DP Biology (last assessment 2024)

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Question 17N.3.HL.TZ0.a

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Date November 2017 Marks available [Maximum mark: 3] Reference code 17N.3.HL.TZ0.a
Level HL Paper 3 Time zone TZ0
Command term Outline Question number a Adapted from N/A
a.
[Maximum mark: 3]
17N.3.HL.TZ0.a

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]

Outline the emergent properties of biofilms.

[3]

Markscheme

a. properties not present in individuals but present/develop only in the aggregate

    OWTTE

b. develop structure/architecture/scaffolding

    OR

    develop an «extracellular» matrix/EPS

c. signaling/communication

d. migration/movement

e. resistant to antimicrobial agents

f. cooperates through quorum sensing

[Max 3 Marks]

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