question

Which of the following are double-stranded RNA virusesA) Picornaviridae
B) Coronaviridae
C) Retroviridae
D) Reoviridae
E) Rhabdoviridae

answer

D) Reoviridae

question

Which of the following RNA viruses are the smallest viral pathogens in animalsA) Picornaviridae
B) Coronaviridae
C) Paramyxoviridae
D) Arenaviridae
E) Rhinoviridae

answer

A) Picornaviridae

question

Which of the following is a family of six-pointed, star-shaped viruses that cause gastrointestinal diseasesA) Picornaviridae
B) Caliciviridae
C) Rhabdoviridae
D) Coronaviridae
E) echovirus

answer

B) Caliciviridae

question

Which of the following statements about rhinoviruses is FALSEA) They are limited to infecting the upper respiratory tract.
B) They are the only viruses that can cause a common cold.
C) They are extremely infectious.
D) They thrive at 33°C.
E) Person-to-person contact is the most common mode of transmission.

answer

B) They are the only viruses that can cause a common cold.

question

Enteroviruses gain their name from the fact that
A) they infect the gastrointestinal tract.
B) they are able to withstand the low pH of the stomach.
C) they are transmitted through the fecal-oral route.
D) they spread from the intestinal lining into the bloodstream to cause viremia.
E) they remain latent inside cells in the stomach and intestines.

answer

C) they are transmitted through the fecal-oral route.

question

Diarrhea, nausea, and vomiting are signs and symptoms associated with which of the following virusesA) coxsackie A
B) enterovirus
C) rhinovirus
D) echovirus
E) norovirus

answer

E) norovirus

question

Some patients who have suffered from polio develop symptoms 30—40 years later in the form of
A) repeated cold symptoms.
B) meningitis.
C) encephalitis.
D) crippling deterioration and dysfunction in the polio-affected muscles.
E) deterioration of the nerves that control polio-affected muscles

answer

D) crippling deterioration and dysfunction in the polio-affected muscles.

question

The type of polio that involves the infection of the brain stem and medulla is
A) asymptomatic polio.
B) postpolio syndrome.
C) bulbar poliomyelitis.
D) minor polio.
E) nonparalytic polio

answer

C) bulbar poliomyelitis.

question

Enteroviruses are
A) more common in winter.
B) transmitted by fomites.
C) detected using serologic testing.
D) not common because numerous vaccines are available.
E) treated with antiviral agents

answer

C) detected using serologic testing.

question

Diseases caused by coxsackie A virus include
A) myocarditis.
B) hand-foot-and-mouth disease.
C) viral meningitis.
D) hepatitis.
E) hand-foot-and-mouth disease and viral meningitis

answer

E) hand-foot-and-mouth disease and viral meningitis

question

Which of the following viruses is suspected of being a cause of diabetes mellitusA) coxsackie A virus
B) coxsackie B virus
C) echoviruses
D) enteroviruses
E) hepatitis A

answer

B) coxsackie B virus

question

Which of the following viruses may cause viral meningitisA) echoviruses
B) rhinoviruses
C) coxsackie viruses
D) echoviruses and rhinoviruses
E) echoviruses and coxsackie viruses

answer

E) echoviruses and coxsackie viruses

question

Enteric hepatitis is fatal for 20% of people in which of the following groups?
A) infants under the age of one year
B) teenagers
C) young adults
D) pregnant women
E) elderly men

answer

D) pregnant women

question

How do coronaviruses differ from togaviruses?
A) They have an envelope.
B) They are RNA viruses.
C) They have helical capsids.
D) They contain positive RNA.
E) Their individual capsids can be visualized

answer

C) They have helical capsids.

question

Which of the following is a member of the Flaviviridae that is NOT an arbovirus?
A) Eastern equine encephalitis virus
B) Dengue virus
C) hepatitis C virus
D) hepatitis E virus
E) West Nile virus

answer

C) hepatitis C virus

question

The West Nile virus is considered a
A) rhinovirus.
B) coronavirus.
C) togavirus.
D) flavivirus.
E) enterovirus

answer

D) flavivirus.

question

The disease known as dengue hemorrhagic fever is actually
A) a hyperimmune response to reinfection with the dengue virus.
B) an immediate immune reaction to the initial infection with the dengue virus.
C) an antibody-antigen complex reaction.
D) an autoimmune disease.
E) the chronic carrier state of the dengue virus.

answer

A) a hyperimmune response to reinfection with the dengue virus.

question

Which of the following is MISMATCHEDA) Salk vaccine - requires boosters
B) Sabin vaccine - live attenuated vaccine
C) Salk vaccine - administered orally
D) Sabin vaccine - less stable
E) Salk vaccine - inactivated polio vaccine

answer

C) Salk vaccine - administered orally

question

Which of the following viruses is considered a childhood disease, was first identified by a German physician, and is known to cause "three-day measles"A) rubella
B) roseola
C) echovirus
D) coxsackie A virus
E) rhinovirus

answer

A) rubella

question

A child has a mild fever and a macular rash primarily on the torso. No lesions are evident in the mouth, and the child has not complained of pain. Which of the following diseases might the child haveA) hand-foot-and-mouth disease
B) three-day measles
C) red measles
D) dengue fever
E) Rocky Mountain spotted fever

answer

B) three-day measles

question

Diseases caused by echoviruses include
A) hepatitis.
B) common colds.
C) viral meningitis.
D) hepatitis and viral meningitis.
E) common colds and viral meningitis.

answer

E) common colds and viral meningitis.

question

Which of the following characteristics distinguishes coronaviruses from rhinovirusesA) They replicate best at 33°C.
B) They are transmitted via respiratory droplets.
C) They cause common colds.
D) An envelope is present.
E) The virions contain single-stranded positive RNA

answer

D) An envelope is present.

question

Which of the following enzymes allows retroviruses to transcribe dsDNA from ssRNAA) protease
B) trypsinase
C) integrase
D) reverse transcriptase
E) nuclease

answer

D) reverse transcriptase

question

The human T-lymphotropic virus 1 causes
A) hairy cell leukemia.
B) adult acute T-cell lymphocytic leukemia.
C) Hodgkin's lymphoma.
D) hepatic cancer.
E) Burkitt's lymphoma

answer

B) adult acute T-cell lymphocytic leukemia.

question

The SARS virus is a(n)
A) adenovirus.
B) rhinovirus.
C) coronavirus.
D) flavivirus.
E) togavirus.

answer

C) coronavirus.

question

A child has fever, chills, muscle aches, and conjunctivitis. She is also developing a rash caused by subcutaneous hemorrhaging and complains about exposure to sunlight. Which of the following viruses might she be infected withA) coltivirus
B) rotavirus
C) mumps virus
D) hantavirus
E) coxsackie B virus

answer

A) coltivirus

question

Which of the following cells is NOT infected by HIVA) helper T cells
B) microglia
C) B lymphocytes
D) macrophages
E) dendritic cells

answer

C) B lymphocytes

question

How are HIV virions rendered virulentA) The action of protease releases reverse transcriptase and capsomeres after the virion buds from the cell.
B) They bud to the surface of the host cell.
C) They use a chemokine receptor to remove gp120.
D) They bind to smooth muscle cells.
E) They contact the cytoplasmic membrane via gp41

answer

A) The action of protease releases reverse transcriptase and capsomeres after the virion buds from the cell.

question

A scientist discovers a new virus affecting birds. After isolation, the virus is characterized as having single-strand RNA in an icosahedral capsid and an envelope. To which of the following virus families might this new virus belongA) Coronaviridae
B) Flaviviridae
C) Orthomyxoviridae
D) Picornaviridae
E) Reoviridae

answer

B) Flaviviridae

question

Which of the following cells are a major reservoir for HIVA) helper T cells
B) B lymphocytes
C) cytotoxic T cells
D) infected dendritic cells
E) monocytes and macrophages

answer

E) monocytes and macrophages

question

Which of the following bodily fluids is commonly a source of infection by HIVA) breast milk
B) semen
C) vaginal secretions
D) semen and vaginal secretions
E) breast milk, semen, and vaginal secretions

answer

E) breast milk, semen, and vaginal secretions

question

An emerging fatal disease in humans caused by one of the members of the Paramyxoviridae is known as
A) Morbillivirus.
B) Nipahvirus.
C) respiratory syncytial virus.
D) Pneumovirus.
E) Rubulavirus.

answer

B) Nipahvirus.

question

Ebola hemorrhagic virus is caused by which type of virusA) filovirus
B) rhabdovirus
C) paramyxovirus
D) rubulavirus
E) pneumovirus

answer

A) filovirus

question

Public health scientists discover and become concerned about a new strain of RNA virus among farm animals, especially geese and pigs, in the Midwest. Each virion is composed of lipid, helical proteins, and multiple pieces of RNA. This new virus may be
A) a rotavirus.
B) an influenza virus.
C) a hantavirus.
D) a dengue virus.
E) a coronavirus.

answer

B) an influenza virus.

question

Which of the following pairs is MISMATCHEDA) mumps - parotitis
B) rabies - hydrophobia
C) measles - Koplik's spots
D) parainfluenza virus - croup
E) influenza - hemorrhagic fever

answer

E) influenza - hemorrhagic fever

question

A six-pointed star-shaped virus

answer

Astroviridae

question

Long, threadlike virions

answer

Filoviridae

question

Spherical with prominent glycoprotein spikes but no envelope

answer

Rotaviridae

question

Polyhedral capsids with glycoprotein spikes on an envelope

answer

Retroviridae

question

Negri bodies

answer

Rhabdoviridae

question

Herpangina

answer

Coxsackie A virus

question

Dengue fever

answer

Flaviviridae

question

Encephalitis

answer

West Nile virus

question

Hairy cell leukemia

answer

Human T-lymphotropic virus 2 (HTLV-2)

question

Pleurodynia

answer

Coxsackie B virus

question

Hepatitis A does not cause chronic liver disease, and complete recovery occurs 99% of the time. True/False

answer

T

question

In the United States, about 75% of children have antibodies to astroviruses. True/False

answer

T

question

Infection by all influenza strains can be prevented with vaccines. True/False

answer

F

question

Congenital rubella causes infants to be chronic asymptomatic carriers. True/False

answer

F

question

Coronaviruses cause gastrointestinal disease. True/False

answer

F

question

Rotavirus infection is easily treatable, but it is a leading cause of death among children around the world. True/False

answer

T

question

The practice of screening blood, blood products, and organ transplants for HIV has virtually eliminated the risk of HIV infection from these sources. True/False

answer

T

question

Infants infected with the coxsackie B virus do not develop myocarditis, and therefore the virus is rarely fatal. True/False

answer

F

question

A common complication of measles in adults, subacute sclerosing panencephalitis, could be a cause of diabetes mellitus. True/False

answer

F

question

Viremia is the release of virions into the urine. True/False

answer

F

question

________ is an RNA that can be used by a ribosome to translate protein.

answer

Positive RNA

question

The clinical term for "runny nose" is ________.

answer

rhinorrhea

question

Infection of day-care-age children with ________ results in mild respiratory disease lasting about two weeks, but infection in infants is potentially fatal.

answer

respiratory syncytial virus

question

Jonas Salk developed a(n) ________ vaccine in 1955.

answer

inactivated polio

question

Infection with ________ is the most common cause of diarrhea in children worldwide.

answer

rotavirus

question

Lesions of the mouth caused by coxsackie A virus are called ________.

answer

herpangina

question

Acute liver disease known as ________ is spread by the fecal-oral route and is caused by a picornavirus.

answer

infectious hepatitis

question

Arboviruses enter cells by way of ________ and replicate within them.

answer

endocytosis

question

RNA viruses that have more than one molecule of RNA are said to be ________.

answer

segmented

question

Rubella vaccine is made of ________ viruses and should not be given to pregnant women.

answer

live attenuated

question

Coronaviruses, like ________, replicate best at 33°C.

answer

rhinoviruses

question

________ have been studied more than any other group of viruses because of their unique features and the diseases they cause.

answer

Retroviruses

question

As HIV enters a T cell and macrophage, gp120-CD4 binds to a(n) ________ receptor, which removes gp120 from the virion.

answer

chemokine

question

________, an arenavirus that can cause hemorrhagic fever, can travel from human to human.

answer

Lassa fever virus

question

Viruses in the ________ family have similar morphologies and antigens and are able to cause infected cells to fuse with their neighbors, forming giant, multinucleate syncytia.

answer

Paramyxoviridae

question

Why do most individuals have more than one bout of the common cold in a season?

answer

The common cold can be caused by a number of different viruses, such as adenoviruses, coronaviruses, echoviruses, and paramyxoviruses. However, most colds are caused by the 100+ serotypes of rhinoviruses. Rhinoviruses are extremely infectious; a single virus is enough to cause a cold in 50% of infected individuals. Symptomatic or not, an infected person can spread viruses to the environment in large amounts. People of all ages acquire immunity to the serotypes they have been infected with in the past, but that immunity does not provide protection from infection with other serotypes. In addition, new serotypes are continuously being released into the population by mutations in the RNA of the virus, ensuring that no one can become immune to all rhinoviruses.

question

Compare and contrast the two polio vaccines used to nearly eradicate polio.

answer

Both vaccines are effective in providing immunity to all three strains of the polio virus, and both require booster vaccinations for complete immunity.
The first vaccine was developed by Jonas Salk in 1955 and is an inactivated polio vaccine (IPV). The Salk vaccine is inexpensive, is very stable in storage, and must be administered by injection. It poses no risk of causing disease.
Albert Sabin developed an alternative vaccine known as the oral polio vaccine (OPV), which is a live, attenuated vaccine. It is easier to administer (it is administered orally), but it is more expensive to prepare and is less stable in storage than the IPV. However, it can cause disease if administered to an immunocompromised person. The vaccine is a live, infectious agent, and people who have received the vaccine shed virus into the environment. There are two consequences of this property. On the one hand, the OPV can provide contact immunity, which is beneficial in areas where the polio incidence is high and vaccinating the entire population would be difficult for health care workers. On the other hand, the live vaccine can mutate to regain virulence and cause outbreaks of polio. One well-documented case of a polio outbreak caused by vaccine reversion occurred in 2001. For this reason, OPV use should be phased out as polio rates decline in a population.

question

Why was the discovery of reverse transcriptase a momentous event in biology?

answer

The discovery of retroviruses and their enzyme, reverse transcriptase, has made possible the ongoing revolution in genetic engineering and biotechnology. Scientists can more easily isolate mRNA for a specific protein and then use reverse transcriptase to make the DNA gene. Then, scientists can find the gene itself amid the full complement of DNA of an organism. The isolated gene and its product can be studied more intensively, and in some cases the gene product is available for use as a medication (e.g., human insulin), vaccine, etc.

question

Compare and contrast infectious hepatitis (hepatitis A) and hepatitis C in terms of agents, transmission, prevention, and disease outcomes.

answer

Both viruses are unsegmented positive-sense RNA viruses, and both target the liver.
Hepatitis A is a naked capsid virus transmitted by the fecal-oral route. It can persist on fomites and is resistant to some disinfectants. Nonetheless, good personal hygiene and food-handling practices can reduce transmission. A vaccine is available that prevents infection. Infectious hepatitis is an acute disease that rarely causes lasting liver damage.
Hepatitis C is an enveloped virus transmitted in bodily fluids. The presence of the envelope makes the virus much more fragile, and the virus does not persist on fomites. No vaccine is available to prevent transmission. Transmission is prevented by avoiding unprotected contact with infected bodily fluids and by screening blood products and organs. Hepatitis C infection produces chronic disease that may remain asymptomatic for decades. About 20% of infections may progress to symptomatic liver damage or failure, and a small percentage results in liver cancer.

question

Why are patients at risk vaccinated every year for influenza?

answer

Influenza is caused by two species of orthomyxoviruses. The genome of the virus is extremely variable, especially the genes that code for hemagglutinin and neuraminidase, which form the glycoprotein spikes for these viruses. This occurs through a process known as antigenic drift and antigenic shift. Antigenic drift refers to the accumulation of HA and NA mutations within a single strain of a virus in a given geographic location. This changes the antigenicity of the virus to the point that it becomes so antigenically distinct from previous strains that no one is immune to it. Antigenic drift leads to an increase in the number of influenza cases every two years or so. An antigenic shift is a major genetic change that results when genomes from different influenza virus strains reassort in a single host. This reassortment also changes the virus's antigenicity. Antigenic shift takes place every 10 years and is responsible for most pandemic strains. Therefore, because of the antigenic change of the causative agent, patients who are at risk should receive vaccination every year with vaccines developed against antigens of newly emerging influenza viruses.

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