Bio 171 Module 6 exam Portage Learning

Microbiology Module 6 Review Can viruses be classified as either prokaryotic or eukaryotic microorganisms? No. Viruses are considered neither prokaryotic nor eukaryotic. What is an obligate intracellular parasite? Parasite virus that is not able to replicate unless inside a living host a parasite relies on its host to replicate. What is a viral capsid? Is a membrane-like protective structure that contains the genetic material, similar to the nucleus of a eukaryotic cell. What is the viral envelope, and what does the presence (or absence) of it tell you about the type of virus? The envelope surrounds the viral capsid, is derived from the host cell membrane, and serves as an additional barrier to the external environment. What type of microscope would be used to study the shape of a viral capsid? 30-150nm most viral capsids must be visualized by electron microscopy How does the viral envelope both aid in cell entry as well as hide it from being detected by the immune system? The viral envelope contains the necessary proteins required for interaction with host cells. As the envelope is derived from the host cell membrane, this camouflages the virus and lowers the likelihood of immune detection by making it appear similar to the normal biological host cell. What must happen before viral replication of its genome can occur? For all viruses, the genome is replicated following attachment and entry, never before. Describe the basic steps of the viral life cycle. 1. Attachment: Viral receptors bind to host proteins on the surface of the cell. 2. Entry: The virus fuses with the host membrane and enters the cell 3. Uncoating: The viral capsid disassembles