Define virus and virion, and describe the parts of a virion.

A virus is a tiny infectious biological agent that can only replicate or duplicate inside the host cell. These infectious agents can infect all different types of living organisms ranging from animals and plants to microorganisms and archaea and bacteria.

Virions are ineffective particle or form of the virus outside of the host cell, with RNA or DNA and a protein capsid.

The main role of these infectious agent virions is to transfer the DNA or RNA genome from itself to the cell of host and expressed the gene which means produce proteins from the genome transferred to the host cell.

"1. it should be, it has been for about 20 years, and it's really not much different in the end than breeding animals to have particular traits. there are always concerns about genetically engineered animals/plants affecting the environment in unexpected negative ways, but i can't think of an example where the fears didn't turn out to be baseless.  

first, as you point out, it would be a great advance in pharmacology, to be able to tailor drugs and their doses to me. the pros involve better medical treatment. the cons involve privacy issues like insurance companies denying coverage to people with genetic risk factors. looking at dna markers wouldn't affect the frequency of genetic diseases, but it would allow detection of them earlier. and ok, actually i suppose that if people used this information to avoid having children with genetic diseases, some might decrease in frequency."