Ecology Essay Question

How can a change in the population of one species affect an entire ecosystem? Explain how this change can affect the food chain of that species and the species with which it interacts, as well as how it will affect the entire food web. Describe how this change is either density-dependent or density-independent. Explain the affect an ecosystems carrying capacity have on a species, does this change affect growth of the population? What role do symbiotic relationships play in determining the effect of a species on its environment?