Portage Learning Microbiology Final Exam Practice
Questions | Most Tested Questions & 100% Correct
Answers | 2026 Update
1. Match the numbered terms to the descriptions that follow. Choose all
appropriate terms, but only appropriate terms. 32) An organism that relies on
photons to excite electrons within its membranes
phototroph
heterotroph
chemotroph
autotroph
2. If a researcher wants to study the internal structures of a bacterial cell in
detail, which type of microscopy would be most appropriate and why?
Electron Microscope, because it provides high-resolution images of
internal structures at the nanometer scale.
Phase Contrast Microscope, because it enhances contrast in
transparent specimens.
Bright Field Microscope, because it is the most commonly used
microscope.
Fluorescence Microscope, because it highlights specific proteins
within the cell.
3. Besides viewing flagella under the microscope, which two additional
methods can be used to observe bacterial cell motility?
Seeing live unstained microbes in a hanging drop preparation and
observing movement in motility agar
Motility agar only
, Hanging drop only
4. What type of enzyme is responsible for catalyzing the reaction A-B + H2O →
A-OH + B-H?
Transferase
Ligase
Oxidoreductase
Hydrolase
5. Describe the process of viral uncoating and its significance in the viral life
cycle.
Viral uncoating refers to the attachment of the virus to the host cell.
Viral uncoating is the stage where new viral particles are assembled.
Viral uncoating occurs when the virus exits the host cell.
Viral uncoating is the process where the viral capsid is removed,
allowing the viral genome to enter the host cell.
6. What is the primary characteristic that distinguishes lytic phages from
temperate phages?
Lytic phages only infect bacteria, while temperate phages can infect
both bacteria and eukaryotes.
Lytic phages replicate slowly, while temperate phages replicate
quickly.
Lytic phages are larger than temperate phages.
Lytic phages cause immediate cell lysis, while temperate phages
can integrate into the host genome.
7. What term is used to describe bacteria with a curved rod shape?
, Coccus
Bacillus
Spirillum
Vibrio
8. If a new bacterial species is identified with a thick peptidoglycan layer in its
cell wall, what result would you expect from a Gram stain procedure?
It would stain positive.
It would not stain at all.
It would stain purple only.
It would stain negative.
9. What does a scanning electron microscope (SEM) primarily image?
Internal structures of cells
DNA helix
Surface structures of specimens
Enzyme digestion of bacteria
10. If a microbiologist is attempting to isolate a pathogenic strain of
Staphylococcus aureus, which agar plate would be most appropriate to use
and why?
Trypticase Soy Agar, because it is a general-purpose medium.
LB Agar, because it supports the growth of a wide range of bacteria.
MacConkey Agar, because it isolates gram-negative bacteria.
Mannitol Salt Agar, because it selects for staphylococci and
differentiates mannitol fermenters.
Questions | Most Tested Questions & 100% Correct
Answers | 2026 Update
1. Match the numbered terms to the descriptions that follow. Choose all
appropriate terms, but only appropriate terms. 32) An organism that relies on
photons to excite electrons within its membranes
phototroph
heterotroph
chemotroph
autotroph
2. If a researcher wants to study the internal structures of a bacterial cell in
detail, which type of microscopy would be most appropriate and why?
Electron Microscope, because it provides high-resolution images of
internal structures at the nanometer scale.
Phase Contrast Microscope, because it enhances contrast in
transparent specimens.
Bright Field Microscope, because it is the most commonly used
microscope.
Fluorescence Microscope, because it highlights specific proteins
within the cell.
3. Besides viewing flagella under the microscope, which two additional
methods can be used to observe bacterial cell motility?
Seeing live unstained microbes in a hanging drop preparation and
observing movement in motility agar
Motility agar only
, Hanging drop only
4. What type of enzyme is responsible for catalyzing the reaction A-B + H2O →
A-OH + B-H?
Transferase
Ligase
Oxidoreductase
Hydrolase
5. Describe the process of viral uncoating and its significance in the viral life
cycle.
Viral uncoating refers to the attachment of the virus to the host cell.
Viral uncoating is the stage where new viral particles are assembled.
Viral uncoating occurs when the virus exits the host cell.
Viral uncoating is the process where the viral capsid is removed,
allowing the viral genome to enter the host cell.
6. What is the primary characteristic that distinguishes lytic phages from
temperate phages?
Lytic phages only infect bacteria, while temperate phages can infect
both bacteria and eukaryotes.
Lytic phages replicate slowly, while temperate phages replicate
quickly.
Lytic phages are larger than temperate phages.
Lytic phages cause immediate cell lysis, while temperate phages
can integrate into the host genome.
7. What term is used to describe bacteria with a curved rod shape?
, Coccus
Bacillus
Spirillum
Vibrio
8. If a new bacterial species is identified with a thick peptidoglycan layer in its
cell wall, what result would you expect from a Gram stain procedure?
It would stain positive.
It would not stain at all.
It would stain purple only.
It would stain negative.
9. What does a scanning electron microscope (SEM) primarily image?
Internal structures of cells
DNA helix
Surface structures of specimens
Enzyme digestion of bacteria
10. If a microbiologist is attempting to isolate a pathogenic strain of
Staphylococcus aureus, which agar plate would be most appropriate to use
and why?
Trypticase Soy Agar, because it is a general-purpose medium.
LB Agar, because it supports the growth of a wide range of bacteria.
MacConkey Agar, because it isolates gram-negative bacteria.
Mannitol Salt Agar, because it selects for staphylococci and
differentiates mannitol fermenters.
