- An animal requires food
- An animal requires shelter
- If a living thing requires something then that something has a positive impact on that living thing
- Therefore, shelter and food have positive impact on animals

- Shelter and food have positive impact on animals
- Ants are a kind of animal
- So, shelter and food have positive impact on ants

- Shelter and food have positive impact on ants
- The acacia provides shelter and food for ants
- So, the acacia providing shelter and food has a positive impact on ants

- The ants protect the acacia by removing other insects and vines that might harm it
- Protecting a living thing has a positive impact on that living thing 's survival / health
- So, the ants protecting the acacia has a positive impact on the acacia

- The acacia providing shelter and food has a positive impact on ants
- The ants protecting the acacia has a positive impact on the acacia
- Mutualism has a positive impact on both organisms in the relationship
- Hence, the relationship between the acacia and ants is mutualism

Hence, the relationship between the acacia and ants is mutualism
In Costa Rica a small tree, the acacia, provides shelter and food for ants. The ants protect the acacia by removing other insects and vines that might harm it. Which term best describes the relationship between the acacia and the ants?
- The acacia provides shelter and food for ants 
- The ants protect the acacia by removing other insects and vines that might harm it 
- An animal requires food 
- Mutualism has a positive impact on both organisms in the relationship 
- An animal requires shelter 
- If a living thing requires something then that something has a positive impact on that living thing 
- Ants are a kind of animal 
- Protecting a living thing has a positive impact on that living thing 's survival / health