BIOL 1306 chap 21

The viral ________ play(s) a role in attaching a virion to the host cell. a. core b. capsid c. envelope d. both b and c

d. both b and c

Oncogenic virus cores can be_______. a. RNA b. DNA c. neither RNA nor DNA d. either RNA or DNA

d. either RNA or DNA

Vaccines_______. a. are similar to viroids b. are only needed once c. kill viruses d. stimulate an immune response

d. stimulate an immune response

Which of the following statements about virus structure is true? A. All viruses are encased in a viral membrane. B. The capsomere is made up of small protein subunits called capsids. C. DNA is the genetic material in all viruses. D. Glycoproteins help the virus attach to the host cell.

D. Glycoproteins help the virus attach to the host cell

Which statement is not true of viral replication? a. A lysogenic cycle kills the host cell. b. There are six basic steps in the viral replication cycle. c. Viral replication does not affect host cell function. d. Newly released virions can infect adjacent cells.

a. A lysogenic cycle kills the host cell.

A scientist discovers a new virus with a linear, RNA genome surrounded by a helical capsid. The virus is most likely a member of which family based on structure classification? a. Rabies virus b. Herpesviruses c. Retroviruses d. Influenza viruses

a. Rabies virus

An apple grower notices that several of his apple trees with fungi growing on their trunks have developed necrotic ring spots, while other trees in the orchard that lack fungi appear healthy. What is the most likely conclusion the farmer can make about the virus infecting his apple trees? a. The apple trees were infected by horizontal transmission. b. The fungi carry disease. c. The fungi attract disease-carrying insects. d. The apple trees were infected by vertical transmission.

a. The apple trees were infected by horizontal transmission.

Which statement is true of viroids? a. They are single-stranded RNA particles. b. They reproduce only outside of the cell. c. They produce proteins. d. They affect both plants and animals.

a. They are single-stranded RNA particles.

Which is true of DNA viruses? a. They use the host cell's machinery to produce new copies of their genome. b. They all have envelopes. c. They are the only kind of viruses that can cause cancer. d. They are not important plant pathogens.

a. They use the host cell's machinery to produce new copies of their genome.

Which statement is true of viral replication? a. In the process of apoptosis, the cell survives. b. During attachment, the virus attaches at specific sites on the cell surface. c. The viral capsid helps the host cell produce more copies of the viral genome. d. mRNA works outside of the host cell to produce enzymes and proteins

b. During attachment, the virus attaches at specific sites on the cell surface.

Which statement is true? a. A virion contains DNA and RNA. b. Viruses are acellular. c. Viruses replicate outside of the cell. d. Most viruses are easily visualized with a light microscope.

b. Viruses are acellular.

Which of the following statements is false? a. In the lytic cycle, new phages are produced and released into the environment. b. In the lysogenic cycle, phage DNA is incorporated into the host genome. c. An environmental stressor can cause the phage to initiate the lysogenic cycle d. Cell lysis only occurs in the lytic cycle.

c. An environmental stressor can cause the phage to initiate the lysogenic cycle

Which of the following is NOT used to treat active viral disease? a. Vaccines b. Antiviral drugs c. Antibiotics d. Phage therapy

c. Antibiotics

Which of the following is not associated with prions? a. Replicating shapes b. Mad cow disease c. DNA d. Toxic proteins

c. DNA

Which statement is true of reverse transcriptase? a. It is a nucleic acid. b. It infects cells. c. It transcribes RNA to make DNA. d. It is a lipid.

c. It transcribes RNA to make DNA...

A bacteriophage can infect ________. a. the lungs b. viruses c. prions d. Bacteria

d. Bacteria

Viruses_______. a. all have a round shape b. cannot have a long shape c. do not maintain any shape d. vary in shape

d. Vary in shape