Mbio Exam Questions With All Correct
Answers A+ Solution Guide
The appearance of gram-negative bacteria after addition of the decolorizing agent in the
Gram stain. - Answers -✔✔ Colorless
The purpose of a mordant in the Gram stain is - Answers -✔✔ to prevent the crystal
violet from leaving the cells (increase the affinity of the primary stain)
This microscope takes advantage of differences in the refractive indexes of cell
structures. - Answers -✔✔ Phase-contrast microscope
The best use of a negative stain is - Answers -✔✔ To determine cell size and To
determine cell shape
This microscope produces an image of a light cell against a dark background; internal
structures are not visible. - Answers -✔✔ Darkfield microscope
The media reports that "new" infections seem to appear on a regular basis. What is the
explanation for these infections? Are they "new"? - Answers -✔✔ This may be referring
to Emerging Infectious Diseases (EID). They may not be "new" at all, in fact. Factors
that contribute to EID are evolutionary changes in existing organisms, the spread of
known diseases to new geographic regions or populations by modern transportation,
human exposure to new, unusual infectious agents in areas that are undergoing
ecologic changes such as deforestation and construction, and changes in the
pathogen's ecology.
All of the following are products produced naturally by microorganisms except which
one?
A. alcohol
B. silk
C. lactic acid
D. acetone - Answers -✔✔ Silk
All of the following scientists performed experiments that proved the theory of
biogenesis except:
A. Virchow.
B. Pasteur.
Needham.
D. Redi. - Answers -✔✔ C. Needham.
The germ theory of disease was proven by: - Answers -✔✔ Koch.
,Which of the following is a scientific name? - Answers -✔✔ Legionella pneumophila
Pasteurization is used for all of the following purposes except which?
A. to remove all microorganisms from food
B. to remove spoilage microbes from food
C. to increase shelf-life of food
D. to remove pathogens from food - Answers -✔✔ to remove all microorganisms from
food
The cell theory states that are made up of cells. - Answers -✔✔ All living things
In Pasteur's swan neck flask experiment, the importance of the S-shaped curves in the
flasks was two-fold. The curves allowed entry of air, and yet excluded: - Answers -✔✔
Airborne bacteria.
All of the following are eukaryotes except:
A. Helminths.
B. Fungi.
C. Algae.
D. Bacteria.
E. Protozoa. - Answers -✔✔ Bacteria.
Using microbes to clean up pollutants is called: - Answers -✔✔ Bioremediation.
Increased human exposure to new and unusual infectious agents in areas that are
undergoing ecologic changes accounts for the: - Answers -✔✔ emergence of new
infectious disease.
All of the following are types of light microscopy except:
A. Atomic force
B. Brightfield
C. Fluorescence
D. Darkfield
E. Phase-contrast - Answers -✔✔ Atomic force
Which type of light microscopy is used to visualize stained specimens? - Answers -✔✔
Brightfield.
In the Gram stain, crystal violet is the ____________________. - Answers -✔✔ primary
stain.
In the Gram stain, if the decolorizing step is deleted, gram-negative cells will appear
____at the completion of the staining procedure. - Answers -✔✔ purple
, In a negative staining procedure, the bacterial cells would be ____________________.
- Answers -✔✔ unstained in a colored background.
Which of the following organelles represents the power house of the cell? - Answers -
✔✔ mitochondria
Which of the following would most likely not gram stain? - Answers -✔✔ Mycobacterium
Which type of bacteria have a structurally and chemically more complex cell wall? -
Answers -✔✔ gram-negative bacteria.
Bacterial endospores function in - Answers -✔✔ survival
Endospores represent a challenge to the fields of industrial and medical microbiology
because - Answers -✔✔ A. they are resistant to harsh environments
B. spore forming organisms are often dangerous pathogens.
C. spores are stable for hundreds if not thousands of years
An HIV positive patient was experiencing a chronic cough and low grade fever. The
patient knew he had been exposed to walking pneumonia (Mycoplasma). His physician
should not order a gram stain because - Answers -✔✔ Mycoplasma do not have cell
walls
Why does high salt act as a preservative for food? - Answers -✔✔ it causes bacteria to
lose water, causing plasmolysis
A slime layer or capsule is made of a material known as - Answers -✔✔ glycocalyx
Spherical shaped bacteria that divide and remain attached in chainlike patterns are
called: - Answers -✔✔ streptococci.
Which of the following organisms would be resistant to cooking at high temperatures? -
Answers -✔✔ Clostridium
You have discovered an antibiotic that works by interfering with cell wall synthesis. It
could therefore have an effect on all of the following EXCEPT - Answers -✔✔
Mycoplasma
All of the following are characteristic of a gram positive bacterial cell EXCEPT - Answers
-✔✔ contains a periplasmic space
All of the following are characteristic of a gram positive bacterial cell - Answers -✔✔ B.
contains peptidoglycan
C. contains teichoic acid
Answers A+ Solution Guide
The appearance of gram-negative bacteria after addition of the decolorizing agent in the
Gram stain. - Answers -✔✔ Colorless
The purpose of a mordant in the Gram stain is - Answers -✔✔ to prevent the crystal
violet from leaving the cells (increase the affinity of the primary stain)
This microscope takes advantage of differences in the refractive indexes of cell
structures. - Answers -✔✔ Phase-contrast microscope
The best use of a negative stain is - Answers -✔✔ To determine cell size and To
determine cell shape
This microscope produces an image of a light cell against a dark background; internal
structures are not visible. - Answers -✔✔ Darkfield microscope
The media reports that "new" infections seem to appear on a regular basis. What is the
explanation for these infections? Are they "new"? - Answers -✔✔ This may be referring
to Emerging Infectious Diseases (EID). They may not be "new" at all, in fact. Factors
that contribute to EID are evolutionary changes in existing organisms, the spread of
known diseases to new geographic regions or populations by modern transportation,
human exposure to new, unusual infectious agents in areas that are undergoing
ecologic changes such as deforestation and construction, and changes in the
pathogen's ecology.
All of the following are products produced naturally by microorganisms except which
one?
A. alcohol
B. silk
C. lactic acid
D. acetone - Answers -✔✔ Silk
All of the following scientists performed experiments that proved the theory of
biogenesis except:
A. Virchow.
B. Pasteur.
Needham.
D. Redi. - Answers -✔✔ C. Needham.
The germ theory of disease was proven by: - Answers -✔✔ Koch.
,Which of the following is a scientific name? - Answers -✔✔ Legionella pneumophila
Pasteurization is used for all of the following purposes except which?
A. to remove all microorganisms from food
B. to remove spoilage microbes from food
C. to increase shelf-life of food
D. to remove pathogens from food - Answers -✔✔ to remove all microorganisms from
food
The cell theory states that are made up of cells. - Answers -✔✔ All living things
In Pasteur's swan neck flask experiment, the importance of the S-shaped curves in the
flasks was two-fold. The curves allowed entry of air, and yet excluded: - Answers -✔✔
Airborne bacteria.
All of the following are eukaryotes except:
A. Helminths.
B. Fungi.
C. Algae.
D. Bacteria.
E. Protozoa. - Answers -✔✔ Bacteria.
Using microbes to clean up pollutants is called: - Answers -✔✔ Bioremediation.
Increased human exposure to new and unusual infectious agents in areas that are
undergoing ecologic changes accounts for the: - Answers -✔✔ emergence of new
infectious disease.
All of the following are types of light microscopy except:
A. Atomic force
B. Brightfield
C. Fluorescence
D. Darkfield
E. Phase-contrast - Answers -✔✔ Atomic force
Which type of light microscopy is used to visualize stained specimens? - Answers -✔✔
Brightfield.
In the Gram stain, crystal violet is the ____________________. - Answers -✔✔ primary
stain.
In the Gram stain, if the decolorizing step is deleted, gram-negative cells will appear
____at the completion of the staining procedure. - Answers -✔✔ purple
, In a negative staining procedure, the bacterial cells would be ____________________.
- Answers -✔✔ unstained in a colored background.
Which of the following organelles represents the power house of the cell? - Answers -
✔✔ mitochondria
Which of the following would most likely not gram stain? - Answers -✔✔ Mycobacterium
Which type of bacteria have a structurally and chemically more complex cell wall? -
Answers -✔✔ gram-negative bacteria.
Bacterial endospores function in - Answers -✔✔ survival
Endospores represent a challenge to the fields of industrial and medical microbiology
because - Answers -✔✔ A. they are resistant to harsh environments
B. spore forming organisms are often dangerous pathogens.
C. spores are stable for hundreds if not thousands of years
An HIV positive patient was experiencing a chronic cough and low grade fever. The
patient knew he had been exposed to walking pneumonia (Mycoplasma). His physician
should not order a gram stain because - Answers -✔✔ Mycoplasma do not have cell
walls
Why does high salt act as a preservative for food? - Answers -✔✔ it causes bacteria to
lose water, causing plasmolysis
A slime layer or capsule is made of a material known as - Answers -✔✔ glycocalyx
Spherical shaped bacteria that divide and remain attached in chainlike patterns are
called: - Answers -✔✔ streptococci.
Which of the following organisms would be resistant to cooking at high temperatures? -
Answers -✔✔ Clostridium
You have discovered an antibiotic that works by interfering with cell wall synthesis. It
could therefore have an effect on all of the following EXCEPT - Answers -✔✔
Mycoplasma
All of the following are characteristic of a gram positive bacterial cell EXCEPT - Answers
-✔✔ contains a periplasmic space
All of the following are characteristic of a gram positive bacterial cell - Answers -✔✔ B.
contains peptidoglycan
C. contains teichoic acid
