Question 19M.2.SL.TZ2.8b
| Date | May 2019 | Marks available | [Maximum mark: 3] | Reference code | 19M.2.SL.TZ2.8b |
| Level | SL | Paper | 2 | Time zone | TZ2 |
| Command term | Draw | Question number | b | Adapted from | N/A |
Draw a fully labelled graph of the action spectrum for photosynthesis.
[3]
a. axes correctly labelled «wavelength and rate of photosynthesis» ✔ Accept rate of oxygen production for rate of photosynthesis.
b. 400 and 700 nm as limits ✔
c. correct shape of curve involving two peaks at the correct places, broader in the blue-violet range not starting at zero and a narrower peak in the orange-red range with the trough in the green range that does not reach zero ✔
d. peaks of activity at 430 nm AND at 660 nm ✔
e. peaks indicated as «violet» blue light AND peak indicated as «orange» red light ✔
A number of students made errors in their sketches. Axes were commonly mis-labelled. The colors were commonly presented in the reverse order with red at the left end and blue at the right end. Showing red as a higher peak was another common error. The overall shape was often correctly drawn.
