Work in groups on these problems. You should try to answer the questions without referring to your textbook. If you get stuck, try asking another group for help.
1. Which UV exposure time/condition had the least amount of bacterial colonies? Why? (1)
2. Can UV light destroy bacterial spores? (0.5)
3. How did wrapping the tubes prior to autoclaving them affect the ability of the autoclave machine to sterilize? (0.5)
4. What germicide was the best at killing E. coli? S. epidermidis? (1)
5. Is there a difference between the germicides that work against E. coli vs. S. epidermidis? Why? (1)
6. What do the control tubes with the beads control for? Which is the positive and which is the negative control? (1)