Virus Review Questions 1. Explain why viruses are not considered to be living organisms. 2. Describe 2 structures that are characteristic of all viruses. 3. Differentiate between the lytic and lysogenic cycle. 4. Describe the structure of viroids and prions. 5. Why is it possible for some viral diseases to remain undetected for years? 1. Explain why viruses are not considered to be living organisms. Answer: Viruses are not considered to be living because they cannot reproduce on their own, do not grow, do not carry out metabolic activities, and are not made of cells. 2. Describe 2 structures that are characteristic of all viruses. Answer: Nucleic Acids (DNA or RNA) and a capsid 3. Differentiate between the lytic and lysogenic cycle. Answer: The lytic cycle involves rupturing the host cell to produce new viruses. The lysogenic cycle involves viral genetic material becoming embedded in the host cell and being replicated with the host cell. 4. Describe the structure of viroids and prions. Answer: Viroids are a single strand of RNA that can replicate inside a host cell. Prions are misshapen versions of proteins that cause normal proteins to change shape and stop functioning. 5. Why is it possible for some viral diseases to remain undetected for years? Answer: Lysogenic viruses can remain undetected inside a host cell for years. The viral genetic material is replicated with the host cell and does not cause any symptoms. Eventually, the virus may enter the lytic cycle and cause illness in the host.