Viruses can be classifies by all of these methods except?

The methods of classifying viruses are:

- Genome type: This classifies viruses based on the type of genetic material they have, which can be either DNA or RNA.

- Structure: This classifies viruses based on their physical structure, such as their shape, size, and the presence or absence of an envelope.

- Replication strategy: This classifies viruses based on the way they replicate their genetic material.

- Host range: This classifies viruses based on the range of hosts they can infect.

Therefore, the only option that is not a method of classifying viruses is "symptoms".