Question

What blocks viral replication?

Answer 1

RNAi, restriction enzymes

Explanation:

RNAi
RNAi is short for RNA interference. During RNAi small RNA molecules, miRNA or siRNA, are used to form a complex which is complementary to the viral/foreign RNA. These RNA (both siRNA and miRNA) bind to mRNA from the virus, thus creating double stranded RNA. This dsRNA is then recognized by the RISC loading complex. This complex will make sure that the mRNA gets chopped up and recycled by the cell

Another way in which RNAi takes place is the inhibition of replication before a RISC complex is available. The siRNA and miRNA molecules can bind to the mRNA, thus blocking this mRNA. This makes sure that the ribosomes will not be able to translate this mRNA.

restricition enzymes
Restriction enzymes recognize specific base pair sequences which a cell (or plasmid) has encountered before. These restriction enzymes will then cleave the DNA or RNA at these specific sequences, ensuring that the genetic information is not replicated.