Give an example of a food chain involving four named organisms.

Mark scheme

Marking points from the official mark scheme (Oct/Nov 2014). The mark or mark type is shown in brackets.

1. [max. 4] starting with a producer ;
2. plausible food chain with 3 consumers + arrows in correct direction;
3. [max. 4] labelled pyramid with organisms named in food chain ;
4. in correct order with named producer labelled at bottom ;
5. pyramid of correct proportions for given food chain ;
6. [max. 6] some organisms/parts remain uneaten ;
7. energy lost in faeces/undigested food ;
8. urine / excretory products / excretion ;
9. respiration ;
10. energy lost as heat ;
11. homeostasis / named example ;
12. in movement / muscular contraction (or any e.g. of same);
13. in nervous impulses ;
14. catabolic reactions / named ;
15. active transport ;
16. ref. decomposition / decay