Final answer:
The Influenza virus is a single-stranded RNA virus with a helical capsid and envelope that is transmitted through respiratory secretions and is known for its ability to cause respiratory illness.
Step-by-step explanation:
The virus in question is most likely the Influenza virus, which is a highly contagious single-stranded RNA virus that is enclosed in a helical capsid and envelope. The influenza virus is transmitted primarily through direct contact and inhalation of respiratory aerosols. The virus's RNA genome is segmented into seven or eight parts, each encoding one or two proteins necessary for viral replication. These segments are surrounded by a protein complex and an envelope studded with spike proteins, which include hemagglutinin (H) and neuraminidase (N), that are essential for the virus's ability to infect host cells.
The Influenza virus falls under the Orthomyxoviridae family, which is known for its segmented single-stranded RNA genomes and the ability to cause widespread respiratory illness. The structure of this virus allows for easy mutation and antigenic shift, leading to different strains and the necessity for annual vaccination updates.