Question 19M.1A.SL.TZ1.12
| Date | May 2019 | Marks available | [Maximum mark: 1] | Reference code | 19M.1A.SL.TZ1.12 |
| Level | SL | Paper | 1A | Time zone | TZ1 |
| Command term | Deduce | Question number | 12 | Adapted from | N/A |
The graph shows the effect of increasing light intensity on the rate of CO2 uptake by a species of green plant maintained in conditions of constant temperature and CO2 concentration.
[Source: © International Baccalaureate Organization 2019]
Which statement is consistent with the graph?
A. Photosynthesis stops at high light intensity.
B. Rates of photosynthesis increase with temperature.
C. Cell respiration leads to net production of CO2 at low light intensity.
D. There is a negative correlation between CO2 uptake and light intensity.
[1]
C
Many candidates (and some teachers commenting in feedback forms) chose answer A, but this is to confuse a plateau on the graph with a decrease to zero. Perhaps the term ‘rate’ was not understood and it was thought that the graph showed cumulative absorption of carbon dioxide. This is another question where more than straight factual recall is required.
