Question 19M.1A.SL.TZ2.11
| Date | May 2019 | Marks available | [Maximum mark: 1] | Reference code | 19M.1A.SL.TZ2.11 |
| Level | SL | Paper | 1A | Time zone | TZ2 |
| Command term | Determine | Question number | 11 | Adapted from | N/A |
The graph shows the absorption spectra of chlorophyll a and chlorophyll b.
[Source: adapted from F. P. Zscheile and C. L. Comar, 'Influence of Preparative Procedure on the Purity of Chlorophyll
Components as Shown by Absorption Spectra.' Int. J. Plant Sciences, Volume 102, Number 3, Mar., 1941, pp. 463–481.
Used with the kind permission of University of Chicago Press.]
What can be concluded from the graph?
A. Both chlorophyll a and chlorophyll b absorb a large amount of green light
B. Chlorophyll b absorbs red light more efficiently than blue light
C. Other pigments must absorb light between blue and red in the spectrum
D. Chlorophyll a and chlorophyll b have different absorption peaks
[1]
D
This question discriminated very well, as most candidates realized that chlorophylls a and b have different absorption peaks. Some candidates confused the wavelengths for red and blue light therefore choosing B.
