Chapter 13 - Viruses

True/False: Prion replication depends on the presence of a protease.

False

Which of the following statements about specialized transduction is TRUE? A. It is a result of a packaging error B. Specific DNA is transferred C. The host cell is killed D. Plasmid DNA is always transferred E. It transfers RNA from one cell to another

B. Specific DNA is transferred

Why is it that abnormal forms of prion self-proteins can accumulate over time in the central nervous system, leading to disease? A. The abnormal forms are hidden within the meninges. B. The abnormal forms actively degrade normal host cell proteases. C. The abnormal forms are resistant to normal cellular protease degradation. D. There are no clearance mechanisms in place in the central nervous system. E. Their buildup is so rapid that normal clearance mechanisms can't keep up.

C. The abnormal forms are resistant to normal cellular protease degradation.

Which form of transduction results from excision errors during the transition from a lysogenic to lytic cycle? A. Generalized B. Marginalized C. Specialized D. Immortalized E. Compartmentalized

C. Specialized

Which of the following are viral protein components that attach to specific receptors on host cells? A. Capsomeres B. Matrix C. Spikes D. Tail fibers

C. Spikes D. Tail fibers

Rank the following by size, from smallest to largest, starting with the smallest at the top. A. Bacteria B. Human Cells C. Viruses

C. Viruses A. Bacteria B. Human Cells

Filamentous phages: A. infect animal and bacterial cells B. cause their host cells to grow more quickly C. are extruded from the host cell D. undergo assembly in the cytoplasm E. degrade the host cells' DNA

C. are extruded from the host cell

All phages must be able to: I. inject their nucleic acid into a host cell II. kill the host cell III. multiply in the absence of living bacteria IV. lyse the host cell V. have their nucleic acid replicate in the host cell A. I, II B. II, III C. III, IV D. IV, V E. I, V

E. I, V

Animal viruses are divided into a number of families whose names end in A. -virus B. -viridae C. -viscous D. -eieio E. -virum.

B. -viridae

Which of the following descriptions fits the definition of a viroid? A. Nucleic acid material surrounded by a phospholipid membrane B. Nucleic acid material surrounded by a protein coat C. Nucleic acid material surrounded by a phospholipid membrane and cell wall D. Single-stranded RNA molecules forming a closed ring E. Protein only, no nucleic acid or lipid components

D. Single-stranded RNA molecules forming a closed ring

Temperate phages can do all of the following, except: A. lyse their host cells B. change the properties of their hosts C. integrate their DNA into the host DNA D. bud from their host cells E. becomes prophages

D. bud from their host cells

The viral genome is protected from the environment by a protein shell called the _____________. A. polynucleotide B. glycocalyx C. envelope D. capsid

D. capsid

True/False: Viruses that cause acute infection result in productive infections.

True

True/False: The host range of a virus depends on the presence of host receptor molecules.

True

Which of the following statements about human papilloma virus (HPV) are TRUE? (NOTE: Please change all question marks to checkmarks for correct answers or empty boxes for incorrect answers.) A. HPV is more resistant to disinfectants than is herpes simplex virus. B. HPV may be carcinogenic. C. HPV is easily destroyed by disinfectants compared with herpes simplex virus. D. A person infected with HPV strain 16 will definitely develop cancer. E. A vaccine that protects against some dangerous strains of HPV is available.

A, B

Select the TRUE statements regarding reverse-transcribing viruses. (NOTE: Please change all question marks to checkmarks for correct answers or empty boxes for incorrect answers.) A. They have a unique enzyme called reverse transcriptase. B. Their replication strategy goes against the central dogma of genetics. C. They have both RNA and DNA. D. They exhibit high mutation rates in their genomes. E. They infect primarily bacteria.

A, B, D

Which of the following statements about plant virus transmission are TRUE? (NOTE: Please change all question marks to checkmarks for correct answers or empty boxes for incorrect answers.) A. Plant viruses enter their host through wounds. B. Grafted plants may be at risk of virus infection. C. An animal infected with a virus can transmit that virus to a plant. D. An insect may transmit viruses between plants. E. Parasitic fungi may transmit plant viruses

A, B, D, E

Bacteriophage MS2 is an icosahedral, (+) sense, single-stranded RNA phage. It infects E. coli and other members of the Enterobacteriaceae. It only infects strains of these bacteria that have produced a sex pilus. Based on the information given, which of the following are true about MS2? A. The bacterial receptor for MS2 is on the F (sex) pilus. B. MS2 is a virulent phage. C. MS2 is a temperate phage. D. The phage carries a replicase. E.MS2 carries a DNA polymerase. F. MS2 can only infect F+ bacteria.

A, B, D, F

Streptococcus pneumoniae is a bacterial pathogen that can cause pneumonia. Laboratory studies of various subtypes of this organism by The Rockefeller University scientists revealed that some of them produced colonies of different opacity (cloudiness). They found that compared with bacteria from opaque colonies, bacteria from more transparent colonies were found to grow more quickly and to adhere more efficiently to bronchial cells in culture. They also found that the bacteria from transparent colonies contained a phage strain called MM1-1998. Based on this information, which of the following statements are TRUE? A. S. pneumoniae forming transparent colonies are lysogens. B. S. pneumoniae bacteria containing MM1-1998 have a competitive advantage. C. MM1-1998 affected genotype but not phenotype of the S. pneumoniae. D. Lysogenized S. pneumoniae is immune to infection by other strains of MM1. E. Providing that the culture conditions of the S. pneumoniae are unchanged, subsequent generations of this bacterium will also exhibit change in transparency and growth ability

A, B, E

Please select the methods that are used to cultivate animal viruses. (NOTE: Please change all question marks to checkmarks for correct answers or empty boxes for incorrect answers.) A. Use of cell culture techniques. B. Use of enriched agar media. C. Use of animal inoculation. D. Inoculation of embryonated eggs. E. Use of enriched broth media.

A, C, D

You discover a new medication that prevents the activity of RNA-dependent RNA polymerase. Which of the following will be affected by this medication? (NOTE: Please change all question marks to checkmarks for correct answers or empty boxes for incorrect answers.) A. Ebola virus B. Herpes zoster virus C. Human immunodeficiency virus D. T4 phages E. Polioviruses

A, E

Which of the following is an example of lysogenic conversion? A. A lysogen that acquires new characteristics as a result of the prophage. B. A temperate phage that loses the ability to synthesize a repressor. C. A temperate phage that loses the ability to recognize a repressor. D. A lysogen in which the prophage excises from the chromosome and begins the lytic cycle. E. All of the answer choices are correct.

A. A lysogen that acquires new characteristics as a result of the prophage.

Which of the following is required for prion replication? A. Abnormal prion protein B. DNA-dependent DNA polymerase C. DNA-dependent RNA polymerase D. RNA-dependent RNA polymerase E. All choices are correct.

A. Abnormal prion protein

Which of the following descriptions fits a chronic viral infection? A. Characterized by continuous production of low levels of viral particles, potentially even in the absence of active symptoms of disease. The organism is usually still highly infectious during this time. B. Strong viral replication causing lysis of host cells. This can lead to a disease state shortly after infection, which is steadily eliminated by the host's immune responses. Long-term immunity is usually present after the infection is cleared. C. Long periods of time with essentially zero viral replication, punctuated by outbreaks of active replication and disease manifestation. Infected individuals are largely non-infectious between outbreak periods.

A. Characterized by continuous production of low levels of viral particles, potentially even in the absence of active symptoms of disease. The organism is usually still highly infectious during this time.

Acute infections of animals: I. are a result of productive infection II. generally lead to long-lasting immunity III. result from integration of viral nucleic acid Into the host IV. are usually followed by chronic infections V. often lead to tumor formation A. I, II B. II, III C. III, IV D. IV, V E. I, V

A. I, II

Which of the following describes a latent viral infection? A. Long periods of time with essentially zero viral replication, punctuated by outbreaks of active replication and disease manifestation. Infected individuals are largely non-infectious between outbreak periods. B. Characterized by continuous production of low levels of viral particles, potentially even in the absence of active symptoms of disease. The organism is usually still highly infectious during this time. C. Strong viral replication causing lysis of host cells. This can lead to a disease state shortly after infection, which is steadily eliminated by the host's immune responses. Long-term immunity is usually present after the infection is cleared.

A. Long periods of time with essentially zero viral replication, punctuated by outbreaks of active replication and disease manifestation. Infected individuals are largely non-infectious between outbreak periods.

What part of the E. coli T4 phage attaches to the host cell receptors? A. Capsid fragments around the nucleic acid. B. Protein fibers at the end of the phage tail. C. Pili of the envelope. D. Spikes of the envelope. E. Spikes of the cell wall.

B. Protein fibers at the end of the phage tail.

Which of the following about viruses/viral infections is FALSE? A. Phages often enter a cell via receptor-mediated endocytosis. B. The virus that causes genital herpes can establish a latent infection. C. The virus that causes chickenpox can establish a latent infection. D. Animal viruses often enter a cell via receptor-mediated endocytosis. E. Viruses are generally not considered to be "alive."

A. Phages often enter a cell via receptor-mediated endocytosis.

Why do animal viruses have envelopes and phages rarely do? A. Since bacteria don't have cell membranes, the bacterial viruses (phages) don't pick them up when they leave the target cells. B. Phages acquire an outer surrounding that is a part of the cell wall of the bacterium they were created in, rather than an outer surrounding of plasma membrane. C. Animal viruses will often use the envelope in order to fuse with the plasma membrane of a new target cell, gaining entry into the cytoplasm. D. Animal viruses build the envelope inside of the target cell as they are being replicated, but before the cell breaks open and releases them into the extracellular environment. The envelope is a remnant of this building process. E. This is a trick question. Plenty of bacteriophages have envelopes that they acquire when they bud through the lipopolysaccharide layer of the bacterial host.

A. Since bacteria don't have cell membranes, the bacterial viruses (phages) don't pick them up when they leave the target cells.

A bacterium being examined in a microbiology laboratory is found to be lysogenized by phage A. Which of the following statements is TRUE? A. The bacterium exhibits a new genotype but may not exhibit a new phenotype. B. The bacterium exhibits a new genotype and also a new phenotype. C. The bacterium is now called a lysogenic transducing particle. D. The bacterium exhibits a new phenotype but may not exhibit a new genotype. E. The bacterium is immune to reinfection by phage A and also to infection by phage B.

A. The bacterium exhibits a new genotype but may not exhibit a new phenotype.

Please choose the statement that best describes the role of viral surface proteins or spikes. A. Viral spikes provide means of attachment to host cell surface. B. Viral spikes allow viruses to bind to each other. C. Viral spikes enable replication of the viral nucleic acid. D. Viral spikes provide means for viruses to exchange nucleic acid. E. Viral spikes inject viral nucleic acid into host cell.

A. Viral spikes provide means of attachment to host cell surface.

The tail fibers on phages are associated with: A. attachment B. penetration C. transcription of phage DNA D. assembly of virus E. lysis of the host

A. attachment

Determining viral titers of both phage and animal viruses frequently involves: A. plaque formation B. quantal assays C. hemagglutination D. determining the ID50 E. counting of virions by microscopy

A. plaque formation

Viroids characteristically are composed of A. ssRNA B. dsRNA C. ssDNA D. dsDNA E. protein only

A. ssRNA

The integration of phage DNA into the bacterial chromosome occurs because of A. the phage's ability to synthesize an enzyme that integrates its DNA into the host's chromosome. B. the phage's ability to synthesize enzymes that allow it to enter the bacterium. C. similarity in RNA nucleotides in both the phage and the bacterial host. D. the similarity in enzyme metabolism in the phage and the bacterial cell. E. the phage's ability to synthesize enzymes to enter the bacterium AND similar RNA nucleotides in both.

A. the phage's ability to synthesize an enzyme that integrates its DNA into the host's chromosome.

Which of the following are TRUE regarding cultivation of viruses? (NOTE: Please change all question marks to checkmarks for correct answers or empty boxes for incorrect answers.) A. Poliovirus can be cultivated on a bacterial lawn. B. Animal viruses can be cultivated in either cancer cell lines or primary cell cultures. C. Tobacco mosaic virus can be cultivated in embryonated eggs. D. Some orthomyxoviruses can be cultivated in embryonated eggs. E. Some animal viruses can be identified by the cytopathic effects they have on host cells.

B, D, E

Explain why HIV becomes resistant so quickly when a single drug is used therapeutically. A. The virus is an RNA genome virus. By using host RNA polymerase to directly copy the genome to make more virus particles, there's no proofreading capability. This leads to a high rate of mutation of the viral genome and increased chance for drug resistance. B. HIV uses reverse transcriptase to make a cDNA version of its RNA genome. This polymerase is "'sloppy," with a high rate of error and lack of a proofreading capability. This leads to a high rate of mutation of the viral genome and increased chance for drug resistance. C. HIV synthesizes a protein enzyme that directly cleaves anti-HIV drugs, giving it a characteristically high rate of resistance to a single drug type. D. HIV is constantly changing its genetic structure by swapping genetic elements with other virus strains. This leads to a high rate of mutation of the viral genome and increased chance for drug resistance. E. Like bacteria, HIV undergoes spontaneous mutation in the presence of antibiotics, so multiple medications are used simultaneously to reduce the chance of this happening.

B. HIV uses reverse transcriptase to make a cDNA version of its RNA genome. This polymerase is "'sloppy," with a high rate of error and lack of a proofreading capability. This leads to a high rate of mutation of the viral genome and increased chance for drug resistance.

An antibiotic is added to a culture of E. coli, resulting in death of the cells. Bacteriophages are then added. Would the phages replicate in the E. coli cells? Why or why not? A. Yes, because the cellular machinery of the bacteria is most likely still active. The bacteriophages could use that machinery to replicate new virus particles. B. No, because the bacteriophages would depend too much on having the active machinery of a living host cell for replication. C. Yes, because bacteriophages are capable of reanimating dead cells to force them to produce more virus particles. D. No, because entry of the bacteriophages into the target cell is dependent on the cell being alive to conduct endocytosis of the virus. E. No, because dead E. coli cells do not have any receptors on their cell walls to which the bacteriophages can attach for entry into the host cell by fusion.

B. No, because the bacteriophages would depend too much on having the active machinery of a living host cell for replication.

A consequence of the temperate life cycle is lysogenic conversion. What does this term mean? A. When the virus converts the bacterial cell into the lysogenic state to carry the viral genome long-term. B. When a bacterial cell starts to produce a new phage protein (e.g., diphtheria toxin) after the viral genome inserts into the host genome. C. When a bacterial cell becomes dormant because of the presence of the viral genome. D. When one bacterial species is converted into another species by the virus. E. When all biochemical processes in the lysogenized cell are converted into mechanisms of producing new viral particles.

B. When a bacterial cell starts to produce a new phage protein (e.g., diphtheria toxin) after the viral genome inserts into the host genome.

Influenza viruses bud from the host cell. Based on this information, the viruses most likely: A. have an RNA genome B. are enveloped C. have a latent state D. are non-enveloped E. form a pro virus F. have a DNA genome

B. are enveloped

The correct order for the stages of a phage infection is A. penetration, transcription, attachment, replication of nucleic acid and protein, assembly, release. B. attachment, penetration, transcription, replication of nucleic acid and protein, assembly, release. C. attachment, replication of nucleic acid and protein, penetration, transcription, assembly, release. D. transcription, attachment, replication of nucleic acid and protein, assembly, penetration, release. E. attachment, replication of nucleic acid and protein, assembly, penetration, transcription, release.

B. attachment, penetration, transcription, replication of nucleic acid and protein, assembly, release.

The activation of the SOS system in a bacterium infected with a prophage results in A. destruction of certain bacterial genes AND destruction of the viral repressor through host protease activity. B. destruction of the viral repressor through host protease activity AND lysis of the bacterial cell. C. destruction of the viral repressor through host protease activity AND mutation of the DNA D. lysis of the bacterial cell, destruction of the viral genes, AND mutation of the DNA. E. destruction of certain bacterial genes AND lysis of the bacterial cell.

B. destruction of the viral repressor through host protease activity AND lysis of the bacterial cell.

Viral genomes can be ________________. A. single-stranded only B. either single-stranded or double-stranded C. double-stranded DNA or single-stranded RNA D. double stranded only

B. either single-stranded or double-stranded

Using phages to treat a bacterial infection is an interesting idea because A. a single type of phage can destroy a wide range of strains of the same pathogen. B. of the increasing problem of antibiotic resistance in pathogens. C. lysed bacteria pose no threat to a person's health. D. a single phage can be genetically engineered to infect many different species of bacteria. E. of the increasing problem of antibiotic resistance in people.

B. of the increasing problem of antibiotic resistance in pathogens.

During attachment of phage to E. coli, the phage A. actively seeks out the bacteria AND attaches to proteins or carbohydrates on the bacterial surface. B. randomly bumps into the bacteria AND attaches to proteins or carbohydrates on the bacterial surface. C. randomly bumps into the bacteria AND attaches to the bacterial RNA. D. randomly bumps into the bacteria AND attaches to the bacterial DNA. E. actively seeks out the bacteria AND attaches to the bacterial DNA.

B. randomly bumps into the bacteria AND attaches to proteins or carbohydrates on the bacterial surface.

A key feature of all viral infections is the A. integration of viral DNA into host DNA B. separation of viral nucleic acid from the capsid. C. disintegration of host DNA. D. addition of a lipid membrane to the virus. E. lysis of the host cell.

B. separation of viral nucleic acid from the capsid.

Some phages are medically important for all of the following reasons EXCEPT: A. they can destroy bacterial cells B. they also infect eukaryotic cells C. they serve as a model for general viral replication cycles D. their genome may encode a toxin

B. they also infect eukaryotic cells

Select the ways that plant viruses can infect plants. (NOTE: Please change all question marks to checkmarks for correct answers or empty boxes for incorrect answers.) A. By direct contact with specific receptors on plant cell cytoplasmic membranes. B. By contact with intact and undisturbed plant cell wall structures. C. By contaminated insects feeding on plant cells and disrupting the cell wall. D. By soil that was previously used to grow infected plants. E. Through grafting infected plant tissue onto healthy tissue.

C, D, E

Select the possible hosts of prions. (NOTE: Please change all question marks to checkmarks for correct answers or empty boxes for incorrect answers.) A. Plants B. Bacteria C. Humans D. Cattle E. Sheep F. Goats G. Deer H. Elk

C, D, E, F, G, H

Immunity to superinfection (infection of a cell at a later time with a second, identical bacteriophage) is a consequence of lysogeny. Why does this occur? A. The first virus seeks out and destroys the second competing virus. B. A repressor produced by the first virus will activate the lytic cycle of the second virus. C. A repressor produced by the first virus will actively suppress the lytic cycle of the second virus. D. The first virus is suppressing all of the biochemical activity of the cell. Therefore, the second virus can't produce any new viral particles. E. All of the resources in the cell are in use by the first virus, so there's nothing left for the second virus to use.

C. A repressor produced by the first virus will actively suppress the lytic cycle of the second virus.

Which of the following contains only one type of macromolecule? I. RNA viruses II. DNA viruses III. Prions IV. Viroids V. RNA and DNA viruses A. I, II, III, IV, and V B. II and III C. III and IV D. I, III, V E. I and IV

C. III and IV

Which of following about classifying viruses is FALSE? A. An online database classifying viruses is kept by the ICTV (International Committee on Taxonomy of Viruses) B. Viruses can be classified based on different viral characteristics C. It is not as important as classifying organisms since they are not living entities D. It provides a useful way to identify and study viruses

C. It is not as important as classifying organisms since they are not living entities

Expression of viral oncogenes in infected animal cells: A. exert their influence in an undetermined manner B. checks the activity of proto-oncogenes and prevents tumor formation C. can mimic proto-oncogenes, causing imbalance in cell cycle control towards unchecked proliferation, leading to tumor formation D. can mimic tumor suppressor genes, imbalancing cell cycle control towards unchecked proliferation, leading to tumor formation E. checks the activity of tumor suppressor gene products, preventing tumor formation

C. can mimic proto-oncogenes, causing imbalance in cell cycle control towards unchecked proliferation, leading to tumor formation

The common species name of the virus is frequently based on the A. presence or absence of a nuclear membrane B. type of nucleic acid it contains C. disease the virus causes D. geographic area it is found E. shape of the viral nucleocapsid

C. disease the virus causes

When a non-enveloped animal virus adsorbs to the host cell with its protein spikes, the virions are taken into the cell by the process of A. penetration B. production C. endocytosis D. fusion E. budding

C. endocytosis

Cells infected with animal viruses lyse because A. the release of the virions depletes the cell of energy B. the virus releases enzymes that lyse the cell C. functions necessary for cell survival are not carried out and the cell dies D. the virus RNA and cellular protein interact to kill the cell E. the viruses release lysozyme which destroys the host cell wall

C. functions necessary for cell survival are not carried out and the cell dies

Normal tissue taken from animals and prepared immediately as a medium for viral growth is termed a(n) A. advantageous group B. monolayer culture C. primary culture D. plaque E. virus culture.

C. primary culture

Capsids are composed of: A. DNA B. RNA C. protein D. lipids E. polysaccharides

C. protein

Classification of viruses is based on all of the following, except: A. type of nucleic acid B. shape of virus C. size of virus D. host infected E. strandedness of nucleic acid

C. size of virus

Reverse transcriptase synthesizes A. viral protein from viral RNA B. (+) RNA from (-) RNA C. viral DNA from viral RNA D. (+) DNA from (-) RNA E. (+) RNA from protein.

C. viral DNA from viral RNA

Which of the following is used to classify viruses? I. Nucleic acid II. Shape III. Size IV. Host range V. Biochemical tests A. I only B. I and II C. I and IV D. I, II, III, and IV E. All of these

D. I, II, III, and IV

After beta phage infects Corynebacterium diphtheriae and integrates its DNA into the host genome, the bacterium is capable of causing the disease diphtheria. Which term best describes this phenomenon? A. Productive infection B. Lytic conversion C. Lytic cycle D. Lysogenic conversion E. Provirus F. Lysogeny

D. Lysogenic conversion

Viruses with which characteristic would be expected to have a higher mutation rate? A. Genome containing both DNA and RNA B. Enveloped virus C. DNA genome D. RNA genome E. Non-enveloped viruses

D. RNA genome

In a quantal assay, animal viruses are quantified by: A. administering several dilutions of a virus preparations to batches of bacteria, then observing plaque formation on growth plates B. utilizing a quantal microscope for direct counting methods C. administering several dilutions of a virus preparation to a number of animals, cells, or chick embryos, then determining the dilution that infected/killed 75% of the group D. administering several dilutions of a virus preparation to a number of animals, cells, or chick embryos, then determining the dilution that infected/killed 50% of the group E. mixing virus preparations with red blood cells and determining a dilution where hemagglutination stops

D. administering several dilutions of a virus preparation to a number of animals, cells, or chick embryos, then determining the dilution that infected/killed 50% of the group

Prions: A. contain only nucleic acid without a protein coat B. replicate like HIV C. integrate their nucleic acid into the host genome D. causes diseases of humans E. cause diseases of plants

D. causes diseases of humans

In virology, a plaque is a(n): A. form of lysogenic conversion B. virus particle that carries replicase C. hardened area with accumulation of capsids D. clearing in a lawn of bacteria

D. clearing in a lawn of bacteria

Influenza vaccines must be changed yearly because the amino acid sequence of the viral proteins changes gradually over time. Based on this information, which is the most logical conclusion? The influenza virus: A. is enveloped B. is non-enveloped C. has a DNA genome D. has an RNA genome E. causes a persistent infection

D. has an RNA genome

A virus usually infects only certain types of cells due to: A. the presence or absence of a cell wall on the host cell B. particular genes that it shares with the infected cell C. differences in size between the virus and the host cell D. interactions between viral and cellular surface molecules E. the speed with which it can enter these cells.

D. interactions between viral and cellular surface molecules

In enveloped viruses, sandwiched between the nucleocapsid and the envelope is the _______________. A. exoskeleton B. exocapsid C. endocapsid D. matrix protein E. nucleocapsid

D. matrix protein

In the region of budding, the inside of the cytoplasmic membrane becomes coated with: A. enzymes B. carbohydrates C. steroids D. matrix proteins E. phospholipids.

D. matrix proteins

All of the following could serve as receptors for phage attachment EXCEPT: A. flagellum B. pilus C. cell wall D. ribosomes

D. ribosomes

Once inside the host cell, phage DNA A. is replicated B. is transcribed C. may get degraded by bacterial nucleases D. may integrate into the host chromosome E. All of the choices are correct.

E. All of the choices are correct.

Which is true of lysogenized cells? A. They are immune to any further infection by any virus. B. They are immune to infection by the same virus. C. They may have new properties AND they respond to infection with the SOS response. D. They respond to infection with the SOS response. E. They are immune to infection by the same virus AND may have new properties.

E. They are immune to infection by the same virus AND may have new properties.

Phage-encoded proteins are A. coded for by host DNA B. coded for by phage DNA C. proteins normally present in the uninfected cell D. early proteins E. coded for by phage DNA AND early proteins.

E. coded for by phage DNA AND early proteins.

True/False: Completed filamentous phages are often found in the cytoplasm of infected bacteria.

False

True/False: Plant viruses and animal viruses enter their hosts cells after binding to receptors.

False

True/False: There are no plant viruses that can be transmitted through virally contaminated seeds or pollen.

False

True/False: Bacteriophages, unlike animal viruses, often have special viral-specific enzymes carried in the capsid, which enter the host cell at the same time as the nucleic acid.

False