DP Biology (last assessment 2024)
Question 23M.3.SL.TZ1.15
Date | May 2023 | Marks available | [Maximum mark: 4] | Reference code | 23M.3.SL.TZ1.15 |
Level | SL | Paper | 3 | Time zone | TZ1 |
Command term | Explain | Question number | 15 | Adapted from | N/A |
15.
[Maximum mark: 4]
23M.3.SL.TZ1.15
Explain the consequences of plastic pollution in marine environments.
[4]
Markscheme
- animals may get entangled in plastic and cannot breathe/swim;
- macroplastics/plastics can be ingested as food
OR
used to feed chicks; - which may block their gut/cause death;
- macroplastics broken down to microplastics
OR
(micro)plastics may release toxic chemicals; - DDT/pesticides/heavy metals;
- microplastics/toxic chemicals may accumulate in tissues/bioaccumulate;
- microplastics/toxic chemicals build up along food chain/in higher trophic levels/biomagnification;
- plastics persist for a long time in the environment;
Examiners report
This was generally well answered with the majority of candidates mentioning entanglement and feeding on plastic and nearly all gaining one or more marks. Biomagnification and bioaccumulation were also well understood.
