3 minute read
Quiz
by AudioLearn
QUIZ
1. What does the Baltimore classification relies on to make the differentiation between different types of viruses?
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a. The virus particle’s basic structure b. The type of nucleic acids in the genome c. The length of the viral particle’s genome d. The protein coat on the outside of the particle
Answer: b. The Baltimore classification is based on the type of nucleic acids in the virus particle’s genome. 2. What is the protein coat around the individual virus called?
a. Viral particle b. Virion c. Envelope d. Capsid
Answer: d. The capsid, which is the protein coat that surrounds the viral nucleic acid molecule in order to protect it, is seen on all viruses.
3. What viral hypothesis on the origin of these entities indicates that viral particles developed and evolved billions of years ago at the origin of life itself?
a. Vagrancy hypothesis b. Regression hypothesis c. Escape hypothesis d. Virus first hypothesis
Answer: d. The virus first hypothesis indicates that viruses developed and evolved since the beginning of life on earth and didn’t require cellular structures to help develop the virus particles. The other theories depend on cells to make the virus particle develop in the first place.
4. What is the capsid on a viral particle made from?
a. Lipid bilayers b. Capsomeres c. Pentons d. Hexons
Answer: b. Capsids are protein coats made from different proteins, known as capsomeres or “subunits” of the capsid. 5. Why is it harder to infect a plant with a virus than it is an animal?
a. Plants have thick cell walls that animals don’t have. b. Plant viruses have more ineffective machinery to allow for replication. c. Plants have better immune mechanisms than animal cells. d. Plant viruses are mainly RNA viruses that do not translate proteins well.
Answer: a. Plant cells have thick walls that aren’t seen in animal cells so the plant often has to be traumatized in some way in order to have it infect the cell.
6. How do viruses attach to the cells they infect?
a. There is random endocytosis of virus particles by the host cell. b. The protein on the virus attaches to a receptor on the host cell. c. There is a receptor on the virus that binds to a receptor on the host cell. d. There is lipid-to-lipid attachment of the virus and host cell.
Answer: b. There is a protein on the virus that attaches to a receptor on the host cell to allow for attachment.
7. What replication step in DNA viruses isn’t necessary when infecting bacterial cells as opposed to animal cells?
a. Getting through the cell wall of the bacterium. b. Synthesizing proteins for replication. c. Entering the nucleus of the cell. d. Injecting the genome into the cell.
Answer: c. Bacterial cells do not have nuclei so this particular step is not necessary for infecting bacterial cells and replicating the genome.
8. How do drugs like zidovudine work against the HIV virus?
a. They prevent budding of the virus outside of the host cell. b. They are reverse transcriptase inhibitor drugs. c. They prevent the making of viral proteins. d. They prevent attachment of the viral particles to the cell.
Answer: b. These are reverse transcriptase inhibitors, preventing the RNA from transcribing into DNA. This affects the virus but not the host cell.
9. Which type of vaccine is most likely to give disease to the vaccinated individual?
a. Attenuated vaccines b. Subunit vaccines c. Viral protein vaccines d. Killed virus vaccines
Answer: a. Attenuated vaccines contain live but weakened viral particles; they can mutate to a more virulent form or can infect those who are too immunocompromised to fight off the infection.
10. What is a virus particle called that can only infect a cell that has already been infected by another virus?
a. Attenuated virus b. Weak virus c. Satellite virus d. Provirus
Answer: c. A satellite virus is one that can only infect a cell that has already been infected by another viral particle.
