DP Biology (first assessment 2025)
Question 23M.1B.SL.TZ2.c
Date | May 2023 | Marks available | [Maximum mark: 2] | Reference code | 23M.1B.SL.TZ2.c |
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.c
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.]
Outline the requirements for sustainability within a sealed mesocosm.
[2]
Markscheme
- photosynthetic organisms/autotrophs/plants as producers;
- light (as energy source) for photosynthesis;
- nutrient/water recycling (by saprotrophs);
- decomposers/saprotrophs to breakdown (toxic) wastes;
The question is “outline”, so do not accept only a list of variables without a brief account.
