AP BIOLOGY

Detailed explanation-1: -A producer is an organism that eats other organisms. A producer uses sunlight to create its own food through photosynthesis.

Detailed explanation-2: -A food chain describes how energy and nutrients move through an ecosystem. At the basic level there are plants that produce the energy, then it moves up to higher-level organisms like herbivores. After that when carnivores eat the herbivores, energy is transferred from one to the other.

Detailed explanation-3: -The cell theory holds true for multicellular and unicellular organisms.

Detailed explanation-4: -It follows that the carnivores (secondary consumers) that feed on herbivores and detritivores and those that eat other carnivores (tertiary consumers) have the lowest amount of energy available to them.