microbiology final straighterline,
Straighterline Micro 250 final prep Exam
2026 Questions and Answers
The study of evolutionary relationships among organisms is called ______. -
Correct answer-phylogeny
The three cell types discussed, eukaryotes, archaea, and bacteria, all derived from
______. - Correct answer-Last Universal Common Ancestor
Organisms called parasites are ______. - Correct answer-always harmful to their
host
Which of the following does not indicate microbe involvement in energy and
nutrient flow? - Correct answer-Thermal hot springs warmed by heat from earth's
interior
The subatomic particles that surround the nucleus are the ______. - Correct
answer-Electrons
©COPYRIGHT 2025, ALL RIGHTS RESERVED 1
,The number one worldwide infectious diseases are ______. - Correct answer-
respiratory disease
A fat is called _____ if all carbons of the fatty acid chain are single-bonded to 2
other carbons and 2 hydrogens. - Correct answer-saturated
One technique for staining bacteria for viewing under the microscope is called the
Gram stain. In this technique, alcohol is used as a decolorizer because it degrades
the outer membrane found in some bacteria. What chemical component of the cell
does alcohol affect? - Correct answer-lipid
If a microbiologist is studying a specimen at a total magnification of 950X, what is
the magnifying power of the objective lens if the ocular lens is 10X? - Correct
answer-95X
NASA has published a list of criteria for identifying fossil bacteria in samples from
Mars, as part of a search for evidence of life. Which of the following is good
evidence for the presence of bacterial cells? - Correct answer-cell size of 0.5 to 2
microns
Which type of microscope achieves the greatest resolution and highest
magnification? - Correct answer-electron
©COPYRIGHT 2025, ALL RIGHTS RESERVED 2
,Which of the following is produced by adding 1% to 5% agar to nutrient broth that
is then boiled and cooled? - Correct answer-a solid medium
a spongiform encephalopathy of humans - Correct answer-Creutzfeldt-Jacob
disease
The term that refers to flagella at both poles of the cell is ______. - Correct
answer-amphitrichous
In the condition called athlete's foot, the fungus Trichophyton consumes the keratin
protein found in hair, nails, and dead skin. Which of the following descriptors does
not apply to Trichophyton? - Correct answer-saprobe
During the Gram stain, the application of alcohol results in the decolorization of
______ cells. - Correct answer-gram-negative
The size of a eukaryotic ribosome is ______ - Correct answer-80s
Sterilizing filters have a pore size of 0.22 μm. Which of the following statements is
true? - Correct answer-Bacterial cells are typically between 1-10 μm and are
blocked by the filter, whereas most viruses are between 20 and 200 nm and
therefore pass through.
One of the principal viral capsid shapes is a 20-sided figure with 12 evenly spaced
corners referred to as a/an _____ capsid. - Correct answer-icosahedral
©COPYRIGHT 2025, ALL RIGHTS RESERVED 3
, Amoebic dysentery is most commonly contracted through - Correct answer-fecal
oral
the viral genome inserting into bacterial host chromosome - Correct answer-
lysogeny
Which of the following is not associated with every virus? - Correct answer-
envelope
When bacilli in a chain fold back upon each other like a hinge, this cellular
arrangement is termed a ______. - Correct answer-palisade
proteins associated with DNA in the nucleus. - Correct answer-histones
Viral tissue specificities are called ______. - Correct answer-tropisms
the term that refers to the presence of a tuft of flagella emerging from a single site
is ______. - Correct answer-lophotrichous
E. coli bacteria normally live in the human gut and produce vitamin K that the
body uses. This is best termed a ______ relationship. - Correct answer-mutualistic
Termites are insects that require the protozoan Trichonympha in their gut to
synthesize the enzyme cellulase to degrade the cellulose in wood. The protozoan
uses the end products of the cellulose breakdown (glucose). This is a(n) ______
relationship. - Correct answer-mutualistic
©COPYRIGHT 2025, ALL RIGHTS RESERVED 4
Straighterline Micro 250 final prep Exam
2026 Questions and Answers
The study of evolutionary relationships among organisms is called ______. -
Correct answer-phylogeny
The three cell types discussed, eukaryotes, archaea, and bacteria, all derived from
______. - Correct answer-Last Universal Common Ancestor
Organisms called parasites are ______. - Correct answer-always harmful to their
host
Which of the following does not indicate microbe involvement in energy and
nutrient flow? - Correct answer-Thermal hot springs warmed by heat from earth's
interior
The subatomic particles that surround the nucleus are the ______. - Correct
answer-Electrons
©COPYRIGHT 2025, ALL RIGHTS RESERVED 1
,The number one worldwide infectious diseases are ______. - Correct answer-
respiratory disease
A fat is called _____ if all carbons of the fatty acid chain are single-bonded to 2
other carbons and 2 hydrogens. - Correct answer-saturated
One technique for staining bacteria for viewing under the microscope is called the
Gram stain. In this technique, alcohol is used as a decolorizer because it degrades
the outer membrane found in some bacteria. What chemical component of the cell
does alcohol affect? - Correct answer-lipid
If a microbiologist is studying a specimen at a total magnification of 950X, what is
the magnifying power of the objective lens if the ocular lens is 10X? - Correct
answer-95X
NASA has published a list of criteria for identifying fossil bacteria in samples from
Mars, as part of a search for evidence of life. Which of the following is good
evidence for the presence of bacterial cells? - Correct answer-cell size of 0.5 to 2
microns
Which type of microscope achieves the greatest resolution and highest
magnification? - Correct answer-electron
©COPYRIGHT 2025, ALL RIGHTS RESERVED 2
,Which of the following is produced by adding 1% to 5% agar to nutrient broth that
is then boiled and cooled? - Correct answer-a solid medium
a spongiform encephalopathy of humans - Correct answer-Creutzfeldt-Jacob
disease
The term that refers to flagella at both poles of the cell is ______. - Correct
answer-amphitrichous
In the condition called athlete's foot, the fungus Trichophyton consumes the keratin
protein found in hair, nails, and dead skin. Which of the following descriptors does
not apply to Trichophyton? - Correct answer-saprobe
During the Gram stain, the application of alcohol results in the decolorization of
______ cells. - Correct answer-gram-negative
The size of a eukaryotic ribosome is ______ - Correct answer-80s
Sterilizing filters have a pore size of 0.22 μm. Which of the following statements is
true? - Correct answer-Bacterial cells are typically between 1-10 μm and are
blocked by the filter, whereas most viruses are between 20 and 200 nm and
therefore pass through.
One of the principal viral capsid shapes is a 20-sided figure with 12 evenly spaced
corners referred to as a/an _____ capsid. - Correct answer-icosahedral
©COPYRIGHT 2025, ALL RIGHTS RESERVED 3
, Amoebic dysentery is most commonly contracted through - Correct answer-fecal
oral
the viral genome inserting into bacterial host chromosome - Correct answer-
lysogeny
Which of the following is not associated with every virus? - Correct answer-
envelope
When bacilli in a chain fold back upon each other like a hinge, this cellular
arrangement is termed a ______. - Correct answer-palisade
proteins associated with DNA in the nucleus. - Correct answer-histones
Viral tissue specificities are called ______. - Correct answer-tropisms
the term that refers to the presence of a tuft of flagella emerging from a single site
is ______. - Correct answer-lophotrichous
E. coli bacteria normally live in the human gut and produce vitamin K that the
body uses. This is best termed a ______ relationship. - Correct answer-mutualistic
Termites are insects that require the protozoan Trichonympha in their gut to
synthesize the enzyme cellulase to degrade the cellulose in wood. The protozoan
uses the end products of the cellulose breakdown (glucose). This is a(n) ______
relationship. - Correct answer-mutualistic
©COPYRIGHT 2025, ALL RIGHTS RESERVED 4
