How do you think he fits into and interacts with these systems? write a detailed description of how this bear interacts with each of the systems.

Systems? As in ecosystem? Food system? Regardless. He is top of the food-chain. So, he stops overpopulation, which is big in an ecosystem for many reasons. It keeps the balance between animal and supply of food. Too many rabbits, not enough grass. Not enough bears, too many fish. Too many salmon. Too many salmon, not enough food for other fish. Etc.

Everything that you need in a lab is in your lab