Answer:
The relationship between tropic levels and energy is that tropic levels contain a certain amount of energy depending of which level they are, the lowest tropic level will have the highest amount of energy, whilst the highest tropic level will have the lowest amount of energy.
The role of the organisms in the first tropic level is to produce food since they are autotrophs, these organisms do not rely on others for food. the organisms in the second level will control the amount of primary producers and will serve as food for tertiary consumers. The role of the organisms in the third level is to get food from secondary consumers so they don't overpopulate and affect primary consumers more than they have to.
Energy availability changes at each level because of the 10 percent rule. As you go higher, only 10 percent of the energy can actually be consumed by the consumer in the next level.