Life has two characteristics: organized and replicates itself. Some scientists argue that because viruses are not traditional cells and cannot replicate without a host, they are not alive . But viruses are highly organized even if you couldn"t quite call them cellular. They use the same kind of genetic storage as living cells and they replicate, admittedly with help, they mutate and they even evolve like other living things. Your text and many scientists find it hard not to treat viruses as living things. Viruses like this (this is corona virus) they all have a structure. They have a protein coat that surrounds them, we also call that the capsid, with a core containing nucleotides. These nucleotides are either dna or rna but cannot be both at the same time. This differentiates them from living things as we know them.