Chapter 06: Bacterial Growth, Nutrition, and Differentiation
MULTIPLE CHOICE
1. Given the incredibly fast division times of bacterial cells, which of the following could explain why
we are NOT surrounded by large mountains of bacterial cells?
a. Bacteria produce too much toxic iron.
b. Bacteria require a host cell to grow.
c. Bacteria are outcompeted by viruses.
d. Bacteria run out of nitrogen.
ANS: D DIF: Easy REF: 6.1
OBJ: 6.1a Compare heterotrophy, autotrophy, phototrophy, and chemotrophy.
MSC: Understanding
2. Which of the following is needed as an important enzyme cofactor for microbial growth?
a. Na+ c. sulfur
2+
b. Mg d. oxygen
ANS: B DIF: Moderate REF: 6.1
OBJ: 6.1a Compare heterotrophy, autotrophy, phototrophy, and chemotrophy.
MSC: Understanding
3. Examine the media recipes shown. What ingredients make Luria Bertani a complex medium as
opposed to a chemically defined minimal medium?
a. tryptone and NaCl
b. tryptone and yeast extract
c. NaCl and yeast extract
d. Luria Bertani is a chemically defined minimal medium.
ANS: B DIF: Moderate REF: 6.1
OBJ: 6.1a Compare heterotrophy, autotrophy, phototrophy, and chemotrophy.
MSC: Understanding
4. Which of the following could describe the relationship between the cyanobacterium Nostoc and E. coli
related to the carbon cycle?
a. Nostoc produces carbohydrates from lithotrophy, and E. coli breaks down the
, carbohydrates to generate CO2.
b. Nostoc produces carbohydrates from phototrophy, and E. coli breaks down the
carbohydrates to generate CO2.
c. Nostoc produces CO2 that E. coli turns into carbohydrates.
d. E. coli produces carbohydrates that Nostoc uses as energy to produce more carbohydrates.
ANS: B DIF: Moderate REF: 6.1
OBJ: 6.1b Describe the importance of the nitrogen and carbon cycles and the role of microbes in their
maintenance. MSC: Applying
5. Which of the following statements regarding examples of chemotrophy is FALSE?
a. Glucose is an oxidized compound that freely donates electrons to NAD, a more reduced
compound.
b. Glucose is a reduced compound that freely donates electrons to NAD, a more oxidized
compound.
c. NAD plays an important role in chemotrophic metabolism.
d. Glucose is an important chemotrophic carbon source.
ANS: A DIF: Moderate REF: 6.1
OBJ: 6.1b Describe the importance of the nitrogen and carbon cycles and the role of microbes in their
maintenance. MSC: Applying
6. What is the correct term for the chemical conversion shown below?
N2 ® NH4+
a. phototrophy c. denitrification
b. nitrification d. nitrogen fixation
ANS: D DIF: Moderate REF: 6.1
OBJ: 6.1b Describe the importance of the nitrogen and carbon cycles and the role of microbes in their
maintenance. MSC: Applying
7. What advantage does the plating method shown on the left panel below have over the plating method
shown in the right panel?
a. It can be used to isolate pure colonies.
b. It can be used to culture viable organisms.
c. It can be used to produce confluent growth.
d. It can be used to quantify the number of organisms in a given bacterial sample.
ANS: D DIF: Moderate REF: 6.2
MULTIPLE CHOICE
1. Given the incredibly fast division times of bacterial cells, which of the following could explain why
we are NOT surrounded by large mountains of bacterial cells?
a. Bacteria produce too much toxic iron.
b. Bacteria require a host cell to grow.
c. Bacteria are outcompeted by viruses.
d. Bacteria run out of nitrogen.
ANS: D DIF: Easy REF: 6.1
OBJ: 6.1a Compare heterotrophy, autotrophy, phototrophy, and chemotrophy.
MSC: Understanding
2. Which of the following is needed as an important enzyme cofactor for microbial growth?
a. Na+ c. sulfur
2+
b. Mg d. oxygen
ANS: B DIF: Moderate REF: 6.1
OBJ: 6.1a Compare heterotrophy, autotrophy, phototrophy, and chemotrophy.
MSC: Understanding
3. Examine the media recipes shown. What ingredients make Luria Bertani a complex medium as
opposed to a chemically defined minimal medium?
a. tryptone and NaCl
b. tryptone and yeast extract
c. NaCl and yeast extract
d. Luria Bertani is a chemically defined minimal medium.
ANS: B DIF: Moderate REF: 6.1
OBJ: 6.1a Compare heterotrophy, autotrophy, phototrophy, and chemotrophy.
MSC: Understanding
4. Which of the following could describe the relationship between the cyanobacterium Nostoc and E. coli
related to the carbon cycle?
a. Nostoc produces carbohydrates from lithotrophy, and E. coli breaks down the
, carbohydrates to generate CO2.
b. Nostoc produces carbohydrates from phototrophy, and E. coli breaks down the
carbohydrates to generate CO2.
c. Nostoc produces CO2 that E. coli turns into carbohydrates.
d. E. coli produces carbohydrates that Nostoc uses as energy to produce more carbohydrates.
ANS: B DIF: Moderate REF: 6.1
OBJ: 6.1b Describe the importance of the nitrogen and carbon cycles and the role of microbes in their
maintenance. MSC: Applying
5. Which of the following statements regarding examples of chemotrophy is FALSE?
a. Glucose is an oxidized compound that freely donates electrons to NAD, a more reduced
compound.
b. Glucose is a reduced compound that freely donates electrons to NAD, a more oxidized
compound.
c. NAD plays an important role in chemotrophic metabolism.
d. Glucose is an important chemotrophic carbon source.
ANS: A DIF: Moderate REF: 6.1
OBJ: 6.1b Describe the importance of the nitrogen and carbon cycles and the role of microbes in their
maintenance. MSC: Applying
6. What is the correct term for the chemical conversion shown below?
N2 ® NH4+
a. phototrophy c. denitrification
b. nitrification d. nitrogen fixation
ANS: D DIF: Moderate REF: 6.1
OBJ: 6.1b Describe the importance of the nitrogen and carbon cycles and the role of microbes in their
maintenance. MSC: Applying
7. What advantage does the plating method shown on the left panel below have over the plating method
shown in the right panel?
a. It can be used to isolate pure colonies.
b. It can be used to culture viable organisms.
c. It can be used to produce confluent growth.
d. It can be used to quantify the number of organisms in a given bacterial sample.
ANS: D DIF: Moderate REF: 6.2
