The central core of the brain consists of a series of structures including the which is responsible for producing and maintaining essential body functions (such as heartbeat, breathing, and blood pressure).

Select the true statements about eubacteria. most live as decomposers and heterotrophs. most only thrive in a narrow range of environments. certain eubacteria are responsible for food poisoning. eubacteria thrive in extreme environments.

Explain how paleontologists use trilobite fossils as index fossils for various geologic time periods.

Which of the following describes a bathypelagic zone