Question

For ss (+) RNA viruses, which protein is responsible for copying the genome?

1 the ribosome

2 the RNA-dependent RNA polymerase (RdRp)

3 DNA-dependent DNA polymerase

4 the reverse transcriptase

Answer 1

For ss (+) RNA viruses, the RNA-dependent RNA polymerase (RdRp) protein is responsible for copying the genome.

explanation :- +ssRNA is a single stranded RNA called sense RNA. In +ssRNA viruses , genomic RNA is identical to mRNAs and hence easily recognized by host cell machinery for protein synthesis. The viral RNA molecule can directly translated by the host cell ribosomes to make viral protein. They contain RdRp ( RNA dependent RNA polymerase) to replicate their own viral genome.