Multiple choice ___________ are enveloped viruses. Omsk hemorrhagic fever viruses Orthomyxo viruses The Murray Valley Encephalitis Viruses (MVEV) Mump Reveal answer Fill a bubble to check yourself B Correct answer Explanation Orthomyxoviruses (influenza A, B, and C viruses) are enveloped viruses that contain single-stranded RNA in a helical array of nucleoprotein. Inserted in the lipid envelop are two glycoproteins- the hemagglutinin (HA) and the neuraminidase (NA).