Answer:
1. Both food chains and food webs show the flow of energy in an ecosystem. However, food chains illustrate one path of energy, while food webs show multiple paths of energy and interactions among food chains.
2. About 90 percent of the energy at each trophic level is lost and not available to the next level. If the producer level has 100 units of energy, then 10 units of energy are available for the primary consumers.
3. Green plants. Just as 90 percent of the energy at each trophic level is lost, the amount of biomass is typically highest at the primary producer level and decreases in higher trophic levels.
4. Energy is lost to the environment in the form of heat.
Explanation:
Got this straight from Penn Foster, After I wrote the answers