Learn about how ecology is simply the study of how and why organisms interact with their environments.

This website describes trophic levels, transfer of energy between trophic levels, pyramids of ecology, and nutrient cycles within the environment.

Abiotic factors vary in the environment and determining the types and numbers of organisms that exist in that environment. Factors which determine the types and numbers of organisms of a species in an ecosystem are called limiting...

Different groups of prokaryotes. Evolutionary relationships of bacteria and archaea. Extremophiles.