Straighterline Microbiology Midterm
Exam Review With 100% Correct And
Verified Answers 2025-2026
1. Agar is a complex polysaccharide that comes from a/an ___________.
a. green plant
b. fungus
c. bacterium
d. algae
e. marine invertebrate - Correct Answer>-d. algae
2. Using microbes to detoxify a site contaminated with heavy metals is an example of
_________.
a. biotechnology
b. bioremediation
c. decomposition
d. immunology
e. epidemiology - Correct Answer>-b. bioremediation
3. The three physical forms of laboratory media are _____________.
a. solid, liquid, and gas
b. solid, semisolid, and liquid
c. a streak plate, a pour plate, and a broth
d. reducing, transport, and enumeration - Correct Answer>-b. solid, semisolid, and
liquid
4. Which of the following is a traditional human use of microorganisms?
a. baking
b. treating water and sewage
c. mass-producing antibiotics
d. cleaning up oil spills - Correct Answer>-a. baking bread
5. Which of the following represents a synthesis reaction?
a. AB --> A + B
b. A + B --> AB
c. AB + XY --> AY +XB
d. AB + XY <--> AY + XB - Correct Answer>-b. A + B --> AB
6. Basic dyes are
, a. attracted to the acidic surface of bacterial cells
b. anionic
c. used in negative staining
d. repelled by cells
e. dyes such as India ink and nigrosin - Correct Answer>-a. attracted to the acidic
surface of bacterial cells
7. The type of microscopy in which you would observe brightly illuminated specimens
against a black background is __________
a. confocal
b. dark-field
c. phase-contrast
d. fluorescence
e. electron - Correct Answer>-b. dark-field
8. A reducing medium is used to culture _________ organisms.
a. fastidious
b. aerobic
c. anaerobic
d. pathogenic - Correct Answer>-c. anaerobic
9. In the cell cytoplasm, molecules of ATP are a ________
a. solute
b. solvent - Correct Answer>-a. solute
10. A diagram of the three domains (Bacteria, Archaea, Eukarya) proceeding from the Last
Universal Common Ancestor would show Archaea
a. as the original cells from which the others derived
b. branching off the domain Eukarya
c. branching off of the domain Bacteria - Correct Answer>-b. branching off the
domain Eukarya
11. In the experiments constructed by Pasteur to disprove spontaneous generation, swan-
necked flasks were used. Why was this shape of flask used in this experiment.
a. the glass neck needed to be open to the air, yet constructed so that bacteria
would settle in the lowest part of the flask
b. these flask shapes were the easiest and cheapest to produce
, Straighterline Microbiology Midterm
Exam Review With 100% Correct And
Verified Answers 2025-2026
c. the shape of the glass neck allowed the bacteria into the flask and then into the
media, but air could not enter
d. Because the glass necks were stretched out, the heat used to sterilize the
medium inside of the flask could not kill the bacteria in the neck - Correct
Answer>-a. the glass neck needed to be open to the air, yet constructed so that
bacteria would settle in the lowest part of the flask
12. Atoms that gain or lose electrons become charged particles called____________
a. cations
b. anions
c. ions
d. isotopes - Correct Answer>-c. ions
13. The three cell types discussed, eukaryotes, archaea, and bacteria, all derived from
a. the last universal common ancestor
b. photosynthetic bacteria
c. archaea
14. cells
15. d. cells with a true necleaus - Correct Answer>-a. the last universal common ancestor
16. A nutrient medium that has all of its chemical components identified and their precises
contractions known and reproducable is termed_________
a. complex
b. reducing
c. enriched
d. defined - Correct Answer>-d. defined
17. What part of a phosphate comprises the hydrophobic tail?
a. fatty acids
18. b.glycerol
19. c. phosphates
20. d. alcohol
21. e. hydroxyl - Correct Answer>-a. fatty acids
22. Which of the following is not a pyrimidine?
Exam Review With 100% Correct And
Verified Answers 2025-2026
1. Agar is a complex polysaccharide that comes from a/an ___________.
a. green plant
b. fungus
c. bacterium
d. algae
e. marine invertebrate - Correct Answer>-d. algae
2. Using microbes to detoxify a site contaminated with heavy metals is an example of
_________.
a. biotechnology
b. bioremediation
c. decomposition
d. immunology
e. epidemiology - Correct Answer>-b. bioremediation
3. The three physical forms of laboratory media are _____________.
a. solid, liquid, and gas
b. solid, semisolid, and liquid
c. a streak plate, a pour plate, and a broth
d. reducing, transport, and enumeration - Correct Answer>-b. solid, semisolid, and
liquid
4. Which of the following is a traditional human use of microorganisms?
a. baking
b. treating water and sewage
c. mass-producing antibiotics
d. cleaning up oil spills - Correct Answer>-a. baking bread
5. Which of the following represents a synthesis reaction?
a. AB --> A + B
b. A + B --> AB
c. AB + XY --> AY +XB
d. AB + XY <--> AY + XB - Correct Answer>-b. A + B --> AB
6. Basic dyes are
, a. attracted to the acidic surface of bacterial cells
b. anionic
c. used in negative staining
d. repelled by cells
e. dyes such as India ink and nigrosin - Correct Answer>-a. attracted to the acidic
surface of bacterial cells
7. The type of microscopy in which you would observe brightly illuminated specimens
against a black background is __________
a. confocal
b. dark-field
c. phase-contrast
d. fluorescence
e. electron - Correct Answer>-b. dark-field
8. A reducing medium is used to culture _________ organisms.
a. fastidious
b. aerobic
c. anaerobic
d. pathogenic - Correct Answer>-c. anaerobic
9. In the cell cytoplasm, molecules of ATP are a ________
a. solute
b. solvent - Correct Answer>-a. solute
10. A diagram of the three domains (Bacteria, Archaea, Eukarya) proceeding from the Last
Universal Common Ancestor would show Archaea
a. as the original cells from which the others derived
b. branching off the domain Eukarya
c. branching off of the domain Bacteria - Correct Answer>-b. branching off the
domain Eukarya
11. In the experiments constructed by Pasteur to disprove spontaneous generation, swan-
necked flasks were used. Why was this shape of flask used in this experiment.
a. the glass neck needed to be open to the air, yet constructed so that bacteria
would settle in the lowest part of the flask
b. these flask shapes were the easiest and cheapest to produce
, Straighterline Microbiology Midterm
Exam Review With 100% Correct And
Verified Answers 2025-2026
c. the shape of the glass neck allowed the bacteria into the flask and then into the
media, but air could not enter
d. Because the glass necks were stretched out, the heat used to sterilize the
medium inside of the flask could not kill the bacteria in the neck - Correct
Answer>-a. the glass neck needed to be open to the air, yet constructed so that
bacteria would settle in the lowest part of the flask
12. Atoms that gain or lose electrons become charged particles called____________
a. cations
b. anions
c. ions
d. isotopes - Correct Answer>-c. ions
13. The three cell types discussed, eukaryotes, archaea, and bacteria, all derived from
a. the last universal common ancestor
b. photosynthetic bacteria
c. archaea
14. cells
15. d. cells with a true necleaus - Correct Answer>-a. the last universal common ancestor
16. A nutrient medium that has all of its chemical components identified and their precises
contractions known and reproducable is termed_________
a. complex
b. reducing
c. enriched
d. defined - Correct Answer>-d. defined
17. What part of a phosphate comprises the hydrophobic tail?
a. fatty acids
18. b.glycerol
19. c. phosphates
20. d. alcohol
21. e. hydroxyl - Correct Answer>-a. fatty acids
22. Which of the following is not a pyrimidine?
