Question

bacteria live in the colon of humans and are able to feed off the indigestible food that the human body cannot break down (leftovers of plants). in the process of breaking down the food, the bacteria also make much - needed vitamins that the human body in turn can use to keep healthy.
a) mutualism
b) commensalism
c) predation
d) parasitism

Explanation:

Mutualism is a symbiotic relationship where both species benefit. In this case, bacteria in the colon break down indigestible food (benefit for bacteria as they get food) and produce useful vitamins (benefit for humans). Commensalism is when one benefits and the other is neither helped nor harmed. Predation is one organism killing and eating another. Parasitism is one organism (parasite) harming another (host) while benefiting. Here, both bacteria and humans benefit, so it's mutualism.

Answer:

A. Mutualism