A tool used to classify organisms based on physical characteristics.

The sequence of energy transfer in the form of food from organism to organism.

An area where living and nonliving things interact.

All the organisms of the same species that live in the same place at the same time.

 The place in which an animal or plant naturally lives.

A system in which members of a population interact with other populations.

The group of interacting food chains in an ecosystem.

The function or role that an organism performs in the food web of that community.