Practical examples show how viruses and bacteria are both beneficial and harmful to humans. Animations describe the structure of a virus, and explain how they reproduce and cause disease. Microscopic images illustrate different types and shapes of bacteria. The application of bacteria in our lives today is discussed. Other terminology includes: hosts, parasite, vaccine, fission, mutualism, cyanobacteria, saprophyte, pathogen, and antibiotics.

Originally released by Visual Learning, 2001. Streaming video file encoded with permission for digital streaming by Infobase on April 18, 2015.

Viruses (2:05); --Viral Diseases (1:29); -- Viruses and Their Structures (0:50); -- Virus Shapes and Classifications (0:42); -- Reproduction of Viruses (0:55); -- Human Viruses (1:06); -- Monerans (1:30); -- Bacterial Structure (0:52); -- Bacterial Shapes and Activities (2:33); -- Bacteria in Our Lives (1:53); -- Viruses and Monerans: Summing Up (1:08); -- Viruses and Monerans: Video Quiz (2:59); -- Credits: Viruses and Monerans (1:15); -- Bacteria (7:00);.