Microbiology Chapter 13 Answers – Flashcards

In which of the following ways do viruses differ from bacteria?

A viruses are filterable

B viruses are obligate intracellulare parasites

C viruses don't have any nucleic acid

D viruses are not composed of cells

E viruses don't reproduce

Which of the following staements providesthe most significant support for the idea that viruses are nonliving chemicals?

A they are not composed of cells

B they are filterable 

C they cannot reproduce themselves outside a host

D they cause diseases similar to those caused by chemicals

E. they are chemically simple

Which of the following statements about spikes is false?

A they are for penetration

B they are used for absorption

C they may cause hemaggllutination

D they are found only on enveloped viruses

E they are found only on nonenveloped viruses

Which of the following is not used as a criterion to classify viruses?

A biochemical tests

B morphology

C nucleic acid

D size

E number of capsomeres

Which of the following is not a method of culturing a virus?

A in lab animals

B in culture media

C in embryonated eggs

D in cell culture

E none of the above 

Bacteriophages and animal viruses do not differ significantly in which one of the following steps?

A adsorption

B penetration'

C uncoating

D biosynthesis

E release

The definition of lysogeny is

A phage DNA is incorporated into host cell DNA

B lysis of the host cell due to a phage

C the period during replication when virions are not present

D when the burst time takes an unusully long time

E attachment of a phage to a cell

A viroid is

;

A a complete, infectious virus particle

B a nonenveloped, infectious piece of RNA

C a capsid without a nucleic acid

D a provirus

E an infectious protein

In figure 13.1 which structure is a compex virus

;

A a

B b

C c

D d

E all of the above

In figure 13.1 the structure illustrated are composed of;

A DNA

B RNA

C DNA or RNA

D capsomeres

E Capsids

;A clear area against a confluent "lawn" of bacteria is called a;

A phage

B pock

C cell lysis

D plaque

E rash

Continuous cell lines differ from primary cell llines in that

A viruses can be grown in continuous cell lines

B continuous cell lines always have to be reisolated from animal tissues.

C continuous cell lines are derived from primary cell lines

D continuous cell lines can be maintained through an indefinite number of generations.

E. Continuous cell lines are from human embryos.

Which of the following is necessary fro replication of a prion?

A DNA

B DNA polymerase

C lysozymes

D pSc

E RNA

A persistent infection is an infection in which

;

A the virus remains in equilibrium with the host without causing a disease

B viral replication is unusually slow

C the disease process occurs gradually over a long period

D host cells are graduallylysed

E host cells are transformed

Which of the following statements is false

A a prophage is phage DNA inserted into a bacterial chromosome.

B a prophage can pop out of the chromosome

C prophage genes are represented by a repressor protein coded for by the prophage.

D a prophage may result in new properties of the host cell

E the prophage makes the host cell immune to infection by other phages

Lysogeny can result in all of the following except

A innumity to reinfection by the same phage

B acquisition of new characteristics by the host cell

C immunity to reinfection by any phage

D transduction of specific genes.

E none of the above.;

Which of the following would be the first step in biosynthesis of a virus with a - strand of RNA

;

A synthesis of DNA from an RNA template

B synthesis of double stranded RNA from an RNA template

C synthesis of double stranded RNA from a DNA template

D transcription of mRNA from DNA

E synthesis of DNA from a DNA template

An infectious protein is a;

A bacteriophage

B prion

C retrovirus

D viroid

E papovavirus

An envelope is acquired during which of the following steps?

A pentration

B adsorption

C uncoating

D Biosynthesis

E release

Which of the following contributes to the difficulty in establishing etiology of cancer?

A most viral particles can infect cells without inducing cancer

B cancer may not develop until long after infection

C cancers do not seem to be contagious

D viruses are difficult to observe

E all of the above

An example of a latent viral infection is

;

A subacute sclerosing panencephalitis

B cold sores

C influenza

D smallpox

E mumps

;

The most common route of accidental AIDS transmission to health care workers is;

A mouth to mouth

B fecal oral

C needlestick

D aerosol

E environmental surface contact

;

Assume you have isolated an unknown virus. ;It is a single stranded RNA enveloped virus. ;To which group does it most likely belong?

A herpesvirus

B picornavirus

C retrovirus

D togavirus

E papovavirus

To which group does a small, nonenveloped single stranded RNA virus most likely belong?

A herpesvirus

B picornavirus

C retrovirus

D togavirus

E papovavirus

The most conclusive evidence that viruses cause cancers is provided by;

A finding oncogens in viruses

B the presence of antibodies against viruses in cancer patients

C cancer following injection of cell-free filtrates

D treating cancer with antibodies

E some liver cancer patients having hepatitis

;

Bacteriophages derive all of the following from the host cell except

A lysozymes

B tRNA

C amino acids

D nucleotides

E ATP

Generalized transduction differs from specialized transduction in that generalized transduction

A kills the host

B transfers DNA from one cell to another

C transfers specific DNA

D involves lysogeny

E lyses the host cell

Generally in a DNA containing virus infection, the host animal cell supplies all of the following except

A RNA polymerase

B nucleotides

C DNA polymerase

D tRNA

E all of the above are supplied by the host animal cell;

Pput the following in correct order for DNA virus replication:

1 maturation, 2 DNA synthesis, 3 transcription, 4 translation

A 1,2,3,4

B 2,3,4,1

C 3,4,1,2,

D 4,1,2,3

E 4, 3,2,1

A viral species is a group of viruses that

;

A have the same morphology and nucleic acid

B have the same genetic information

C infect the same cells and cause the same disease

D can't be defined

Viruses that have reverse transcriptase are in the 

A retroviridae and picornaviridae

B herpesviridae and retroviridae

C hepadnaviridae and retroviridae

D Bacteriophage families

E influenzavirus

DNa made from an RNA template will be incorporated into the virus capsid of 

A retroviridae

B herpesviridae

C hepadnaviridae

D bacteriophage families

E influenzavirus

Which of the following statements about viruses is false?

A viruses contain DNA or TNA but never both

B viruses contain a protein coat

C virues use the anabolic machinery of the cell

D viruses use their own catabolic enzymes

E viruses have genes

Approximately how many virus particles could fit along a 1-millimeter line?

A 2

B 20

C 200

D 20,000

E 2,000,000

Some viruses, such as human herpesviruses 1, infect a cell without causing symptoms; these are called

A latent viruses

B lytic viruses

C phages

D slow viruses

E unconventional viruses

Assume a patient had chickenpox (human herpesvirus 3) as a child.  Which line on the graph in figure 13.2 would show the number of viruses present in this person as a 60 year old with shingles (human herpesvirus 3)

A a 

B b

C c

D d

E e

Assume a patient has influenza.  During which time (on the graph in figure 13.2) would the patient show the symptoms of the illness.

A a

B b

C c

D d

E e 

The following steps occur during multiplication of herpes viruses.  What is the the third step?

A attachment

B biosynthesis

C penetration

D release

E uncoating

The following steps occur during multiplication of retroviruses.  What is the the fourth step?

A synthesis of +RNA

B attachment

C penetration

D release

E uncoating

Nontoxic strains of Vibrio cholerae can become toxic when they are in the human intestine with toxic strains of bacteria.  This suggests that the toxin genes are acquired by

A host enzymes

B prions

C reverse transcriptase

D transduction

E none of the above

Which of the following steps does not occur during multiplication of a picornavirus?

A synthesis of + strands of RNA

B synthesis of -strands of RNA

C synthesis of viral protiens

D synthesis of DNA.

E none of the above

Which of the following is most likely a product of an early gene?

A capsid proteins

B DNA polymerase

C envelope proteins

D spike proteins

E lysozyme

Most RNA viruses carry which of the following enzymes?

A DNA-dependent DNA polymerase

B lysozyme

C RNA dependent RNA polymerase

D reverse transcriptase

E ATP synthase

The following steps occur during biosynthesis of a +strand RNA virus.  What is the third step?

A attachment

B penetration and uncoating

C synthesis of -strand RNA

D synthesis of +strand RNA

E synthesis of viral proteins

What contributes to antigenic shift in influenza viruses?

A worldwide distribution

B segmented genome

C attachment spikes

D ease of transmission

E different subtypes