DP Biology (last assessment 2024)
Question 19M.3.HL.TZ1.a
Date | May 2019 | Marks available | [Maximum mark: 1] | Reference code | 19M.3.HL.TZ1.a |
Level | HL | Paper | 3 | Time zone | TZ1 |
Command term | Outline | Question number | a | Adapted from | N/A |
a.
[Maximum mark: 1]
19M.3.HL.TZ1.a
Some halophilic bacteria biodegrade benzene, which makes them useful in treating oil spills as benzene is contained in crude oil. Investigators added cultures of the bacteria to benzene solutions at different salinities in containers. The amount of benzene remaining in the container was recorded once a week for two weeks.
[Source: adapted from C A Nicholson and B Z Fathepure, (2004),
Applied and Environmental Microbiology, 70 (2), pages 1222–1225]
Outline what is meant by halophilic when describing the bacteria.
[1]
Markscheme
thrive/live in a salt rich environment ✔
Examiners report
(a) to (c) These three questions were often answered well.
