Straighterline Micro 250 final prep
Exam Latest Updated 2024 With
Complete Solutions
In a laboratory bacterial cell culture that has been infected by a virus, plaques are areas in which
Select one:
a. bacterial cells are resistant to the virus and have not been infected.
b. there is no nutrient available for the bacteria to grow.
c. the virus has spread and left behind the remains of dead cells.
d. the virus has not yet spread to that area of cells. - ANSWER-the virus has spread and left behind the
remains of dead cells.
The sun's energy is delivered as discrete packets that travel as waves and are called
Select one:
a. ATP.
b. carotenoids.
c. NADP.
d. photons. - ANSWER-photons.
Which of the following is a characteristic of aerobic respiration?
Select one:
a. Oxygen-containing ions act as the final electron acceptors in electron transport.
b. The process includes glycolysis, the Krebs cycle, and the electron transport chain.
c. Aerobic respiration produces a total of 2 ATP molecules.
d. Aerobic respiration produces lactic acid. - ANSWER-The three stages of aerobic respiration are glycolysis,
the Krebs cycle, and the electron transport chain.
n completing protein synthesis in a prokaryote, what basic message is carried by a specialized codon that
has no corresponding tRNA?
Select one:
a. "Fold peptide chain."
b. "Terminate here."
c. "Add cofactor."
d. "Clip starting amino acid." - ANSWER-"Terminate here." The specialized codon signals the end of protein
synthesis; there is not RNA because it is only needed if the process is to continue.
Microbial drug resistance can be caused by mutations or by introduction of new genes into a population.
Which of the following can only be caused by the introduction of new genes into a population?
Select one:
a. a metabolic pathway in the bacterium is shut down
b. binding sites for the drug are reduced in number or affinity to the drug
c. new enzymes that inactivate the drug are synthesized
d. uptake of the drug into the bacterium is diminished - ANSWER-new enzymes that inactivate the drug are
synthesized. This can only occur if new genes are introduced into the population.
Why do the hands, feet, and breasts have more lymphatic vessels for host defense than other areas of the
human body?
Select one:
a. They have a high risk for infection due to frequent contact.
b. They have a greater density of nerves.
c. They require complex movement of fluids from the extremities.
d. They are located a long distance from the thalamus. - ANSWER-They have a high risk for infection due to
frequent contact.
,Penicillin functions as an antimicrobial agent by inhibiting bacterial
Select one:
a. cell wall synthesis.
b. folic acid synthesis.
c. protein synthesis.
d. RNA and DNA function. - ANSWER-cell wall synthesis. Penicillin belongs to a class of antibacterial agents
that interfere with the production of the material that makes up the bacterial cell wall. The bacteria must
constantly replace this material or they will become susceptible to rupture due to osmotic pressure.
If enough ions are added to pure water to raise the concentration of the solution to ten times higher than the
original concentration, what is the resulting concentration of the solution? - ANSWER-
The study of evolutionary relationships among organisms is called - ANSWER-phylogeny
The three cell types discussed, eukaryotes, archaea, and bacteria, all derived from - ANSWER-Last
Universal Common Ancestor
Organisms called parasites are - ANSWER-always harmful to their host.
Which of the following does not indicate microbe involvement in energy and nutrient flow - ANSWER-
Thermal hot springs warmed by heat from earth's interior
The subatomic particles that surround the nucleus are the - ANSWER-Electrons
The number one worldwide infectious diseases are - ANSWER-respiratory diseases
A fat is called _____ if all carbons of the fatty acid chain are single-bonded to 2 other carbons and 2
hydrogens. - 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? - 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? - 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? - ANSWER-
cell size of 0.5 to 2 microns
Which type of microscope achieves the greatest resolution and highest magnification? - ANSWER-electron
Which of the following is produced by adding 1% to 5% agar to nutrient broth that is then boiled and cooled?
- ANSWER-a solid medium
a spongiform encephalopathy of humans - ANSWER-Creutzfeldt-Jacob disease
The term that refers to flagella at both poles of the cell is ______. - ANSWER-amphitrichous
Which class of eukaryotic microorganisms can be subdivided into groups such as Mastigophora, Sarcodina,
Ciliophora, and Apicomplexa?
A. Helminths
B. Algae
C. Protozoa
D. Fungi - ANSWER-Protozoa
, Genetic material can be excised from one chromosome and directly integrated into another via
A. conjugation.
B. transformation.
C. transduction.
D. transposons. - ANSWER-transposons.
Which immune cell secretes numerous cytokines that help to coordinate the response of other immune cells?
A. B cell
B. TH cell
C. TC cell
D. Platelets - ANSWER-TH cell
Which of the following enzymes are used to amplify DNA during PCR?
A. restriction endonuclease
B. DNA polymerase
C. reverse transcriptase
D. DNA ligase - ANSWER-DNA polymerase
In the nitrogen cycle, which of the following steps involves removal of nitrogen from the atmosphere by
bacteria? - ANSWER-nitrogen fixation, In nitrogen fixation, nitrogen is removed from the atmosphere by
nitrogen-fixing bacteria and converted to ammonia.
If enough h+ ions are added to pure water to raise the H+ concentration of the solution to ten times higher
than the original concentration, what is the resulting OH- concentration of the solution? - ANSWER-10 -8M
Fungi are able to reproduce asexually by creating conidiospores and sporangiospores. Which of the
following is an accurate explanation for why it is advantageous that they are also capable of sexual
reproduction?
Select one:
a. Asexually produced offspring are more likely to compete for resources and will kill off the parental fungi.
b. Fungi normally produce sexually but produce asexually in harsh conditions such as severe drought.
c. Offspring from two parents may have variations in form and function that contribute to survival of the
species.
d. Sexual reproduction produces more offspring at a faster rate than spore formation. - ANSWER-Offspring
from two parents may have variations in form and function that contribute to survival of the species.
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? - ANSWER-saprobe
During the Gram stain, the application of alcohol results in the decolorization of ______ cells. - ANSWER-
gram-negative
The size of a eukaryotic ribosome is _ - ANSWER-80s
Exam Latest Updated 2024 With
Complete Solutions
In a laboratory bacterial cell culture that has been infected by a virus, plaques are areas in which
Select one:
a. bacterial cells are resistant to the virus and have not been infected.
b. there is no nutrient available for the bacteria to grow.
c. the virus has spread and left behind the remains of dead cells.
d. the virus has not yet spread to that area of cells. - ANSWER-the virus has spread and left behind the
remains of dead cells.
The sun's energy is delivered as discrete packets that travel as waves and are called
Select one:
a. ATP.
b. carotenoids.
c. NADP.
d. photons. - ANSWER-photons.
Which of the following is a characteristic of aerobic respiration?
Select one:
a. Oxygen-containing ions act as the final electron acceptors in electron transport.
b. The process includes glycolysis, the Krebs cycle, and the electron transport chain.
c. Aerobic respiration produces a total of 2 ATP molecules.
d. Aerobic respiration produces lactic acid. - ANSWER-The three stages of aerobic respiration are glycolysis,
the Krebs cycle, and the electron transport chain.
n completing protein synthesis in a prokaryote, what basic message is carried by a specialized codon that
has no corresponding tRNA?
Select one:
a. "Fold peptide chain."
b. "Terminate here."
c. "Add cofactor."
d. "Clip starting amino acid." - ANSWER-"Terminate here." The specialized codon signals the end of protein
synthesis; there is not RNA because it is only needed if the process is to continue.
Microbial drug resistance can be caused by mutations or by introduction of new genes into a population.
Which of the following can only be caused by the introduction of new genes into a population?
Select one:
a. a metabolic pathway in the bacterium is shut down
b. binding sites for the drug are reduced in number or affinity to the drug
c. new enzymes that inactivate the drug are synthesized
d. uptake of the drug into the bacterium is diminished - ANSWER-new enzymes that inactivate the drug are
synthesized. This can only occur if new genes are introduced into the population.
Why do the hands, feet, and breasts have more lymphatic vessels for host defense than other areas of the
human body?
Select one:
a. They have a high risk for infection due to frequent contact.
b. They have a greater density of nerves.
c. They require complex movement of fluids from the extremities.
d. They are located a long distance from the thalamus. - ANSWER-They have a high risk for infection due to
frequent contact.
,Penicillin functions as an antimicrobial agent by inhibiting bacterial
Select one:
a. cell wall synthesis.
b. folic acid synthesis.
c. protein synthesis.
d. RNA and DNA function. - ANSWER-cell wall synthesis. Penicillin belongs to a class of antibacterial agents
that interfere with the production of the material that makes up the bacterial cell wall. The bacteria must
constantly replace this material or they will become susceptible to rupture due to osmotic pressure.
If enough ions are added to pure water to raise the concentration of the solution to ten times higher than the
original concentration, what is the resulting concentration of the solution? - ANSWER-
The study of evolutionary relationships among organisms is called - ANSWER-phylogeny
The three cell types discussed, eukaryotes, archaea, and bacteria, all derived from - ANSWER-Last
Universal Common Ancestor
Organisms called parasites are - ANSWER-always harmful to their host.
Which of the following does not indicate microbe involvement in energy and nutrient flow - ANSWER-
Thermal hot springs warmed by heat from earth's interior
The subatomic particles that surround the nucleus are the - ANSWER-Electrons
The number one worldwide infectious diseases are - ANSWER-respiratory diseases
A fat is called _____ if all carbons of the fatty acid chain are single-bonded to 2 other carbons and 2
hydrogens. - 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? - 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? - 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? - ANSWER-
cell size of 0.5 to 2 microns
Which type of microscope achieves the greatest resolution and highest magnification? - ANSWER-electron
Which of the following is produced by adding 1% to 5% agar to nutrient broth that is then boiled and cooled?
- ANSWER-a solid medium
a spongiform encephalopathy of humans - ANSWER-Creutzfeldt-Jacob disease
The term that refers to flagella at both poles of the cell is ______. - ANSWER-amphitrichous
Which class of eukaryotic microorganisms can be subdivided into groups such as Mastigophora, Sarcodina,
Ciliophora, and Apicomplexa?
A. Helminths
B. Algae
C. Protozoa
D. Fungi - ANSWER-Protozoa
, Genetic material can be excised from one chromosome and directly integrated into another via
A. conjugation.
B. transformation.
C. transduction.
D. transposons. - ANSWER-transposons.
Which immune cell secretes numerous cytokines that help to coordinate the response of other immune cells?
A. B cell
B. TH cell
C. TC cell
D. Platelets - ANSWER-TH cell
Which of the following enzymes are used to amplify DNA during PCR?
A. restriction endonuclease
B. DNA polymerase
C. reverse transcriptase
D. DNA ligase - ANSWER-DNA polymerase
In the nitrogen cycle, which of the following steps involves removal of nitrogen from the atmosphere by
bacteria? - ANSWER-nitrogen fixation, In nitrogen fixation, nitrogen is removed from the atmosphere by
nitrogen-fixing bacteria and converted to ammonia.
If enough h+ ions are added to pure water to raise the H+ concentration of the solution to ten times higher
than the original concentration, what is the resulting OH- concentration of the solution? - ANSWER-10 -8M
Fungi are able to reproduce asexually by creating conidiospores and sporangiospores. Which of the
following is an accurate explanation for why it is advantageous that they are also capable of sexual
reproduction?
Select one:
a. Asexually produced offspring are more likely to compete for resources and will kill off the parental fungi.
b. Fungi normally produce sexually but produce asexually in harsh conditions such as severe drought.
c. Offspring from two parents may have variations in form and function that contribute to survival of the
species.
d. Sexual reproduction produces more offspring at a faster rate than spore formation. - ANSWER-Offspring
from two parents may have variations in form and function that contribute to survival of the species.
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? - ANSWER-saprobe
During the Gram stain, the application of alcohol results in the decolorization of ______ cells. - ANSWER-
gram-negative
The size of a eukaryotic ribosome is _ - ANSWER-80s
