MICR 2420: Midterm Test Questions
with Solved Solutions 2025-2026
Updated.
Which of the following family of viruses have DNA genomes - Answer Hepadnaviridae
The single stranded negative strand RNA of a virus - Answer must be converted to positive
strand RNA in order to be translated into proteins
The distinction between a prion and a virus is that - Answer A prion is a single protein
molecule whereas a virus may contain many copies of one or several proteins
The Pasteur Swan Neck flask experiment shows that - Answer microorganisms are present in
air and they can contaminate a nutrient rich broth
The Koch's postulate is used to - Answer determine which organism causes a particular
infectious disease
Which type of microscopy can be used to study the interior structures of a live bacteria? -
Answer phase contrast
Which of the following techniques can be used to observe ribosomes within a cell - Answer
Transmission electron microscopy
Which of the following microorganisms belong to the domain Archea - Answer Methanogens
Which of the following structures below can be found in the cell wall of a Gram positive
bacteria? - Answer teichoic acid
An absent-minded laboratory technician forgot the ethanol wash step in his gram negative
staining procedure. As a result; - Answer Both Gram positive bacteria and Gram negative
bacteria are stained purple
Which of the following contains 80S ribosomes - Answer ribosomes attached to the
membrane of rough endoplasmic reticulum
Which of the following contain proteins involved in the electron transport chain? - Answer
bacterial cytoplasmic membrane
, Which of the following explains the mechanism of chemotaxis in bacteria? - Answer If a
bacterium senses that it is moving towards a nutrient source, its flagella will rotate anti-
clockwise more frequently than clockwise
How does facilitated diffusion resemble active transport - Answer membrane proteins are
requires in both processes
Which of the following best describes what happens to a bacterium when it is placed in a
solution containing a high concentration of sodium chloride - Answer water will move out of
cell by osmosis
__________ is the product of ancestral engulfment of a prokaryotic cell according to the theory
of endosymbiosis - Answer chloroplast
Which of the following statements regarding microorganisms from the domain Archea is false? -
Answer some members can cause disease in humans
Which of the following is a characteristic of fungi - Answer they are heterotrophs
You grew two different bacteria, x and y, in test tube cultures without shaking. After several days
you made the following observations - Answer x is an aerobe while y is a facultative
anaerobe
The conversion of nitrate (NO3-) to nitrite (NO2-) by bacteria is - Answer an anaerobic
process
Which of the following is true regarding the electron transport chain of Bacteria living within
giant tube worms near volcanic sea vents - Answer uses sulfide as electron donor and
oxygen as electron acceptor
Which of the following is NOT an example of a mutualistic relationship between two organisms -
Answer plasmodium falciparum and humans
The light organ of the hawaiian bobtail squid produces light only at night because: - Answer
vibrio fisheri in the light organ only grows to a high cell density at night producing
acylhomoserine lactones above a threshold concentration
Which of the following is the first step of the biofilm formation process - Answer attachment
of planktonic cells to a surface
with Solved Solutions 2025-2026
Updated.
Which of the following family of viruses have DNA genomes - Answer Hepadnaviridae
The single stranded negative strand RNA of a virus - Answer must be converted to positive
strand RNA in order to be translated into proteins
The distinction between a prion and a virus is that - Answer A prion is a single protein
molecule whereas a virus may contain many copies of one or several proteins
The Pasteur Swan Neck flask experiment shows that - Answer microorganisms are present in
air and they can contaminate a nutrient rich broth
The Koch's postulate is used to - Answer determine which organism causes a particular
infectious disease
Which type of microscopy can be used to study the interior structures of a live bacteria? -
Answer phase contrast
Which of the following techniques can be used to observe ribosomes within a cell - Answer
Transmission electron microscopy
Which of the following microorganisms belong to the domain Archea - Answer Methanogens
Which of the following structures below can be found in the cell wall of a Gram positive
bacteria? - Answer teichoic acid
An absent-minded laboratory technician forgot the ethanol wash step in his gram negative
staining procedure. As a result; - Answer Both Gram positive bacteria and Gram negative
bacteria are stained purple
Which of the following contains 80S ribosomes - Answer ribosomes attached to the
membrane of rough endoplasmic reticulum
Which of the following contain proteins involved in the electron transport chain? - Answer
bacterial cytoplasmic membrane
, Which of the following explains the mechanism of chemotaxis in bacteria? - Answer If a
bacterium senses that it is moving towards a nutrient source, its flagella will rotate anti-
clockwise more frequently than clockwise
How does facilitated diffusion resemble active transport - Answer membrane proteins are
requires in both processes
Which of the following best describes what happens to a bacterium when it is placed in a
solution containing a high concentration of sodium chloride - Answer water will move out of
cell by osmosis
__________ is the product of ancestral engulfment of a prokaryotic cell according to the theory
of endosymbiosis - Answer chloroplast
Which of the following statements regarding microorganisms from the domain Archea is false? -
Answer some members can cause disease in humans
Which of the following is a characteristic of fungi - Answer they are heterotrophs
You grew two different bacteria, x and y, in test tube cultures without shaking. After several days
you made the following observations - Answer x is an aerobe while y is a facultative
anaerobe
The conversion of nitrate (NO3-) to nitrite (NO2-) by bacteria is - Answer an anaerobic
process
Which of the following is true regarding the electron transport chain of Bacteria living within
giant tube worms near volcanic sea vents - Answer uses sulfide as electron donor and
oxygen as electron acceptor
Which of the following is NOT an example of a mutualistic relationship between two organisms -
Answer plasmodium falciparum and humans
The light organ of the hawaiian bobtail squid produces light only at night because: - Answer
vibrio fisheri in the light organ only grows to a high cell density at night producing
acylhomoserine lactones above a threshold concentration
Which of the following is the first step of the biofilm formation process - Answer attachment
of planktonic cells to a surface
