The urinary bladder is useful because it:

The sense of smell uses photoreceptors.

Approximately how far does a red blood cell travel in the bloodstream before it is worn out and is removed?

Non-specific defense(s) include:

Birds excrete primarily ammonia because it is relatively non-toxic and requires little water to excrete.

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

The small intestine receives

The situation with major oceanic fishing areas is

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

The long process extending from the cell body of a nerve cell that carries impulses away from the cell body is the: