AP BIOLOGY

Detailed explanation-1: -Organisms in food chains are grouped into categories called trophic levels. Roughly speaking, these levels are divided into producers (first trophic level), consumers (second, third, and fourth trophic levels), and decomposers. Producers, also known as autotrophs, make their own food.

Detailed explanation-2: -It is occupied by a group of organisms that have a similar feeding mode. In an ecological pyramid, the various trophic levels are primary producers (at the base), consumers (primary, secondary, tertiary, etc.), and predators (apex). There are essentially two major types of organisms based on their feeding mode.

Detailed explanation-3: -Secondary consumers, at trophic level three, are carnivores and omnivores, which obtain at least part of their nutrients from the tissue of herbivores. This includes animals and carnivorous plants that feed on herbivorous insects (insectivores).

Detailed explanation-4: -In general, food energy in an ecosystem can be thought of as being structured like a pyramid, with energy moving upward, and each level in this energy pyramid corresponds to a trophic level (or feeding level) within the ecosystem.