write a short essay/bullet list giving at least two examples for each of the relationships in the ecosystem you have chosen. Go into detail on what is involved in the relationship, don't just list the two organisms in it.
For predator and prey, talk about how they react to each other. How does the prey either fight back or flee?
For parasite/host, what is the parasite taking from the host and how does that harm the host?
For the example where they both benefit explain how they are both benefiting.
etc.