Date | May 2019 | Marks available | 4 | Reference code | 19M.3.SL.TZ2.11 |
Level | Standard level | Paper | Paper 3 | Time zone | Time zone 2 |
Command term | Explain | Question number | 11 | Adapted from | N/A |
Question
Explain the use of two named bacteria in response to pollution incidents.
Markscheme
a. bacteria metabolize pollutants
OR
bacteria used in bioremediation
OR
microorganisms use pollutant as an energy source/carbon source ✔
first named bacteria:
b. name of bacterium used in bioremediation «eg: Pseudomonas» ✔ Allow any other verified example.
c. name of pollutant/substrate «eg: oil/methyl mercury» ✔
d. product of degradation «eg: CO2 and H2O/elemental mercury» ✔
second named bacteria:
e. name of bacterium used in bioremediation «eg: Marinobacter» ✔ Allow any other verified example.
f. name of pollutant/substrate «eg: benzene» ✔
g. product of degradation «eg: CO2» ✔
Award [3 max] if two bacteria are not named
Examiners report
Good explanations were given of the use of bacteria in response to pollution incidents. This was the best answered question in this option.