Mutualism is relationship that is beneficial to both organisms involved. The relationship between a plant and a bacterium called a mutualism because both of them help each other. Bacteria are involved in increasing the fertility of the soil by fixing atmospheric nitrogen and thus provide plant with nitrogen. In return, the bacteria make their homes in what usually become nitrogen "nodules" along plant roots. The plant gets food, the bacteria gets shelter, everybody wins.
E. coli is C.) a bacterium that normally typically resides in a warm blooded creatures intestines or in the environment and food.
The first one is atoms cause they are all the same type of particles. The blue one is the molecules that is not compound cause they aren't connected to each other. The other two are compound cause two atoms of two different elements are bonded together.
