Chapter 20
Viruses & Prokaryotes

Chapter Resources

Infectious Disease - Research and Piublic Health News
(@ the University of Minnesota)

All about Bacteriophage

Dmitri Ivanovsky
(Believe it or not, he's got a stamp and a Facebook page!)

Prokaryotes, Eukaryotes, & Viruses
A tutorial from the University of Arizona

Prokaryotic Cells



The Science of Biology
Q: What role does science play in the study of life?

Think about it - Imagine that you have been presented with a great puzzle. Farmers have begun to lose their valuable tobacco crop to a plant disease that first appears as a yellowing of the leaves. Eventually the leaves wither and die, killing the plant. You look for a germ that might be causing the disease, but none can be seen, even under the most powerful light microscope. Eventually, you show that a tiny disease-causing agent has infected the leaves, and you decide to name it after the Latin word for evil: "virus."

Key Questions Include:

How do viruses reproduce?
What happens after a virus infects a cell?
How are prokaryotes classified?
How do prokaryotes vary in structure and function?
What roles do prokaryotes play in the living world?
How do bacteria cause disease?
How do viruses cause disease?
Why are emerging diseases particularly threatening to human health?

Active Art: Virus Reproduction
SciLinks: Bacteria

A Student's Guide to Bacteria
(Thanks to Alexa from Colorado Springs!)

The Mad Cows

In 1986, something strange began to happen to cattle in Great Britain. Without warning, the animals began acting strangely, losing control of their movements, staggering and stumbling. The disease affected more than 30,000 cattle in 1991. What was going on? Read the clues, and then solve the mystery.

Click Here for the complete Chapter Mystery

Should more vaccinations be required? Vaccination has become a controversial issue. What does the science say?