NDH VIROLOGY QUESTIONAS AND ANSWERS

NDH VIROLOGY What is a virus? Definition in three parts - 1. Obligate intracellular parasite- Requires host cell machinery 2. Submicroscopic "filterable" infectious agent 3. Possesses genetic material The structure and physical composition of a virus provides essential information on: Possible Test Answer - • Identification (How to classify it) • Pathogenesis (how it causes disease) • Diagnosis (how to detect it) • Treatment (how to control it) • Prevention (how to keep it out) Non-enveloped viruses - Protein Capsid (protective shell) Nucleic Acid Genome Enveloped viruses - Lipid envelope Acquired from host cell membrane Viral and host cell proteins embedded in the envelope Symmetrical Capsids - Icosahedral eg:Soccer ball Helical • eg:wrap around Complex capsid - no symettry Virus envelope - lipid bilayer material derived from nuclear membrane, endoplasmic