Students investigated the effect of light intensity on the rate of photosynthesis by varying the distance of a lamp from a piece of pondweed. They measured the rate of photosynthesis by counting the number of oxygen bubbles produced per minute. Table 1 shows their results.
| Distance of lamp in cm | Test 1 | Test 2 | Test 3 | Mean |
|---|---|---|---|---|
| 10 | 61 | 65 | 63 | AAA |
| 20 | 41 | 43 | 42 | 42.0 |
| 30 | 25 | 24 | 26 | 25.0 |
| 40 | 12 | 31 | 14 | 13.0 |
| 50 | 6 | 7 | 5 | 6.0 |
Calculate the mean value AAA.
Identify the anomalous result in Table 1 at a distance of 40 cm.
Explain how the students used the results in Table 1 to calculate the mean value of 13.0 for the distance of 40 cm.
Practise AQA GCSE Biology 4.1 Photosynthesis with exam-style questions for Foundation and Higher tier. 17 questions covering 4.1.1 Photosynthetic reaction, 4.1.2a Rate of photosynthesis, and 4.1.3 Uses of glucose from photosynthesis, matched to the AQA GCSE Biology (8461) specification and written in Paper 1 and Paper 2 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.