Mcb3023- Exam 1 modules 1.1-1.4
Actual Test Questions with Complete
Solutions 2026 Updated.
The bacterial chromosome is a highly condensed structure that is tightly wound up around itself
to fit into the bacterial cell. What is the main enzyme responsible for condensing the DNA? -
Answer DNA topoisomerase
The discovery of ribozymes provides evidence that life on the early Earth may have been based
on - Answer RNA
Which of these is considered to be the smallest unit of life? - Answer cell
A chemoautotroph: - Answer obtains carbon and energy from inorganic molecules
Which of the characteristics of life is not displayed by any individual organism? - Answer
evolution
Which is the correct distinction between a heterotroph and an autotroph? - Answer An
autotroph utilizes carbon dioxide as a carbon source and a heterotroph utilizes organic
compounds as a carbon source.
In which of these are Archaea and Bacteria significantly different? - Answer membrane lipid
structure
In which of these aspects do Archaea DIFFER from Eukarya - Answer Being haploid in
chromosome number while Eukarya are diploid
What are the two lines of evidence that support the Endosymbiotic Theory for the origin of
chloroplasts? - Answer They divide by binary fission and they contain DNA
When would you speculate that the extinction of most eukaryal life forms without mitochondria
would have begun? - Answer 2 billion
Movement of the eukaryal cilia and flagella involves interaction between dynein motor proteins
and _____ - Answer microtubules
,Which medium is used to obtain maximum yield of any pure culture? - Answer nutrient-rich
general purpose
Which of these methods will NOT ensure sterility? - Answer Pasteurization
During steady state growth in a chemostat, the growth rate of the cells is equivalent to: -
Answer the dilution rate
You are using triple sugar iron agar to differentiate intestinal bacteria. You believe you have
isolated Shigella. What appearance would you see in the culture tube? - Answer Red slant,
yellow butt
Which of these are fossilized microbial mats containing photosynthesis bacteria? - Answer
stromatolites
Which term describes straight, rod-shaped bacteria? - Answer bacilli
Which statement below is false concerning the atmosphere of the early Earth? - Answer
Carbon dioxide was present in very minute amounts
Which is the major component of the cell wall in the microbes in the Bacteria domain? - Answer
peptidoglycan
Which is an example of an inclusion body found in a bacterial cell? - Answer
polyhydroxybutyrate
The glycan portion of peptidoglycan is composed of alternating units of which two compounds?
- Answer N-acetylmuramic acid and N-acetylglucosamine (NAM and NAG)
Some bacteria produce sterol-like molecules called __________________ that help to stabilize
the plasma membrane - Answer hopanoids
What is the function of the bacterial capsule? - Answer all of the above:
Preventing phagocytosis by phagocytic cells
Resisting desiccation
Attachment
, In which molecule is the occurrence of mutations most likely to be detected and repaired? -
Answer double stranded DNA
Which best describes the cyanobacteria? - Answer Carry out oxygenic photosynthesis
The Endosymbiotic Theory supports - Answer Presence of mitochondria in eukaryotes
The MreB protein in bacteria may play an important role in - Answer Determining cell shape
Given the size of a typical ribosome, how many would you expect to find inside a typical
bacterium of 1-5um size? - Answer 1000-5000 ribosomes
Which of these constitute valid reasons why action polymer formation by Shigella should be
considered as a strong virulence factor? - Answer Actin polymers allow bacteria to invade an
epithelial sheet without immune cell exposure
A restriction endonuclease cuts DNA at the sequence ACGT. If we assume that all four bases are
equally represented in DNA, what are the odds of this sequence occurring on a DNA strand? -
Answer Roughly every 250 base pairs
which of these is one of the main functions of the cytoplasmic membrane in Archaea? - Answer
it acts as a semi permeable membrane to the diffusion of molecules in and out of the cell
how many phyla in the archaea domain are well-characterized - Answer 2
proteins of extreme halophiles contain high amounts of the amino acid ________ and
_________ to help stabilize them in high salt environments - Answer aspartate, glutamate
the ICTV scheme uses all of the following to classify viruses EXCEPT: - Answer ribosomal RNA
sequence
ICTV classifies: presence and absence of envelope, virion morphology, type of nucleic acid
viruses contain, the host viruses infect
what is the viral capsid composed of - Answer protein
Amitochondriates are eukaryal microbes that lack mitochondria. What evidence shows that
some of these microbes may at one time have had mitochondria? - Answer They have some
DNA in their chromosome similar to that found in alpha-proteobacteria
Actual Test Questions with Complete
Solutions 2026 Updated.
The bacterial chromosome is a highly condensed structure that is tightly wound up around itself
to fit into the bacterial cell. What is the main enzyme responsible for condensing the DNA? -
Answer DNA topoisomerase
The discovery of ribozymes provides evidence that life on the early Earth may have been based
on - Answer RNA
Which of these is considered to be the smallest unit of life? - Answer cell
A chemoautotroph: - Answer obtains carbon and energy from inorganic molecules
Which of the characteristics of life is not displayed by any individual organism? - Answer
evolution
Which is the correct distinction between a heterotroph and an autotroph? - Answer An
autotroph utilizes carbon dioxide as a carbon source and a heterotroph utilizes organic
compounds as a carbon source.
In which of these are Archaea and Bacteria significantly different? - Answer membrane lipid
structure
In which of these aspects do Archaea DIFFER from Eukarya - Answer Being haploid in
chromosome number while Eukarya are diploid
What are the two lines of evidence that support the Endosymbiotic Theory for the origin of
chloroplasts? - Answer They divide by binary fission and they contain DNA
When would you speculate that the extinction of most eukaryal life forms without mitochondria
would have begun? - Answer 2 billion
Movement of the eukaryal cilia and flagella involves interaction between dynein motor proteins
and _____ - Answer microtubules
,Which medium is used to obtain maximum yield of any pure culture? - Answer nutrient-rich
general purpose
Which of these methods will NOT ensure sterility? - Answer Pasteurization
During steady state growth in a chemostat, the growth rate of the cells is equivalent to: -
Answer the dilution rate
You are using triple sugar iron agar to differentiate intestinal bacteria. You believe you have
isolated Shigella. What appearance would you see in the culture tube? - Answer Red slant,
yellow butt
Which of these are fossilized microbial mats containing photosynthesis bacteria? - Answer
stromatolites
Which term describes straight, rod-shaped bacteria? - Answer bacilli
Which statement below is false concerning the atmosphere of the early Earth? - Answer
Carbon dioxide was present in very minute amounts
Which is the major component of the cell wall in the microbes in the Bacteria domain? - Answer
peptidoglycan
Which is an example of an inclusion body found in a bacterial cell? - Answer
polyhydroxybutyrate
The glycan portion of peptidoglycan is composed of alternating units of which two compounds?
- Answer N-acetylmuramic acid and N-acetylglucosamine (NAM and NAG)
Some bacteria produce sterol-like molecules called __________________ that help to stabilize
the plasma membrane - Answer hopanoids
What is the function of the bacterial capsule? - Answer all of the above:
Preventing phagocytosis by phagocytic cells
Resisting desiccation
Attachment
, In which molecule is the occurrence of mutations most likely to be detected and repaired? -
Answer double stranded DNA
Which best describes the cyanobacteria? - Answer Carry out oxygenic photosynthesis
The Endosymbiotic Theory supports - Answer Presence of mitochondria in eukaryotes
The MreB protein in bacteria may play an important role in - Answer Determining cell shape
Given the size of a typical ribosome, how many would you expect to find inside a typical
bacterium of 1-5um size? - Answer 1000-5000 ribosomes
Which of these constitute valid reasons why action polymer formation by Shigella should be
considered as a strong virulence factor? - Answer Actin polymers allow bacteria to invade an
epithelial sheet without immune cell exposure
A restriction endonuclease cuts DNA at the sequence ACGT. If we assume that all four bases are
equally represented in DNA, what are the odds of this sequence occurring on a DNA strand? -
Answer Roughly every 250 base pairs
which of these is one of the main functions of the cytoplasmic membrane in Archaea? - Answer
it acts as a semi permeable membrane to the diffusion of molecules in and out of the cell
how many phyla in the archaea domain are well-characterized - Answer 2
proteins of extreme halophiles contain high amounts of the amino acid ________ and
_________ to help stabilize them in high salt environments - Answer aspartate, glutamate
the ICTV scheme uses all of the following to classify viruses EXCEPT: - Answer ribosomal RNA
sequence
ICTV classifies: presence and absence of envelope, virion morphology, type of nucleic acid
viruses contain, the host viruses infect
what is the viral capsid composed of - Answer protein
Amitochondriates are eukaryal microbes that lack mitochondria. What evidence shows that
some of these microbes may at one time have had mitochondria? - Answer They have some
DNA in their chromosome similar to that found in alpha-proteobacteria
