DP Biology (first assessment 2025)

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Question 23M.1B.SL.TZ2.3c

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Date May 2023 Marks available [Maximum mark: 2] Reference code 23M.1B.SL.TZ2.3c
Level SL Paper 1B Time zone TZ2
Command term Outline Question number c Adapted from N/A
c.
[Maximum mark: 2]
23M.1B.SL.TZ2.3c

Laboratory-scale mesocosms were built to investigate the effect of very small contaminants (nanoparticles) on ramshorn snails (Planorbarius corneus).

[Source: Material from: Auffan, M., Tella, M., Santaella, C., Brousset, L., Pailles, C., Barakat, M., Espinasse, B., Artells, E., Issartel,
J., Masion, A., Rose, J., Wiesner, M.R., Achouak, W., Thiery, A. and Bottero, J.-Y., An adaptable mesocosm platform
for performing integrated assessments of nanomaterial risk in complex environmental systems, published 2014, Nature
Scientific Reports, reproduced with permission of SNCSC.]

(c)

Outline the requirements for sustainability within a sealed mesocosm.

[2]

Markscheme
  1. photosynthetic organisms/autotrophs/plants as producers;
  2. light (as energy source) for photosynthesis;
  3. nutrient/water recycling (by saprotrophs);
  4. decomposers/saprotrophs to breakdown (toxic) wastes;

The question is “outline”, so do not accept only a list of variables without a brief account.

Syllabus sections