Question

For bacteriophage with +ssRNA as their genome, which type of nucleic acid is used as the template for the production of more genomic RNA?

1) -ssRNA
2) dsRNA
3) -ssDNA
4) dsDNA

Answer 1

For bacteriophages with +ssRNA genomes, -ssRNA is used as the template by RNA-dependent RNA polymerase to create more +ssRNA genomic copies.

Step-by-step explanation:

For bacteriophages with a +ssRNA genome, the type of nucleic acid that is used as a template for the production of more genomic RNA is -ssRNA. This is because +ssRNA acts like cellular mRNA and can be directly translated into viral proteins. However, for replication, which includes the creation of new genomic RNA, the virus must first synthesize a complementary -ssRNA.

Then, using the -ssRNA as a template, it can produce more +ssRNA via the RNA-dependent RNA polymerase (RdRP). RdRP is a crucial enzyme that facilitates the replication process in positive-strand RNA viruses. Group IV viruses, as an example, create replicative intermediates of dsRNA, and ultimately, full-length -ssRNA copies are synthesized. These copies of -ssRNA then serve as templates for the synthesis of more +ssRNA genomic copies.