As a consequence of the immune system in humans recognizing dsRNA as foreign,
A) dsRNA viruses rarely infect humans.
B) dsRNA viruses quickly transcribe their genes into mRNA which is insensitive to immune responses.
C) genomes of RNA viruses are often chemically modified to avoid recognition by human immune cells.
D) the genomes of dsRNA viruses must avoid human immune cells during infection, including replicating their genomes within their own nucleocapsids.
To promote the translational activity of ribosomes in human cells for synthesizing viral proteins during viral infection, viruses
A) chemically modify (e.g., cap and methylate) the transcripts.
B) keep a ribosome binding site specific to human ribosomes on their genome.
C) maintain introns and sometimes extrons in their genomes to appear as eukaryotic mRNA.
D) only adhere to and infect metabolically active host cells where protein synthesis is high.
The family of reoviruses contain dsRNA genomes that replicate from the template of ________ which makes it a ________ replication process.
A) only the positive ssRNA strand / conservative
B) only the positive ssRNA strand / semiconservative
C) both RNA strands /conservative
D) both RNA strands / semiconservative
What is the purpose of synthesizing a negative strand RNA in positive stranded ssRNA viruses?
A) enable rolling circle amplification of the genome, which requires both strands of RNA
B) enable transcription of genes occurring on both the negative and positive strands of the genome, such as overlapping genes
C) proofreading of the genome to minimize mutations generated by the polymerase being passed onto virion progeny
D) to serve as the complementary template sequence in genome amplification of the positive strand
Among the largest RNA genome viruses are ________ which contain a ________ genome.
A) coronaviruses / dsRNA
B) coronaviruses / positive ssRNA
C) polioviruses / dsRNA
D) polioviruses / positive ssRNA
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