what features of life do they exhibit?
They resemble organisms in a way that they possess genes, evolve by natural selection, and reproduce by creating multiple copies of themselves through self-assembly. However, they do not have a cellular structure, which is often seen as the basic unit of life.
Virus
Scientific opinions differ on whether viruses are a form of life or organic structures that interact with living organisms. They have been described as "organisms at the edge of life", since they resemble organisms in that they possess genes, evolve by natural selection, and reproduce by creating multiple copies of themselves through self-assembly. Although they have genes, they do not have a cellular structure, which is often seen as the basic unit of life. 
when does the genetic material of a host and a virus combine Only when the host is infected by the virus. can you please define the latter term? It is a submicroscopic infectious agent that replicates only inside the living cells of an organism. how did it get its name? From the Latin word ”Virulent” that refers to poison.
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Virus [SEP] Life properties
Scientific opinions differ on whether viruses are a form of life or organic structures that interact with living organisms. They have been described as "organisms at the edge of life", since they resemble organisms in that they possess genes, evolve by natural selection, and reproduce by creating multiple copies of themselves through self-assembly. Although they have genes, they do not have a cellular structure, which is often seen as the basic unit of life. Viruses do not have their own metabolism and require a host cell to make new products. They therefore cannot naturally reproduce outside a host cell—although bacterial species such as rickettsia and chlamydia are considered living organisms despite the same limitation.