Bacteria and viruses are microorganisms that can cause disease in humans. Bacteria are single-celled organisms that can infect different parts of the body and cause illnesses like strep throat, pneumonia, and meningitis. Viruses are even smaller than bacteria and can only replicate inside of living cells; they are responsible for diseases such as the common cold, influenza, hepatitis, herpes, and HIV/AIDS.

1. DISEASE CAUSING
MICROORGANISMS