30 Questions
What is the main function of the viral genome in directing the synthesis of viral components?
Formation of infectious progeny virions
What distinguishes viroids from viruses based on the provided text?
Viroids lack a protein coat
What is a prion?
Single protein molecule
Which ancient text mentions evidence of several viral diseases?
The Iliad by Homer
What initiates the next infectious cycle in viruses?
Progeny virion disassembly
How long have viruses been known as distinct biological entities?
Less than 100 years
What did Beijerinck term the submicroscopic agent responsible for tobacco mosaic disease?
Contagium vivum fluidum
Who identified viruses that cause leukemias or solid tumors in chickens in 1908 and 1911, respectively?
Vilhelm Ellerman and Olaf Bang
Who first recognized that bacteria could be hosts to viruses?
Friedrick Twort
What is the function of capsid in a virus?
Encloses the nucleic acid genome
When was the term 'virus' eventually simplified from contagium vivum fluidum?
1898
What did Loeffler and Frosch deduce about infectious filterable agents in 1898?
Comprised small particles
What was the practice called where healthy individuals were inoculated with material from smallpox pustules?
Variolation
What did variolation involve?
Inoculating healthy individuals with smallpox material
Who recognized the principle on which modern methods of viral immunization are based?
Edward Jenner
What observation led Edward Jenner to his great insight regarding smallpox protection?
Milkmaids contracted cowpox
What were the consequences of variolation according to the text?
Serious skin lesions at the site of inoculation and rash
What event occurred in the 11th century in China and India related to smallpox?
Widespread practice of variolation
What is a key difference between the nucleocapsids of viruses with helical symmetry and icosahedral structures?
Regular, periodic interaction between capsid protein and nucleic acid
Which type of genome is typically found in animal viruses with helical symmetry?
RNA genomes
What is a function of the structural proteins in viruses?
Facilitate transfer of viral nucleic acid
Which statement about the structure of paxoviruses is true?
Brick-shaped with ridges on the external surface
What determines the antigenic characteristics of a virus?
Structural proteins
Why is it not possible for 'empty' helical particles to form?
Regular, periodic interaction between capsid protein and nucleic acid
What is recommended if rubella is diagnosed in the first trimester of pregnancy?
Immediate pregnancy termination
Why is accurate laboratory identification of the infecting virus necessary for the use of antiviral agents?
To ensure effectiveness of the antiviral agent
In chronic diseases like HIV and hepatitis B virus, what is required to make decisions about therapy initiation?
Full understanding of laboratory findings
How are drug combinations for patients with viral infections typically selected?
According to the drug resistance profile of the infecting virus strain
What is the purpose of virus load testing in monitoring response to therapy?
To monitor the response and adjust therapy as needed
Why might blood banks screen for viruses like HIV and hepatitis B and C?
To prevent spread through blood transfusions
Learn about the fundamental characteristics of viruses, including their structure, genome composition, and replication process. Explore how viruses rely on host cells to replicate and spread. Test your knowledge on viral infections and transmission.
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