Answers to End-of-Chapter Questions
CHAPTER 9 Controlling Microbial Growth in the Environment
Multiple Choice
Short Answer
1. Bacterial endospores can survive chemical disinfectants and extremes of environmental
2. Three tests phenol coefficient, use-dilution, and disk-diffusion measure effectiveness
of a disinfectant against one or a few species, whereas the in-use test determines
Microbiology with Diseases by Body System, 5e
13. Soap molecules are hydrophobic on one end and hydrophilic on the other. They are good
Visualize It!
Critical Thinking
1. Cooking the sandwich would have killed many microbes and driven off water,
5. Fishers can pack fish in salt or freeze fish promptly and thoroughly after capture or
cleaning. The smoking should have been done under proper conditions. Packers can
Answers to End-of-Chapter Questions
8. The widespread use of antiseptics and disinfectants creates selective pressure on
dissolved in water.
10. Take a sample from the clear tube and dilute it into fresh medium lacking the chemical,
13. Liquid water is required for metabolites to be suspended and thus transportable to various
15. Ironing mail with a household iron is not an effective way to disinfect mail contaminated
with endospores because the heat generated by the iron is insufficient to destroy the
Concept Mapping
1. Boiling water
Microbiology with Diseases by Body System, 5e
2. Thermoduric microorganisms
3. Vegetative Bacterial cells