Final answer:
Enveloped viruses have a lipid bilayer, non-enveloped viruses lack a protein coat, and a virion is a complete viral particle.
Step-by-step explanation:
Enveloped viruses have a lipid bilayer, while non-enveloped viruses lack a protein coat. A virion is a complete viral particle consisting of a nucleic acid core, an outer protein coating or capsid, and sometimes an outer envelope made of protein and phospholipid membranes derived from the host cell. The complexity of the host does not necessarily correlate with the complexity of the virion. Some of the most complex virion structures are found in bacteriophages, viruses that infect bacteria.