IGCSE marine science section 4 4 part 1

Covering the first part of the 4.4 syllabus:

1 state that the Sun is the principal source of energy input to biological systems 

2 describe a food chain as showing the transfer of energy from one organism to the next, beginning with a producer

 3 describe a food web as a network of interconnected food chains 

4 construct food chains and food webs to represent and interpret feeding relationships in marine ecosystems 

5 describe a trophic level as the position of an organism in a food chain, food web or ecological pyramid

6 describe a consumer as an organism that gets its energy by feeding on other organisms

 7 state that consumers may be classed as primary, secondary and tertiary according to their position in a food chain, and that they can feed at different trophic levels in a food web 

8 describe different types of consumer

(a) a herbivore as an animal that gets its energy by eating producers 

(b) a carnivore as an animal that gets its energy by eating other animals 

(c) an omnivore as an animal that gets its energy by eating plants and other animals 

(d) a detritivore as an animal that gets its energy from eating dead or waste organic material

9 describe a decomposer as an organism that gets its energy by breaking down dead or waste organic material 

10 describe a predator as an animal that captures, kills and eats another animal, which is its prey 

My notes are here:

Crash courses video is also great for references

This video from AS Marine science also covers a lot of the same ground