MIC 205 FINAL UPDATED ACTUAL QUESTIONS AND CORRECT ANSWERS

MIC 205 FINAL UPDATED ACTUAL QUESTIONS AND
CORRECT ANSWERS

Question:
1. Which of the following do not belong to any of three domains of cellular life?
Answer:
Viruses

Question:
2. Which of the following statements is correct?
Answer:
Not all bacteria are microbes.

Question:
3. Where did the first microbe likely appear on earth?
Answer:
3.7 billion years or earlier

Question:
4. Which name of the following is in a scientifically correct format for a bacterium?
Answer:
Caulobacter crescentus

Question:
5. True or false? Most antibiotics come from nature (they are produced mostly by microbes and plants, and
were discovered by scientists)
Answer:
True

Question:
6. What is the correct order of reagents in the Gram stain?
Answer:
Crystal violet, iodine, ethanol, safranin

Question:
7. The first person who invented light microscopy to visualize individual microbes was:
Answer:
Antonie van Leeuwenhoek

Question:
8. True of false? The maximum resolution of fluorescence microscopy could NEVER become better than
0.2 micrometers by any means (please considering 2014 Nobel Prize in Chemistry).
Answer:
False

,Question:
9. Why does electron microscopy (EM) have much higher resolution than light microscopy (the main
reason)?
Answer:
Electrons have much a shorter wavelength than visible light.

Question:
10. Who proposed endosymbiosis hypothesis to explain the origin of mitochondria and chloroplasts
Answer:
Lynn Margulis

Question:
11. What is a concentrated gel-like matrix in the space between the inner cytoplasmic membrane and the
bacterial outer membrane?
Answer:
Periplasm

Question:
12. Gram-negative cells have endotoxin which elicits strong immune responses in animals. What is this
endotoxin in Gram-negative bacteria?
Answer:
Lipopolysaccharide

Question:
13. Which of the following is false about the outer membrane in Gram-negative bacteria?
Answer:
It is composed of a phospholipid bilayer.

Question:
14. Which of the following statements is true?
Answer:
Gram-positive cells do not have an outer membrane.

Question:
15. How many E. coli cells are present after 2 hours if one cell starts growing with a doubling time of 30
minutes?
Answer:
16

Question:
16. How many E. coli cells are present after 12 hours if one cell starts growing with a doubling time of 30
minutes?
Answer:
2²■ = 16.8 million

, Question:
17. Which bacterium grows faster, A with a specific growth rate of 0.5 h■¹ or B with a specific growth rate
of 0.3 h■¹?
Answer:
A

Question:
18. What type of organism is Acidithiobacillus thiooxidans?
Answer:
Chemoautotroph

Question:
19. What are the four growth phases for microbes when cultured in a shake flask?
Answer:
Lag Log/Exponential ’ Sta- ’ tionary ’ Death

Question:
20. What is negatively correlated to the number of bacterial cells in liquid culture?
Answer:
The concentration of autoinducers.

Question:
21. What components are commonly found in the extracellular polymeric substance (EPS) of biofilms?
Answer:
Polysaccharides, DNA, pili, and other protein components.

Question:
22. True or False? Biofilms are rarely found in native environments.
Answer:
False

Question:
23. True or False? Certain different microbial species can 'communicate' with each other through quorum
sensing mechanisms.
Answer:
True

Question:
24. True or False? Bacteria in biofilm are usually more resistant to antibiotics than those in planktonic
state.
Answer:
True

Question:
25. Which of the following statements is correct? (image)