Answer:

Bacteria.

Explanation:

These one-cell organisms are responsible for illnesses such as strep throat, urinary tract infections and tuberculosis. Viruses. Even smaller than bacteria, viruses cause a multitude of diseases ranging from the common cold to AIDS.

Answer:

The Correct Answer is: Bacteria

Explanation:

Because Bacteria is a one-cell organisms responsible for illnesses such as strep throat, urinary tract infections and tuberculosis. Viruses. Even smaller than bacteria, viruses cause a multitude of diseases ranging from the common cold to AIDS.