CH26: Viruses study questions

Select all that apply Which of the following are reasons why classifying viruses by disease they cause can be impractical? -The same disease can be caused by many different viruses. -Some viruses do not appear to cause any disease. -Some viruses have a very narrow host range. -Some viruses can only infect certain types of cells. -Some viruses can cause different disease in different context.

-The same disease can be caused by many different viruses. -Some viruses do not appear to cause any disease. -Some viruses can cause different disease in different context.

In the Baltimore classification of viruses, there are _____1_____ groups of viruses and every known virus can be placed in only one such group based on the way it _____2_____ its genome

1:7 or seven 2:replicates, duplicates, copies, or makes copies of

The classification of viruses based on genome replication is known as the _____1_____ classification after the scientist that first proposed it.

1:BALTIMORE

Viruses that contain _____1_____ as their genetic material are often assigned to species group; the same is not true of viruses with _____2_____ as their genetic material.

1:DNA 2:RNA

Viral genomes may be composed of _____1_____ or _____2_____ and may be ____3______ -stranded or ____4______ -stranded.

1:DNA 2:RNA 3:SINGLE 4:DOUBLE

A viral capsid with an overall _____1_____ structure has a rodlike or threadlike appearance.

1:HELICAL

Most viruses have a capsid that is ____1_____ or _____2_____ in terms of its basic structure and symmetry.

1:HELICAL 2:ICOSAHEDRAL

A virus' _____1_____ _____2_____ refers to the suitable cells they can infect.

1:HOST 2:RANGE

Viruses can infect all types of organism that have been investigated for their presence, but each type of virus has a relatively narrow ______1______ ______2______ .

1:HOST 2:RANGE

_____1_____ involves isolating DNA from an environmental sample, sequencing it, and comparing it to known sequences in DNA databases.

1:METAGENOMICS

Click and drag on elements in order Rank the following cells and particles in order according to size, with the smallest at the top and largest at the bottom. protein/ T2 bacteriophage/ E. coli bacterium/ Eukaryotic cell/ Influenza virus

1:PROTEIN 2:T2 BACTERIOPHAGE 3:INFLUENZA VIRUS 4:E. COLI BACTERIUM 5:EUKARYOTIC CELL

Viruses are nonliving particles with a genome made of DNA or ____1______, surrounded by a shell (capsid) made of ____2______.

1:RNA 2:PROTEINS

Viruses with a two-tailed structure, with a bottle shaped structure, and with a spindle-shaped structure have all been observed in A:Archaea B:Bacteria C:Plants D:Animals

A:Archaea

Which of the following viruses uses the cellular machinery of a bacterium for its own replication? A:Bacteriophage B:Prophage C:Retrovirus D:Lysogen

A:Bacteriophage

Why is it difficult to classify influenza viruses based on their host? A:Because there are four types of influenza viruses that can infect many different hosts (humans, birds, pigs, dogs, cats) B:Because some influenza viruses do not appear to cause disease in humans. C:Because different influenza viruses infect different tissues in different hosts.

A:Because there are four types of influenza viruses that can infect many different hosts (humans, birds, pigs, dogs, cats)

Which of the following statements most accurately describes the host specificity of viruses? A:Viruses infect all types of organisms, but individual viruses are very limited in the species and cell types they can infect. B:Viruses infect all types of organisms, and individual viruses can infect all species and cell types. C:Viruses infect only bacteria and animals, but individual viruses can infect all species and cell types. D:Viruses only infect bacteria and animals, and individual viruses are very limited in the species and cell types they can infect.

A:Viruses infect all types of organisms, but individual viruses are very limited in the species and cell types they can infect.

Viruses are A:obligate intracellular parasites B:facultative extracellular parasites C:obligate extracellular parasites D:facultative intracellular parasites

A:obligate intracellular parasites

Select all that apply Choose all the conventional systematic groups that are also used to classify viruses. A:Class B:Family C:Domain D:Kingdom E:Order F:Genus

B:Family E:Order F:Genus

How do viruses replicate? A:Genetic material is exchanged among two virions, undergoes recombination, and is packaged in capsids synthesized by the parents. B:Host cells' transcription and translation systems are used to replicate the genome and create capsid proteins. C:Inside the host cell, the genome is replicated using viral DNA polymerase, after which the capsids undergo binary fission. D:Inside a host cell, the genome is replicated using viral DNA polymerase and capsid proteins are synthesized using viral enzymes.

B:Host cells' transcription and translation systems are used to replicate the genome and create capsid proteins.

Which of the following are the two types of structure typical of most viral capsids? A:Polymorphic or icosahedral B:Icosahedral or helical C:Icosahedral or binal D:Binal or polymorphic E:Helical or polymorphic

B:Icosahedral or helical

Which of the following statements best describes viral genomes? A:Although they may be composed of DNA or RNA, the viral genome structure is the same among all viruses. B:They may be circular or linear, single-stranded or double-stranded, and composed of DNA or RNA. C:All viral genomes are linear, double-stranded, and composed of DNA. D:All viral genomes are composed of DNA, but they may be circular or linear and single-stranded or double-stranded.

B:They may be circular or linear, single-stranded or double-stranded, and composed of DNA or RNA.

The number of species and cell types that a virus can infect refers to a virus' A:host limit B:host range C:host species

B:host range

In order to study viruses in the environment, scientists isolate nucleic acids from an environmental sample, sequence them, and use computers to assemble genomes and compare them to known sequences in databases. This approach is known as _______. A:metagenomics B:metagenomics C:viral sequencing D:environmental genomics

B:metagenomics

Which of the following describes a virus? A:A small parasitic cell that has lost some of its internal structures B:A small biological particle that is comprised almost entirely of protein C:A small biological particle comprised of nucleic acid enclosed in a protein coat D:A small biological particle that is comprised entirely of single-stranded, circular RNA

C:A small biological particle comprised of nucleic acid enclosed in a protein coat

Why is it difficult to classify influenza viruses based on their host? A:Because some influenza viruses do not appear to cause disease in humans. B:Because different influenza viruses infect different tissues in different hosts. C:Because there are four types of influenza viruses that can infect many different hosts (humans, birds, pigs, dogs, cats)

C:Because there are four types of influenza viruses that can infect many different hosts (humans, birds, pigs, dogs, cats)

A helical capsid has a shape that resembles which of the following? A:Soccer ball B:Head attached to a hollow tail and tail fibers C:Rod or thread D:Plate E:Pyramid

C:Rod or thread

Identify the disease agent that ranges in size from about 20-250 nm in diameter. A:Prions B:Bacterium C:Virus

C:Virus

Viruses are unable to reproduce without which of the following? A:An envelope B:Another virus C:Reverse transcriptase D:A host cell

D:A host cell

Which of the following are the two types of structure typical of most viral capsids? A:Polymorphic or icosahedral B:Binal or polymorphic C:Helical or polymorphic D:Icosahedral or binal E:Icosahedral or helical

E:Icosahedral or helical

Viruses are obligate ____________ parasites.

intracellular