
40 | 32
80 | 30
120 | 28
160 | 25
200 | 15
240 | 10
280 | 5
320 | 3
360 | 0
(The line graph should have Distance on the x-axis and Number of bubbles formed per minute on the y-axis, with the data points plotted accordingly)
The apparatus shown below was used in an investigation to determine the effect of light intensity on the rate of photosynthesis.
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The distance between the light source (lamp) and the apparatus (with a water plant) was changed at regular intervals, recording the number of bubbles released by the water plant at each distance.
The results are shown in the table below.
Distance between lamp and plant (mm)
40
80
120
160
200
240
280
320
360
Bubbles formed per minute
32
30
28
25
15
10
5
3
0
Question 2.3.1 [4 marks]
For the above investigation, state:
(a) The dependent variable
(b) How the dependent variable was measured (c) The independent variable
(d) How the independent variable was varied
Question 2.3.2 [1 mark]
State the function of sodium bicarbonate in this investigation.
Question 2.3.3 [1 mark]
State ONE way in which the reliability of the investigation could be increased. Question 2.3.4 [8 marks]
Plot a line graph to represent the data obtained during this investigation.
[14 marks]
1 answer
1 answer