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NurseDive Free Nursing Practice Question
A ____________ is a clear zone on a bacterial lawn where cells have been killed by the
A. activity of a bacteriophage.
activity of a bacteriophage: This describes the cause of the clear zone, since bacteriophages infect and lyse bacterial cells, but it is not the correct term used for the zone itself.
B. colony
colony: A colony is a visible cluster of bacterial cells originating from a single progenitor cell, not a clear zone caused by viral lysis.
C. plaque
plaque: A plaque is the clear area formed on a bacterial lawn where bacteriophages have infected and destroyed bacterial cells. It represents viral activity and spread.
D. lawn
lawn: A lawn refers to the uniform layer of bacterial growth on the agar surface, which serves as the background where plaques can be observed.
E. culture
A culture is the overall growth of microorganisms in a medium, not the specific clear zone produced by bacteriophage activity.
This question is an excerpt from Nurse Dive's nursing test bank - Fa25 biol Microbiology (Hennepin Technical College) proctored exam. Take the full exam now
Full Explanation
A. activity of a bacteriophage: This describes the cause of the clear zone, since bacteriophages infect and lyse bacterial cells, but it is not the correct term used for the zone itself.
B. colony: A colony is a visible cluster of bacterial cells originating from a single progenitor cell, not a clear zone caused by viral lysis.
C. plaque: A plaque is the clear area formed on a bacterial lawn where bacteriophages have infected and destroyed bacterial cells. It represents viral activity and spread.
D. lawn: A lawn refers to the uniform layer of bacterial growth on the agar surface, which serves as the background where plaques can be observed.
E. culture: A culture is the overall growth of microorganisms in a medium, not the specific clear zone produced by bacteriophage activity.
Similar Questions
Prions are composed of
A. protein only.
protein only: Prions are infectious agents made entirely of misfolded proteins without nucleic acids. They propagate by inducing normal cellular proteins to misfold, leading to neurodegenerative diseases.
B. an RNA surrounded by a protein capsid.
an RNA surrounded by a protein capsid: This describes a typical RNA virus, not a prion. Viruses contain nucleic acids, while prions lack them completely.
C. circular RNA only.
circular RNA only: Circular RNA molecules are found in viroids, which infect plants, but prions are distinct as they are composed solely of protein.
D. circular DNA only.
circular DNA only: Circular DNA is present in some viruses and plasmids, but prions do not contain DNA or any form of nucleic acid.
Full Explanation
A. protein only: Prions are infectious agents made entirely of misfolded proteins without nucleic acids. They propagate by inducing normal cellular proteins to misfold, leading to neurodegenerative diseases.
B. an RNA surrounded by a protein capsid: This describes a typical RNA virus, not a prion. Viruses contain nucleic acids, while prions lack them completely.
C. circular RNA only: Circular RNA molecules are found in viroids, which infect plants, but prions are distinct as they are composed solely of protein.
D. circular DNA only: Circular DNA is present in some viruses and plasmids, but prions do not contain DNA or any form of nucleic acid.
All of the following methods are used to culture viruses in a lab, except
A. cell culture
cell culture: Viruses can be grown in cell cultures, where living host cells provide the machinery necessary for viral replication. This is a common laboratory method.
B. nutrient media
nutrient media: Viruses cannot grow on nutrient media alone because they require living host cells for replication. Nutrient media supports bacterial and fungal growth, not viruses.
C. lab animals
lab animals: Some viruses require whole organisms for propagation, so laboratory animals can be used as hosts to study pathogenesis and replication.
D. embryonated eggs
embryonated eggs: Embryonated chicken eggs provide a supportive environment for viral growth and are widely used for vaccine production, such as influenza vaccines.
Full Explanation
A. cell culture: Viruses can be grown in cell cultures, where living host cells provide the machinery necessary for viral replication. This is a common laboratory method.
B. nutrient media: Viruses cannot grow on nutrient media alone because they require living host cells for replication. Nutrient media supports bacterial and fungal growth, not viruses.
C. lab animals: Some viruses require whole organisms for propagation, so laboratory animals can be used as hosts to study pathogenesis and replication.
D. embryonated eggs: Embryonated chicken eggs provide a supportive environment for viral growth and are widely used for vaccine production, such as influenza vaccines.
What should you do if a microbial culture splashed in your eyes?
A. Rinse your eyes with water for at least 15 minutes and seek medical advice.
Rinse your eyes with water for at least 15 minutes and seek medical advice: Immediate flushing of the eyes with copious amounts of water helps remove microbial contaminants and reduce risk of infection. Seeking medical evaluation ensures further care if necessary.
B. Nothing. The cultures in this course are harmless.
Nothing. The cultures in this course are harmless: Assuming cultures are harmless is unsafe, as even nonpathogenic organisms can cause opportunistic infections, especially if they contact mucous membranes like the eyes.
C. Wipe my eyes with a damp paper towel
Wipe my eyes with a damp paper towel: Wiping is inadequate for decontamination and may worsen the situation by spreading microorganisms across the eye surface.
D. Wash my face with soap and water
Wash my face with soap and water: Washing the face does not adequately address exposure in the eyes. The correct action is prolonged eye irrigation to remove microbes effectively.
Full Explanation
A. Rinse your eyes with water for at least 15 minutes and seek medical advice: Immediate flushing of the eyes with copious amounts of water helps remove microbial contaminants and reduce risk of infection. Seeking medical evaluation ensures further care if necessary.
B. Nothing. The cultures in this course are harmless: Assuming cultures are harmless is unsafe, as even nonpathogenic organisms can cause opportunistic infections, especially if they contact mucous membranes like the eyes.
C. Wipe my eyes with a damp paper towel: Wiping is inadequate for decontamination and may worsen the situation by spreading microorganisms across the eye surface.
D. Wash my face with soap and water: Washing the face does not adequately address exposure in the eyes. The correct action is prolonged eye irrigation to remove microbes effectively.