Ch.13 Viruses Viroids and Prions

Which of these factors is NOT used in classifying viruses? a) Genome b)Disease symptoms c)Host range d)Morphology

b)Disease symptoms

What is the usual size range of viruses? a)30 to 300 nanometers b)20 to 300 centimeters c)20 to 300 millimeters d)20 to 300 micrometers

a)30 to 300 nanometers

Which of the following terms are NOT correctly matched? a)Poxviridae; chickenpox b)Picornaviridae; polio c)Flaviviridae; hepatitis d)Herpesviridae; infectious mononucleosis e)Picornaviridae; common cold

a)Poxviridae; chickenpox

Some viruses have a membrane like structure on their surface, composed of lipids, proteins, and carbohydrates. This is called a(n) __________. a)envelope b)capsid c)core d)capsule

a)envelope

A double-stranded, enveloped DNA virus that contains reverse transcriptase belongs to which family? a)Picornaviridae b)Hepadnaviridae c)Poxviridae d)Retroviridae e)Rhabdoviridae

b)Hepadnaviridae explanation: Hepadnaviridae are so named because they cause hepatitis and contain DNA. Hepadnaviruses differ from other DNA viruses because they synthesize DNA by copying RNA, using viral reverse transcriptase. This DNA is the template for viral mRNA and the virus's DNA genome.

Viruses possess genetic material comprised of DNA or __________. a)guanine b)RNA c)ATP d)Plasmids e)NADPH

b)RNA

To what does the term viral species refer? a)A group of viruses sharing the same disease symptoms b)Viruses grouped according to growth on selective media c)A group of viruses sharing the same genetic information and structure d)Viruses grouped according to their susceptibility to antibiotics e)A group of viruses that are reproductively isolated

c)A group of viruses sharing the same genetic information and structure

Which of the following is NOT characteristic of viruses? a)Viruses are unaffected by antibiotics. b)Viruses have either DNA or RNA but not both. c)Viral nucleic acid is surrounded by a plasma membrane. d)Viruses lack an ATP-generating mechanism.

c)Viral nucleic acid is surrounded by a plasma membrane.

Which statement about viruses is FALSE? a)Viruses are active only when inside a cell. b)The genome of a virus can be either DNA or RNA, depending on the particular virus. c)Viruses will usually infect any available cell, regardless of the cell type. d)Viruses always have a protein coat.

c)Viruses will usually infect any available cell, regardless of the cell type. explanation: The host range of a virus is the spectrum of host cells the virus can infect. There are viruses that infect invertebrates, vertebrates, plants, protists, fungi, and bacteria. However, most viruses are able to infect specific types of cells of only one host species.

The protein coat of a virus is called the __________. a) capsomere b)viral membrane c)capsid d)envelope

c)capsid

A virus may contain any of any of the following EXCEPT (a) __________. a)spike proteins b)capsid proteins c)ribosomes d)lipid envelope e)ssRNA

c)ribosomes

Members of the Adenoviridae cause __________. a)hepatitis b)cold sores c)the common cold d)influenza e)smallpox

c)the common cold explanation: Named after adenoids, from which they were first isolated, adenoviruses cause acute respiratory diseases—the common cold.

A double-stranded, enveloped DNA virus that contains reverse transcriptase belongs to which family? a)Retroviridae b)Poxviridae c)Picornaviridae d)Hepadnaviridae e)Rhabdoviridae

d)Hepadnaviridae

Influenza viruses are classified according to their hemagglutin and __________ proteins. a)nucleic b)amphiphilic c)polymorphic d)neuraminidase e)arabinose

d)neuraminidase explanation: The subtypes of the influenza virus differ because of certain proteins on the surface of the virus (hemagglutinin [HA] and neuraminidase [NA] proteins). There are 16 different HA subtypes and 9 different NA subtypes of influenza A viruses.

The potential use of viruses that infect bacteria to treat bacterial infections in humans is known as __________. a)persistent therapy b)latent infection c)oncolytic therapy d)phage therapy

d)phage therapy

Which type of microscope is needed to view a virus in the laboratory? a)Darkfield b)Compound c)Brightfield d)Fluorescent e)Electron

e)Electron

Viruses that use RNA as a template for transcribing DNA include __________. a) Togaviridae b)Picornaviridae c)Herpesviridae d)Rhabdoviridae e)Retroviridae

e)Retroviridae