Question

which symbiotic interaction involves one organism feeding on or within another organism which is positive for one side of the interaction but negative for the other side?
parasitism
commensalism
mutualism
competition

Explanation:

Parasitism is a symbiotic relationship where one organism (the parasite) benefits at the expense of another (the host). Commensalism is when one organism benefits and the other is neither helped nor harmed. Mutualism is a win - win situation for both organisms. Competition is when two or more organisms compete for the same resources, not a symbiotic relationship in the same sense as the others.

Answer:

parasitism