The tubular structure that moves food by peristalsis from the mouth to the stomach is the __.

A community contains both the biotic and abiotic components of the local environment, all the living organisms along with their physical environment.

The zone of a lake closest to shore that contains rooted plants.

The site of gas exchange in the lungs is these thin walled sacs with a rich blood supply.

The main nitrogenous waste excreted by mammals is:

Population size levels off at the ____ of an environment.

Which kind of blood cell is involved in clotting?

Structure(s) that amplify sound waves in the middle ear.

Which kind of T cell is most important in the removal of cancer cells or infected host cells?

Area where a large river flows into an ocean.