AP BIOLOGY

Detailed explanation-1: -The base of the pyramid is composed of species called autotrophs, the primary producers of the ecosystem. All other organisms in the ecosystem are consumers called heterotrophs, which either directly or indirectly depend on the primary producers for food energy.

Detailed explanation-2: -At the bottom of the pyramid, you have producers. These are usually plants or other photosynthetic organisms, such as algae or photosynthetic bacteria. Producers are autotrophs, meaning they are self-feeding organisms that do so by making their own organic molecules.

Detailed explanation-3: -Plants, algae, and photosynthetic bacteria act as producers. Producers are autotrophs, or self-feeding organisms, that make their own organic molecules from carbon dioxide.

Detailed explanation-4: -Producers are at the bottom of the pyramid because they are able to transform the sun’s energy into a large amount of plant energy through the process of photosynthesis. Producers are the base of energy for most food chains and food webs. Animals that eat plants make up the next level.

Detailed explanation-5: -This is because, in order for the ecosystem to sustain itself, there must be more energy at lower trophic levels than there is at higher trophic levels. This allows organisms on the lower levels to not only maintain a stable population, but also to transfer energy up the pyramid.