Transcription makes an RNA copy of part of the DNA.

Later in infection, the activity of the polymerase switches to replication in order to produce full-length positive-strand RNA copies.

In the example of foot-and-mouth disease virus, the ratio of whole virions to RNA copies within an actively replicating host cell is approximately 1:1000.

It is read and transcribed into RNA copies.

For example, it can be given in RNA copies per milliliter of blood plasma.

The positive- or plus-sense genome, then makes viral complementary RNA (vcRNA) copies of itself.

Once the additional RNA copies have been produced, they code for the synthesis of various proteins, as mentioned before, as well as coat proteins.

Every RNA copy of a gene has a little spot, called the Rev recognition element, where a Rev protein binds.

The RNA copy of each gene provides the blueprint for the cell to make the protein specified by that gene.

Sharp's explanation is that they travelled via an RNA copy.