Interactions between cells always involve a structure known as a

Interactions between cells always involve a structure known as a connexins.

Explanation:

Connexins is composed of specific type of protein called transmembrane proteins. This structure is responsible for the interaction between the cells. Cells communicate with each other by secreting specific chemicals in which information is present. These chemicals consist of neurotransmitter and harmones.

well for one plants are always the producer, so a is the answer. a wolf is more of the consumer(predator) and the deer is the prey so i know those two are out of the question. also mushrooms are fungi/fungus so a is the producer.