Microbiology Chapter 6 Practice

Viral nucleic acid is made inside the bacterium and is combined with viral protein coat already present outside. True or False?

False

Viral replication follows essentially the same steps as replication of a prokaryotic cell. True or False?

False

Virus are classified into species based on whether they can reproduce to produce fertile offspring, much like plants and animals. True or False?

False

The viral-host relationship is extremely important for pathogenicity, mode of transmission, the immune response, and the human measures used to control viral infections. True or False?

True

Viral lysozyme digests the host cell wall, releasing the newly made phage, and lysing the host cell in the release step. True or False?

True

Viral nucleic acid enters the host cell and uses host cell's replication and synthesis machinery in order to produce new nucleic acid molecules, proteins for the capsid, spikes, and viral enzymes. True or False?

True

The correct order of the stages for phage replication are 1 = Assembly2 = Attachment3 = Transcription/replication4 = Release5 = Penetration Multiple Choice a. 5, 2, 3, 1, 4 b. 2, 5, 3, 1, 4 c. 2, 5, 1, 3, 4 d. 5, 2, 1, 3, 4

b. 2, 5, 3, 1, 4

The stage of T4 replication that involves the protein fibers on the phage and receptors on the bacterial cell wall is the Multiple Choice a. assembly stage. b. attachment stage. c. lysis stage. d. transcription stage. e. penetration stage.

b. attachment stage.

A positive sense strand lytic RNA phage attaches to the cell wall of an E. coli bacterium. True or False?

False

During the transcription stage, the phage DNA merges with the host DNA. True or False?

False

If the virus is present as a provirus in the host cell, it remains latent and never produces new virus. True or False?

False

In the lysogenic stage of phage replication, the host cell is lysed. True or False?

False

Most viral infections result in the death of the host. True or False?

False

Once a phage becomes lysogenic, it will remain lysogenic and never be lytic again. True or False?

False

The envelope is entirely formed from viral material. True or False?

False

The light microscope was critical in the discovery of viruses. True or False?

False

The use of antibiotics is an effective treatment for viral infections. True or False?

False

Viruses are routinely cultured in order to diagnose an infection. True or False?

False

Viruses first appeared on Earth sometime after the rise of eukaryotic organisms. True or False?

False

A phage-induced lysozyme lyses the host cell releasing the newly made phage. True or False?

True

A portion of the viral envelope comes from the cell membrane of the host cell. True or False?

True

Enveloped viruses are usually released from the host cell by budding. True or False?

True

The enzyme lysozyme is used by the T4 phages to enter and exit the host cell. True or False?

True

The hepadnavirus family is so named because viruses within the family infect the liver and possess DNA as their genetic material. True or False?

True

The polygenic mRNA codes for making one long polyprotein, which is then cleaved into the separate individual virus proteins. True or False?

True

__________ are the only active biological agents lacking any nucleic acid (DNA or RNA). Multiple Choice a. Prions b. Satellite viruses c. Viroids d. Virions

a. Prions

Enveloped viruses are usually released from the host cell by Multiple Choice a. budding. b. lysis of the host cell. c. endocytosis. d. phagocytosis.

a. budding

The provirus state exists when Multiple Choice a. double-stranded viral DNA is integrated into host cell chromosome. b. single-stranded viral RNA is integrated into host cell chromosome. c. double-stranded viral RNA is integrated into host cell chromosome. d. single-stranded RNA is present as a plasmid in the host cell. e. double-stranded DNA is present as a plasmid in the host cell.

a. double-stranded viral DNA is integrated into host cell chromosome.

In phage replication Multiple Choice a. only the phage nucleic acid enters the bacterial cell. b. the whole phage particle enters the cell and the protein outer coat is removed. c. multiple phage particles enter the same host bacterial cell at the same time. d. only the phage protein enters the bacterial cell.Incorrect

a. only the phage nucleic acid enters the bacterial cell.

A prophage is Multiple Choice a. phage DNA integrated into host cell genome. b. phage DNA being actively expressed. c. phage protein left outside the bacterium. d. toxic to the host bacterial cell.

a. phage DNA integrated into host cell genome.

Feline leukemia virus may be lethal to cats but does not infect humans. This is a reflection of Multiple Choice a. the host range of feline leukemia virus. b. the fact that viruses are not pathogenic to humans. c. the fact that cats have long been domesticated by humans, rendering humans immune to infection d. the viruses lysogenic cycle.

a. the host range of feline leukemia virus.

Which of the following does NOT represent an event in bacteriophage multiplication? Multiple Choice a. Releases from host cell by cell lysis b. Uncoating of the nucleic acid in cytoplasm c. Destruction of the cell is immediate when released d. Precise attachment to the host cell e. Synthesis and assembly occur in the cytoplasm

b. Uncoating of the nucleic acid in cytoplasm

Which step is present in bacteriophage multiplication but not in multiplication of an animal virus? Multiple Choice a. New viral particles are released from the host cell by lysis. b. Viral genetic material is injected into the host cell. c. The viral genome is replicated by the host cell. d. Assembly of new viral particles occurs in the cytoplasm. e. New viruses exit the cell by budding from the cell membrane.

b. Viral genetic material is injected into the host cell.

Retroviruses have Multiple Choice a. one copy of single-stranded RNA. b. two copies of single-stranded RNA. c. tone copy of double-stranded RNA. d. two copies of single-stranded DNA.

b. two copies of single-stranded RNA.

Which of the following can cause a phage in the lysogenic stage to revert to the lytic stage? Multiple Choice a. lack of nutrients b. ultraviolet light c. a competing phage d. darkness e. an electrical charge

b. ultraviolet light

The viral capsid Multiple Choice a. engulfs the viral spikes. b. surrounds the viral matrix protein. c. becomes completely enclosed by the region of the cell membrane into which the spikes and matrix protein are embedded. d. is dissolved.

c. becomes completely enclosed by the region of the cell membrane into which the spikes and matrix protein are embedded.

A positive (+) strand of RNA Multiple Choice a. cannot function directly as mRNA. b. makes a minus (-) strand of RNA which can then act as mRNA. c. can directly act as mRNA. d. must be double stranded.

c. can directly act as mRNA.

The negative (-) sense strand of RNA Multiple Choice a. plays no role. b. makes RNA replicase. c. is used to synthesize more (+) strands. d. acts as mRNA to make viral proteins.

c. is used to synthesize more (+) strands.

In the attachment step of phage replication Multiple Choice a. attachment is nonspecific. b. carbohydrate receptors in the phage tail attach to specific receptors on the bacterial cell wall. c. protein fibers in the phage tail attach to specific receptors on the bacterial cell wall. d. phage DNA exits the protein coat and attaches to receptors on the bacterium.

c. protein fibers in the phage tail attach to specific receptors on the bacterial cell wall.

What data or achievement was instrumental to the initial characterization of viruses? Multiple Choice a. the development of the light microscope to visualize microscopic organisms b. the use of defined media to grow animal viruses c. the discovery that infectious fluid remained infectious even when passed through a filter designed to trap bacteria d. the sequencing of viral DNA in the late 1800s

c. the discovery that infectious fluid remained infectious even when passed through a filter designed to trap bacteria

In the replication of the positive (+) sense strand of lytic RNA phage, in order to make more positive (+) strands Multiple Choice a. the (+) RNA strand must code for the synthesis of RNA polymerase (replicase). b. the RNA replicase uses the (+) sense RNA as a template to make (-) strand RNA. c. the (-) sense strand RNA is used to make more (+) strands. d. All of these choices are correct.

d. All of these choices are correct.

Which of the following terms is associated with the release of nonenveloped or complex viruses from the host cell? Multiple Choice a. budding b. exocytosis c. endocytosis d. lysis e. phagocytosis

d. lysis

Together, the capsid and the nucleic acid are referred to as the __________. Multiple Choice a. spike b. envelope c. genome d. nucleocapsid

d. nucleocapsid

If the DNA of the provirus is transcribed Multiple Choice a. several single mRNA strands are produced. b. a plasmid is made. c. the provirus detaches and becomes lytic. d. one long polygenic mRNA is produced.

d. one long polygenic mRNA is produced.

In the lytic cycle of phage replication Multiple Choice a. phage genes integrate into the host cell genome and are not expressed. b. phage genes exist as prophage. c. phage DNA remains inside the protein coat. d. phage nucleic acid is replicated and phage genes are expressed, making new phage protein and lysing the host cell.

d. phage nucleic acid is replicated and phage genes are expressed, making new phage protein and lysing the host cell.

The stage of T4 replication that involves the copying of the phage DNA and the synthesis of various phage proteins is the Multiple Choice a. assembly stage. b. attachment stage. c. lysis stage. d. transcription stage. e. penetration stage.

d. transcription stage.

The first event to occur is Multiple Choice a. inside of the host cell membrane becomes coated with viral matrix protein. b. viral capsid becomes enclosed by cell membrane. c. inside of host cell membrane becomes coated with capsid. d. viral spike proteins are inserted into host cell membrane

d. viral spike proteins are inserted into host cell membrane

The stage of T4 replication that involves the injection of phage DNA is the Multiple Choice a. assembly stage. b. attachment stage. c. lysis stage. d. transcription stage. e. penetration stage.

e. penetration stage.