1. Ecosystems
Species Interactions

2. What Eats What?

3. How Species Interact With Each Other
Predation: one organism kills and eats another organism
Predator/Prey – lion eats zebra, snake eats mouse
Competition: two or more organisms attempt to use the
same resource
E.g. – two plants on forest floor compete for sunlight
Parasitism: the relationship between the parasite and its host
E.g. – Ticks on a Hedgehog
Mutualism: relationship between two species in which both benefit
E.g. – Ants and Acacia Trees
Commensalism: relationship between two species in which one
benefits and the other is neither harmed nor helped
E.g. – Remora and Shark

4. Food Chain A sequence in which energy is transferred from one organism to the next as each organism eats another.

5. Food Web Shows feeding relationships in an ecosystem.

6. Trophic Level A step in the transfer of energy through an ecosystem.