WGU OA D311: Microbiology Exam 2025
Questions and Answers
What is the significance of microorganisms containing a thick coat of peptldogiywn within the
cell wall? - ANS Microorganisms containing a thick coat of peptidoglycan within the cell wall
are typically classified as gram-positive bacteria.
Why are viruses considered aceilular? - ANS They cannot reproduce without a host.
What is the defining characteristic of eukaryotes? - ANS They have a nucleus.
Which microorganism can cause vaginal yeast Infections and oral thrush? - ANS Fungi
Why can It be difficult to determine the etiologic agent of a disease? - ANS Some signs and
symptoms can be caused by many different etiologic agents.
What kind of staining technique Is the acid-fast stain? - ANS
A doctor prescribed antibiotics for a patient complaining of runny nose. fever. and aches and
pains. Which type of infection did the doctor suspect? - ANS The doctor likely suspected a
viral infection because antibiotics are not effective against viral infections.
A healthcare professional is treating a patient who developed a yeast infection after taking
antibiotics. What type of medication should be prescribed to this patient? - ANS Antifungals
Pg. 1 Copyright © 2025 Jasonmcconell. ALL RIGHTS RESERVED.
, Which structure promotes motility in Proteus. Shigelia. and Salmonella species. all of which can
cause serious disease in humans? - ANS Presence of flagella
Which bacterial virulence factor allows a strain to resist phagocytosis, increasing the organism's
virulence? - ANS Capsule production
Why is treating Haemophilus influenzae difficult? - ANS The capsule is antiphagocytic.
How do pili aid pathogens in causing disease? - ANS They cause pathogens to adhere to host
cells.
Which virulence factor allows pathogens to penetrate the dermis and invade the body? -
ANS Bacterial enzymes
A bacterium from a deep-sea hydrothermal vent has been cultured. Which staining technique
should be used to begin the process of species identification? - ANS Gram staining
What does the presence of a clear area around a cell stained with India ink indicate about the
cell? - ANS The cell has a capsule.
How do basic stains work? - ANS The positively charged stain is attracted to the negatively
charged portion of the cell.
Which staining technique is used to distinguish bacteria based on their ability to produce
structures that can survive extreme heat stress? - ANS Endospore stain
Which aspect of a staining protocol enables dye to penetrate an endospore? - ANS Heat
Pg. 2 Copyright © 2025 Jasonmcconell. ALL RIGHTS RESERVED.
Questions and Answers
What is the significance of microorganisms containing a thick coat of peptldogiywn within the
cell wall? - ANS Microorganisms containing a thick coat of peptidoglycan within the cell wall
are typically classified as gram-positive bacteria.
Why are viruses considered aceilular? - ANS They cannot reproduce without a host.
What is the defining characteristic of eukaryotes? - ANS They have a nucleus.
Which microorganism can cause vaginal yeast Infections and oral thrush? - ANS Fungi
Why can It be difficult to determine the etiologic agent of a disease? - ANS Some signs and
symptoms can be caused by many different etiologic agents.
What kind of staining technique Is the acid-fast stain? - ANS
A doctor prescribed antibiotics for a patient complaining of runny nose. fever. and aches and
pains. Which type of infection did the doctor suspect? - ANS The doctor likely suspected a
viral infection because antibiotics are not effective against viral infections.
A healthcare professional is treating a patient who developed a yeast infection after taking
antibiotics. What type of medication should be prescribed to this patient? - ANS Antifungals
Pg. 1 Copyright © 2025 Jasonmcconell. ALL RIGHTS RESERVED.
, Which structure promotes motility in Proteus. Shigelia. and Salmonella species. all of which can
cause serious disease in humans? - ANS Presence of flagella
Which bacterial virulence factor allows a strain to resist phagocytosis, increasing the organism's
virulence? - ANS Capsule production
Why is treating Haemophilus influenzae difficult? - ANS The capsule is antiphagocytic.
How do pili aid pathogens in causing disease? - ANS They cause pathogens to adhere to host
cells.
Which virulence factor allows pathogens to penetrate the dermis and invade the body? -
ANS Bacterial enzymes
A bacterium from a deep-sea hydrothermal vent has been cultured. Which staining technique
should be used to begin the process of species identification? - ANS Gram staining
What does the presence of a clear area around a cell stained with India ink indicate about the
cell? - ANS The cell has a capsule.
How do basic stains work? - ANS The positively charged stain is attracted to the negatively
charged portion of the cell.
Which staining technique is used to distinguish bacteria based on their ability to produce
structures that can survive extreme heat stress? - ANS Endospore stain
Which aspect of a staining protocol enables dye to penetrate an endospore? - ANS Heat
Pg. 2 Copyright © 2025 Jasonmcconell. ALL RIGHTS RESERVED.
