Explain how entropy relates to the amount of energy that is available in the different trophic levels of a food chain.

Entropy is defined as the increase in disorder in a system. This occurs in the food chain because as animals eat food, they supply less energy to the next level of the food chain. What does this mean? Think of a rabbit. The rabbit eats almost all day, everyday. The energy in the grass is in an ordered state but becomes disordered as it goes though the rabbit. This is because the rabbit does things like cellular respiration, and gives off heat (this is wasted energy -- disorder). So out of the total amount of energy that flows through the rabbit only about 10% of this energy goes on to a fox that eats a rabbit due to all of this wasted energy. Cheers!

the area between the graph and the t axis

it doesn't. it was imagined up in the middle ages.