What general feature defines an organism as a microbe?

A) generally require a microscope to be seen
B) multicellular
C) heterotrophic
D) sexual reproduction
E) use aerobic respiration for metabolism

Aerobic Respiration

A process of producing cellular energy involving oxygen; cells break down food into water and carbon dioxide, releasing energy.

Microbe

A microscopic organism, such as bacteria, viruses, fungi, and protozoa, which can be beneficial or harmful.