Create a of the Chapter 6, adding information from the videos when appropriate
2) Answer the Critical Thinking Questions
Cowan Microbiology Fundamentals, 4/e, Critical Thinking Questions
Chapter 6
1. a. Compare and contrast passive and active forms of transport, using examples of what is being transported and the requirements for each.
b. How are phagocytosis and pinocytosis similar? How are they different?
2. Compare the effects of isotonic, hypotonic, and hypertonic solutions on an amoeba and on a bacterial cell. If a cell lives in a hypotonic environment, what will occur if it is placed in a hypertonic one?
3. How can you explain the observation that unopened milk will spoil even while refrigerated?
4. a. If an egg salad sandwich sitting in a warm car for 4 hours develops 40,960 bacterial cells, how many more cells would result in just one more generation?
b. What would the cell count be after 4 hours if the initialbacterial dose was 100 cells? [Hint: cell number doubles every 20 minutes]
c. What do your answers tell you about using clean techniques in food preparation
and storage (other than esthetic considerations)?
5. Consider figure 6.6, and note that the medium at the bottom of tube 2 is clear
containing no growth, whereas tube 3 contains growththroughout. Explain what is probably causing this difference. [Hint: Look at oxygen as an environmental factor influencing bacterial growth]
Leave a Reply