Outline one example of biological control of a named invasive species.

Explain the cause and consequences of biomagnification

a. named example of invasive species;
b. named example of biological control;

possible examples:

a. substances/pesticides/heavy metals accumulate up the food chain / at each trophic level;

b. substances cannot be metabolized/excreted;

c. these substances become concentrated in (fatty) tissues/internal organs;

d. magnified in organisms in upper part of chain as they eat more/larger organisms;

e. increase in concentration may become toxic in higher trophic levels;

f. example of a consequence of biomagnification e.g (DDT causes) thinning of egg shells (in birds);

There were some good examples given of biological control of invasive species but also many vague and non-relevant examples.

Explaining biomagnification discriminated well with all but the very weakest candidates scoring at least one mark and only the stronger candidates scoring full marks.