Question 19N.3.HL.TZ0.11a
| Date | November 2019 | Marks available | [Maximum mark: 2] | Reference code | 19N.3.HL.TZ0.11a |
| Level | HL | Paper | 3 | Time zone | TZ0 |
| Command term | Outline | Question number | a | Adapted from | N/A |
Cupriavidus metallidurans CH34 is a heavy metal-resistant bacterium that was genetically modified to be used for bioremediation. The merB gene that controls the conversion of organic mercury into inorganic mercury was introduced in the bacterium. The gel electrophoresis image below shows the presence of the merB gene in two strains after 70 generations.
[Source: Copyright © 2011 Rojas LA, Yáñez C, González M, Lobos S, Smalla K, Seeger M (2011) Characterization of the
Metabolically Modified Heavy Metal-Resistant Cupriavidus metallidurans Strain MSR33 Generated for Mercury Bioremediation.
PLoS ONE 6(3): e17555. https://doi.org/10.1371/journal.pone.0017555]
Outline the aims and methods of bioremediation.
[2]
Aims [1 mark]
a. the addition of organisms to remove environmental contaminants
OR
the addition of organisms to convert toxic compounds to non-toxic products ✔
Methods [1 max]
b. physical and chemical procedures can be combined with bioremediation ✔
c. e.g. clean-up of oil spills using bacteria
OR
clean-up of heavy metals using plants and incineration ✔
Accept other valid methods involving living organisms.
Do not accept physical methods alone.
