Quiz: Viruses

1. A virus consists of:
RNA or DNA and a cell membrane
RNA or DNA and a protein coat
RNA and DNA and a protein coat
proteins, cell membrane and RNA

2. How do viruses reproduce?
they divide by mitosis
sexually, by external fertilization
replication outside the host
inserting DNA into the host cell

3. Which of the following is smallest?
eukaryote cell
bacteria
bacteriophage
cell membrane protein

4. Retroviruses are different from viruses in that:
they have RNA instead of DNA
they can become dormant
they are symmetrical
all of these

5. Vaccines can be used to prevent viral infection by:
creating an immune response in the host
destroying any viruses that enter the host
creating a blocking protein on the cell
preventing replication of the virus

6. Antiviral drugs that are used after infection often prevent:
cell division
immune system degradation
reinfection by other viruses
uptake of the virus

7. Why do some viruses seem to go away and then return later, like a cold sore?
host has been infected with a different strain
the immune system forgot the virus
the virus had entered the lysogenic cycle
the virus mutated

8. Why is it difficult to develop vaccines for retroviruses?
their small size evades the immune system
RNA mutates more frequently than DNA
the capsid of retroviruses is resistant
vaccines can only target blood-borne pathogens

9. Viruses are often named by:
where they were first discovered
the scientist who discovered it
the animal that carries it
all of these

10. What happens after the virus has been taken up by the cell?
it begins making protein
it divides
it inserts into the host DNA
it switches to infectious mode