DP Biology (last assessment 2024)
Question 17N.3.HL.TZ0.b
Date | November 2017 | Marks available | [Maximum mark: 1] | Reference code | 17N.3.HL.TZ0.b |
Level | HL | Paper | 3 | Time zone | TZ0 |
Command term | State | Question number | b | Adapted from | N/A |
b.
[Maximum mark: 1]
17N.3.HL.TZ0.b
The scanning electron micrograph shows a biofilm on a metal surface from an industrial water system.
[Source: Biofilms: Survival Mechanisms of Clinically Relevant Microorganisms, Rodney M. Donlan, J. William Costerton, Clinical Microbiology Reviews, 2002, 15 (2), pp. 167–193. Reproduced with permission from American Society for Microbiology]
State a positive application of biofilms.
[1]
Markscheme
a. sewage/waste water treatment/trickle filter beds
b. «bio»remediation of contaminated soil/water
c. metal extraction from ore deposits/microbial leaching
Accept other valid positive application
eg: decay/breakdown contaminants, such as petroleum
[Max 1 Mark]
