They require both RNA and DNA

they both need food molecules

they both require oxygen for respiration

both require the environment of a cell to replicate.

Viruses possess their own metabolic system.

All viruses contain both RNA and DNA .

Viruses are obligate parasites.

Nucleic acid of viruses is known as capsid.

300 $$ \times $$ 10 nm

300 $$ \times $$ 5 nm

300 $$ \times $$ 20 nm

700 $$ \times $$ 30 nm

are always circular

are always linear

can be either circular or linear, but never both within the same cell

can be circular as well as linear within the same cell.