Which statement correctly describes the lysogenic cycle of a bacteriophage?
Viral DNA immediately directs host cell lysis after infection
Viral particles are released through budding from the host membrane
Viral RNA remains free in the host cytoplasm without replication
In lysogeny, viral DNA integrates into the host genome as a prophage
The host cell dies immediately following viral attachment
The Correct Answer is D
A. A: Immediate host cell lysis after infection characterizes the lytic cycle, not the lysogenic cycle. In the lytic pathway, viral DNA hijacks host machinery, replicates rapidly, and leads to destruction of the host cell. Lysogeny instead involves a dormant phase without immediate lysis.
B. B: Release of viral particles through budding from the host membrane is typical of enveloped animal viruses, not bacteriophages. Bacteriophages infect bacterial cells and do not use membrane budding as a release mechanism.
C. C: Viral RNA remaining free in the cytoplasm without replication does not describe lysogeny. In bacteriophages, the viral genome is DNA, and during lysogeny it integrates into the bacterial chromosome rather than remaining free and inactive in the cytoplasm.
D. D: In the lysogenic cycle, bacteriophage DNA integrates into the bacterial host genome and becomes a prophage. The viral DNA replicates passively along with the host chromosome during cell division without causing immediate cell death. This allows the virus to persist in a dormant state until conditions trigger entry into the lytic cycle.
E. Both A & E are correct: Immediate host cell death following attachment or infection describes the lytic cycle, not lysogeny. In lysogeny, the host cell survives and continues to replicate while carrying the integrated prophage within its genome.
Nursing Test Bank
Naxlex Comprehensive Predictor Exams
Related Questions
Correct Answer is B
Explanation
A. Yeasts are multicellular fungi that reproduce by spore fragmentation: Multicellular fungi, such as molds, have hyphal structures and can reproduce via spore formation or fragmentation of mycelia. Yeasts, however, are unicellular and do not form multicellular hyphae under normal conditions.
B. Yeasts are unicellular fungi that reproduce by budding: Yeasts are single-celled eukaryotic fungi that reproduce primarily through asexual budding, where a new daughter cell forms as an outgrowth from the parent cell. Their unicellular structure and budding reproduction distinguish them from filamentous fungi.
C. Yeasts are prokaryotic organisms that divide by binary fission: Prokaryotic organisms, such as bacteria, lack a nucleus and organelles and reproduce primarily by binary fission. Yeasts are eukaryotic, containing a true nucleus and membrane-bound organelles, and although some yeast species may divide by fission, they are classified as eukaryotes.
D. Yeasts are photosynthetic eukaryotes with chloroplasts: Photosynthesis is carried out by plants and certain protists possessing chloroplasts. Yeasts lack chloroplasts and do not perform photosynthesis; they obtain energy through fermentation or aerobic respiration, depending on environmental conditions.
Correct Answer is A
Explanation
Some bacteria, including Mycobacteriumand Nocardia, possess atypical cell walls that differ from typical gram-positive or gram-negative structures. Their cell walls contain high concentrations of mycolic acid, a waxy lipid that makes them resistant to standard Gram staining. Because of this unique composition, these bacteria require specialized staining techniques, such as the acid-fast stain, to be visualized under a microscope. The mycolic acid also contributes to their resistance to desiccation and certain antibiotics. Recognizing this characteristic is important in clinical microbiology for accurate identification and treatment of infections caused by these organisms.
Whether you are a student looking to ace your exams or a practicing nurse seeking to enhance your expertise , our nursing education contents will empower you with the confidence and competence to make a difference in the lives of patients and become a respected leader in the healthcare field.
Visit Naxlex, invest in your future and unlock endless possibilities with our unparalleled nursing education contents today
Report Wrong Answer on the Current Question
Do you disagree with the answer? If yes, what is your expected answer? Explain.
Kindly be descriptive with the issue you are facing.