Exam Two- homework and quizzes

chapters 13. 14, 15, 16, 17

viruses possess genetic material composed of DNA or…

RNA

to what does the term viral species refer?

a group of viruses sharing the same genetic information and structure

viruses that use RNA as a template for transcribing DNA include…

retroviridae

a virus may contain any of the following EXCEPT…

ribosomes

some viruses have a membranelike structure on their surface, composed of lipids, proteins, and carbohydrates. this is called an…

envelope

the potential use of viruses that infect bacteria to treat bacterial infections in humans is known as…

phage therapy

which of these factors is NOT used in classifying viruses?

disease symptoms

which type of microscope is needed to view a virus in the laboratory?

an electron microscope

members of the Adenoviridae cause…

the common cold

which of the following terms are NOT correctly matched?

Poxviridae; chickenpox

Influenza viruses are classified according to their hemagglutin and BLANK proteins

neuraminidase

which of the following is NOT a characteristic of viruses?

viral nucleic acid is surrounded by plasma membrane

a double-stranded, enveloped DNA virus that contains reverse transcriptase belongs to which family?

Hepadnaviridae

the protein coat of a virus is called the …

capsid

which statement about viruses is FALSE?

viruses will usually infect any available cell; regardless of the cell type

What is the usual size range of viruses?

30 to 300 nanometers

which method CANNOT be used to culture viruses in a laboratory?

nutrient agar culture medium

what is the name given to the viral DNA incorporated into a lysogenic cell?

prophage

after the attachment and entry of a virus into a host cell, what is the next step in the multiplication of animal viruses?

uncoating

during BLANK, the phage remains latent

lysogeny

which of these statements is NOT true?

attachment of animal viruses to host cells is random and nonspecific

cell lines derived from transformed (cancerous) cells are called…

continuous cell lines

the toxin production by Corynebacterium diphtheria carrying a template phage is an example of…

phage conversion

which two virus families make DNA from an RNA template?

Hepadnaviridae and Retroviridae

how might a virus pick up a human oncogene?

specialized transduction

consider a virus whose genome is composed of minus (-) sense RNA (for example, the rabies virus). what would be the first step in the biosynthesis of that virus?

synthesize mRNA from the - sense RNA genome

how would you know that viruses were multiplying in a confluent lawn of E. coli on a solid culture medium?

there would be a small zone of clearing in the bacterial culture

retroviridae use an RNA-dependent DNA polymerase called BLANK to transcribe DNA from an RNA strand.

reverse transcriptase

some viruses leave a cell by pushing through the cell membrane (rather than lysing the cell). when this happens, a portion of the membrane wraps around the viral capsid, becoming the envelope. what is the name for this process?

budding

in polio virus replication, the function of the antisense (-strand) RNA is to…

serve as a template for the production of sense (+strand) RNA

which of the following is the preferred method for cultivating many animal viruses?

growing them in animal cell cultures

why may you be asked whether you are allergic to eggs before receiving a vaccination?

some viruses are grown and isolated in embryonated eggs; especially those used for vaccines.

* the egg proteins may still be present in the viral vaccine preparations

during the bacteriophage lysogenic cycle, …

phage DNA is inserted into the host chromosome

which of these processes of viral multiplication is most likely to damage the host cell?

release of nonenveloped viruses

which of these viruses can incorporate the molecule serving as mRNA into its capsid?

picornavirus

which of these enzymes is necessary for the replication of a +strand RNA virus?

RNA-dependent RNA polymerase

the following steps occur during bacteriophage replication. what is the second step?

penetration

all of the following are prion diseases EXCEPT…

Wiles-Davidoff syndrome

which of the following is NOT an oncogenic virus?

Varicellovirus

which of the following are possible strategies for treating viral infections?

* blocking viral attachment to host cell receptors
* blocking uncoating of the virus after entry
* blocking insertion of viral DNA into the host cell chromosomes
* blocking biosynthesis of viral nucleic acids

which of the following may cause a persistent viral infection?

measles virus

which of the following pairs is NOT correctly matched?

viroid; infectious DNA

shingles is a medical condition that usually occurs years after chickenpox, even though no illness is present in the intervening period of time.

* this occurs because human herpes virus-3 (HHV-3) is capable of…

latent infection

which of these viruses is known to cause a persistent viral infection?

measles virus

infectious agent known as BLANK cause Creutzfeldt-Jakob disease (CJD)

prions

which of the following is NOT an oncolytic virus?

retrovirus

prions cause disease by…

altering normal proteins

an example of a latent virus infection is…

shingles

what type of infectious agent causes potato spindle tuber disease?

viroid

which of the following body sites typically does NOT have normal microbiota?

kidney

germ-free animals often are more susceptible to infections and serious diseases than are animals with a typical complement of the normal microbiota

* based on this observation, which of the following would be an appropriate conclusion?

normal microbiota stimulate the development of the immune system

P. aeruginosa and other gram-negative bacteria tend to be difficult to control with antibiotics because of their BLANK, which carry genes that determine resistance to antibiotics.

R factors

microorganisms that typically colonize a host without causing disease are referred to as the…

normal microbiota

in the human intestinal tract, E. coli produces vitamins beneficial to the host and can inhibit pathogen growth. in turn, the bacterium is supplied with nutrients and an environment for growth.

* this symbiotic relationship between E. coli and its host is an example of …

mutualism

what is the difference between normal and transient microbiota?

normal microbiota are permanently present

which of the following is NOT an example of microbial antagonism (also known as competitive exclusion)?

microbes producing vitamins and growth factors that can be utilized by the host

BLANK pathogens are those that do not cause disease in their normal habitat but may do so in a different environment

opportunistic

which of the following is nOT necessary to satisfy Koch’s postulates?

the organism must cause disease through toxin production

which of the following is NOT a notifiable infectious disease?

pneumonia

Koch’s postulates are a set of guidelines to follow if you want to …

prove that a specific infectious disease is caused by a specific microorganism

in a healthy human, resident microorganisms would be found in all of the following areas EXCEPT the…

bloodstream

which of the following best defines the term pathology?

the structural and functional changes in an individual that are brought about by disease

women who have a healthy population of Lactobacillus spp. as part of the normal vaginal microbiota are less likely to get yeast infections

* which of the following terms is used to explain this observation?

competitive exclusion

which of the following is the third stage of a disease?

period of illness

which of the following is NOT a predisposing factor of disease?

all of the listed choices can be predisposing factors of disease

* lifestyle
* occupation
* gender
* climate

which of these diseases does not have a human reservoir?

tetanus

in order to understand the full scope of a disease, we take its occurrence into account. the BLANK of a disease is the number of people in a population who develop a disease at a specific time

prevalence

a disease that is constantly present in a population is called an…

endemic disease

the occurrence of streptococcal bronchopneumonia in an individual recovering from influenza is an example of a…

secondary infection

during the BLANK, a person recovers from a disease and the body returns to its pre-disease state

period of convalescence

the presence of bacteria in the bloodstream is referred to as…

bacteremia

\n On October 29, Barbara participated in a study group for her microbiology class. On November 1, Barbara had a “scratchy throat” when she swallowed. On November 2, Barbara had a headache, runny nose, and watery eyes. She was fully recovered on November 7. During which time was Barbara in the prodromal period?

november 1

the protection from infection received when individuals susceptible to a particular disease live in a population where many individuals are immune is referred to as…

herd immunity

which of the following is part of a plan established by the CDC, NIH, and WHO to address and prioritize issues related to EIDs?

* detect infectious pathogens, the disease they cause, and factors that influence their emergence
* expand basic and applied research on ecological and environmental factors that influence EIDs
* enhance the communication of public health information and the prompt implementation of prevention strategies regarding EIDs
* establish plans to monitor and control EIDs worldwide

an infection that does NOT cause any signs of disease is a…

subclinical infection

which one of these diseases is NOT communicable?

botulism

which of these disease stages is most likely to be altered in length if the number of infecting organisms at the start of the infection is very high?

incubation period

infections in which the pathogen is distributed throughout the body are referred to as generalized infections or…

systemic infections

attachment of DNA-containing animal virus

requires a physical and chemical interaction between the surface of the virus and host cell surface

entry and uncoating of a DNA-containing animal virus

* this process disassembles the viral capsid and releases the viral DNA
* may involve receptor-mediated endocytosis
* may involve fusion of the viral envelope with the host cell plasma membrane

biosynthesis of a DNA-containing animal virus

maturation of DNA-containing animal virus

what disease does the human herpesvirus-1 cause?

cold sores or fever blisters

a feature that may be found in viruses but never in bacteria is…

may contain an RNA genome

how do all viruses differ from bacteria

viruses are not composed of cells

the morphological types of viruses illustrated in the figure are ultimately determined by the…

nucleic acid

viruses that utilize reverse transcriptase belong to the virus families…

Hepadnaviridae and Retroviridae.

which of the following is NOT utilized to culture viruses?

culture media

Each of the following can be used for the detection and/or identification of viruses except…

fermentation tests

Lysogeny can result in all of the following EXCEPT

immunity to reinfection by any phage.

An envelope is acquired during which of the following steps?

release

Which of the following places these items in the correct order for DNA-virus replication?


1. Maturation
2. DNA synthesis
3. Transcription
4. Translation

2, 3, 4, 1

Most RNA viruses carry which of the following enzymes?

RNA- dependent RNA polymerase

oncogenic viruses

cause tumors to develop

Which of the following statements regarding latent viral infections is true?

latent infections can persist for years in an individual without causing any symptoms

a persistent infection is one in which…

the disease process occurs gradually over a long period of time

an infectious protein is a …

prion

Which of the following statements concerning prion diseases is true

normal host cellular prion proteins are converted into scrapie proteins

from which phrase is the term “prions” derived

proteinaceous infectious particles

in what year did Stanley Prusiner discover prions?

1982