1. Define and differentiate between density- dependent and density-independent limiting factors Explain why ecosystems require a constant input of energy from an external source. Name two specific sources where this energy can come from. Differentiate between net primary and gross primary production. With respect to cycling of matter, explain the relationship between photosynthesis and respiration

2. Describe what happens to the amount of energy available to each successive trophic level in a food chain. Explain why this is the case. Compost heaps can generate a great deal of heat. Explain where this heat is coming from and what natural law guides this process. In certain conditions, detritus will build up in an environment where few or no decomposers can exist. Describe the consequences of this lack of decomposer activity to the energy flow in the ecosystem. Name three examples of materials that have resulted from a lack of decomposer activity on detritus material

3. Describe three processes that release carbon into the atmosphere. Choose one of these processes and explain how humans altered this process. Explain through an example, how a positive feedback mechanism can accelerate any global biological process. Justify a scientific claim that free energy is required for living systems to maintain organization, to grow or to reproduce, but that multiple strategies exist in different living systems. Represent graphically the exchange of nitrogen between an organism and its environment.

4. Name a specific invasive species and describe how this species altered its new environment. Name one density-dependent limiting factor and describe how it alters the growth of a particular population. Describe what kind of data you would collect to determine the effect of eutrophication on the oxygen concentration of a lake. Describe how a community would respond to a destruction due to a volcanic eruption. Name two environmental conditions that can trigger migration and two ways the organisms would orient themselves.