SCIENCE
VIRUS AND BACTERIA
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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High mutation rate due to lack of proofreading of RNA genome replication errors.
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Transcription from the host cell RNA polymerase introduces numerous mutations.
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Capsid proteins from the host cell can replace the viral capsid.
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Viral RNA is translated by host cell ribosomes.
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Detailed explanation-1: -Genetic Change in Viruses This chapter covers the mechanisms by which genetic changes occur in viruses. Two principal mechanisms are involved: mutation and recombination. Alterations in the genetic material of a virus may lead to changes in the function of viral proteins.
Detailed explanation-2: -Viral variation can be generated by a number of mechanisms. Major rearrangements in genome structure and organisation can occur by genetic recombination. Gene duplications, gene exchanges and gene adoptions also occur. However, the most common form of variation is mutation by nucleotide substitution.
Detailed explanation-3: -Two mechanisms are the main sources of genetic variation in viruses during their evolutionary process: mutation and genetic exchange.
Detailed explanation-4: -RNA viruses are characterized by high mutation rates compared with most DNA systems (1), due mainly to the lack of exonuclease proofreading activity displayed by their RNA polymerases (2).