Micro Chapter 38 Flashcards
Which of the following viral diseases is spread via airborne transmission? A) West Nile Fever B) Smallpox C) Common cold D) Hepatitis A
B
The causative agent of both chicken pox and shingles is A) Variola virus B) Influenza C) Varicella-zoster virus D) Rhinovirus
C
Where does latent varicella-zoster virus reside until reactivated?
A) The cytoplasm of T cells
B) Nuclei of the cranial nerves and sensory nerves in the dorsal root ganglia
C) Interstitial spaces between skin cells
D) Retinal cells
B
The worst influenza pandemic on record occurred in A) 1918 B) 1957 C) 1968 D) 1977
A
Influenza virus enters host cells via A) Fusion with the cell membrane B) Injection of a polar tube C) Receptor-mediated endocytosis D) Phagocytosis
C
Influenza viruses are classified into subtypes based on which of the following characteristics A) Membrane surface glycoproteins B) Hemagglutinin (HA) spikes C) Neuraminidase (NA) spikes D) All of the above
D
What is the function of influenza hemagglutinin and neuraminidase spikes?
A) Assist in viral lysis
B) Aid in genome replication
C) Aid in viral attachment and virulence
D) Assist in capsid assembly
C
Which of the following events results in influenza epidemics and pandemics?
A) Antigenic drift or accumulation of minor mutations in HA and NA in a single strain of flu virus
B) Antigenic shift or the reassortment of genomes of two or more different strains of flu
C) Loss of HA and NA receptors
D) None of the above
B
Which of the following animals is involved in the transmission of influenza virus? A) Human B) Pig C) Birds D) All of the above
D
The most recent H1N1 influenza pandemic occurred in A) 1918 B) 1968 C) 1977 D) 2009
D
Which strain of flu led to the culling of millions of birds between 2003 and 2008 due to threat of bird-to-human transmission? A) H1N1 B) H2N1 C) H3N2 D) H5N1
D
The antiviral drugs zanamivir (Relenza) and oseltamivir (Tamiflu) combat the flu virus by which of the following mechanisms?
A) Degrading viral DNA
B) Blocking entry of the virus into the host cell
C) Blocking the release of virions from the host cell
D) All of the above
C
Where does the measles virus enter the host?
A) Through a puncture wound in skin
B) Through the intestinal mucosa
C) Through the respiratory tract or the conjunctiva of the eye
D) All of the above
C
The best way to prevent measles is through which of the following methods?
A) Social isolation
B) Water and sewage treatment
C) Use of condoms during sexual activity
D) MMR vaccination in childhood
D
Mumps is spread via A) Saliva and respiratory droplets B) Mosquito bites C) Direct contact D) Fomites
A
Which characteristic is the hallmark of the respiratory syncytial virus (RSV)?
A) Pores in the membranes or respiratory cells
B) Multinucleated masses of fused cells
C) Lysing of alveolar macrophages
D) All of the above
B
Which of the following diseases can lead to fetal death, premature delivery, or congenital heart defects? A) Measles B) Mumps C) Rubella D) Influenza
C
Which of the following groups of viruses is the causative agent of severe acute respiratory syndrome (SARS)? A) Coronaviruses B) Rhinoviruses C) Parainfluenza viruses D) Adenoviruses
A
Which of the following structures on coronaviruses aid in the attachment of virions to host cells? A) Sticky envelope B) Dense cilia C) Neuraminidase spikes D) Large peplomers
D
The initial outbreak of SARS originated in China in A) 1997 B) 2001 C) 2002 D) 2005
C
Global eradication of smallpox was possible because of which of the following features of the disease?
A) Only human hosts are reservoirs
B) There are virtually no asymptomatic carriers
C) The disease has a short period of infectivity
D) All of the above
D
Approximately what proportion of the world's population has not been vaccinated against smallpox and thus vulnerable to the disease? A) 10% B) 25% C) 50% D) 100%
C
The virus that causes which of the following diseases has the potential to be used as a bioweapon? A) Rubella B) Smallpox C) West Nile fever D) HIV
B
Which of the following diseases is caused by a viral pathogen spread via arthropod vector? A) Equine encephalitis B) Smallpox C) Poliomyelitis D) Human parvovirus B19
A
In the United States, cases of West Nile fever peak during which time of the year, corresponding with peak numbers of mosquitoes? A) Spring B) Early summer C) End of summer D) Fall
C
Which of the following is an example of a viral disease spread via direct contact between individuals? A) Measles B) AIDS C) Hepatitis A D) Ebolavirus
B
Which of the following viruses caused a global pandemic in the second half of the 20th Century? A) Hepatovirus B) Vaccinia C) HIV D) Human parvovirus B19
C
The gp120 envelope protein of the human immunodeficiency virus attaches to which of the following host cells? A) Skin cells B) Respiratory epithelial cells C) T-helper cells D) Liver cells
C
Transmission of HIV through which of the following routes makes it much more virulent? A) Breastfeeding B) Sexual activity involving semen C) Tainted blood transfusion D) Transmission from mother to fetus
B
How does HIV enter the host cell? A) Endocytosis B) Phagocytosis C) Injection of a polar tube D) Fusion with the cell membrane
A
What happens immediately after HIV enters the host cell?
A) RNA genome is copied into a single strand of DNA by the reverse transcriptase enzyme
B) RNA is degraded by ribonuclease H
C) The single strand of DNA is copied to form a double-stranded DNA genome
D) None of the above
A
Which of the following stages of HIV infection is characterized by a decline in helper T cells, increased serum antibody production, and generalized symptoms? A) Acute infection B) Asymptomatic stage C) Chronic symptomatic stage D) AIDS diagnosis
C
Which of the following stages of HIV infection is characterized by a T cell count of less than 200 cells in a microliter of blood and the appearance of opportunistic infections? A) Acute infection B) Asymptomatic stage C) Chronic symptomatic stage D) AIDS diagnosis
D
The most common method used for detection of anti-HIV antibodies in the blood is A) Real-time PCR B) Electron microscopy C) ELISA D) Plaque assay
C
Why is an effective vaccine for HIV unlikely?
A) The duration of the vaccine would be short-lived
B) HIV has a high mutation rate because reverse transcriptase lacks proofreading capabilities
C) Targeting infected T cells would damage the host immune system
D) None of the above
B
Transmission of herpes simplex virus type I (HSV-and herpes simplex virus type II (HSV-II) occurs via
A) Vectors
B) Inhalation of respiratory droplets
C) Direct contact of epithelial tissue surfaces
D) Contaminated water or food
C
During the active phase of herpes infection, blisters form as a result of A) Cell lysis B) Local inflammatory response C) Both A and B D) None of the above
C
During the latent phase of HIV infection, virions reside in A) Epithelial cells B) Nerve ganglia C) Intestinal mucosa D) Lymph nodes
B
The causative agent responsible for 50% of common cold infections are the A) Adenoviruses B) Coronaviruses C) Rhinoviruses D) Rotaviruses
C
What feature makes rhinoviruses resistant to the host immune system?
A) Large peplomers for attachment to host cells
B) Virions secrete virotoxins that destroy host cells
C) The capsid protein recognized by the immune system is hidden in a cleft
D) Once the virion enters the host, it induces a rapid lysis
C
Which of the following is the primary mode of transmission for the common cold?
A) Inhalation of respiratory droplets
B) Direct contact with infected individuals or fomites
C) Arthropod vectors
D) Ingestion of contaminated food or water
B
Which of the following diseases is asymptomatic in most individuals but becomes an opportunistic infection in patients with AIDS? A) Herpesvirus B) Human parvovirus B19 C) Hepatitis B virus D) Cytomegalovirus
D
What effect does cytomegalovirus have on host cells?
A) Causes lysis
B) Causes swelling
C) Causes formation of multinucleated masses
D) All of the above
B
Which of the following diseases is one of the most life-threatening infections in newborns in the United States? A) Cytomegalovirus B) Congenital herpes C) Rubella D) Hepatitis A
B
In the latent phase, the genital herpesvirus resides in which of the following locations? A) Helper T cells B) Respiratory epithelium C) Cells lining the genitourinary tract D) The sacral plexus of the spinal cord
D
95% of the individuals in the United States are exposed to this virus by age 3. A) HSV-1 B) HSV-2 C) HHV-6 D) Human parvovirus B19
C
Human parvovirus B19 is the causative agent of which of the following diseases? A) Congenital herpes B) Exanthem subitum C) Erthema infectiosum D) Chicken pox
C
The Epstein-Barr virus (EBV) is the causative agent of which of the following diseases? A) Cytomegalovirus B) Infectious mononucleosis C) Hepatitis D) None of the above
B
Which virus may be the most common virus in humans, infecting 80-90% of all adults worldwide? A) Epstein-Barr virus B) Herpesvirus C) Varicella-zoster virus D) Coronavirus
A
Which of the following are clinical signs of hepatitis B infection? A) Liver tissue degeneration B) Jaundice C) Hepatocellular carcinoma D) All of the above
D
The leading reason for liver transplantation in the United States is A) Hepatitis A B) Hepatitis B C) Hepatitis C D) Hepatitis G
C
What is the relationship between the hepatitis B virus (HBV) and hepatitis D virus (HDV)?
A) HBV is dependent upon HDV to provide the envelope protein for its RNA genome
B) HDV is dependent upon HBV to provide the envelope protein for its RNA genome
C) HBV and HDV are co-dependent on each other for a successful infection
D) There is no relationship between HBV and HDV
B
Currently, a vaccine is available for which of the following types of hepatitis virus? A) Hepatitis A B) Hepatitis B C) Hepatitis C D) Hepatitis D
B
The most common sexually transmitted viral disease in the United States today is A) HSV-2 B) Genital warts C) HIV D) None of the above
B
Which of the following viruses cause genital warts? A) Human papillomaviruses B) Herpesviruses C) Human parvoviruses D) Hepadnaviruses
A
Human papillomaviruses have been linked to which of the following cancers? A) Liver B) Lymphomas C) Leukemia D) Cervical
D
Which of the following viruses cause acute viral gastroenteritis? A) Rotaviruses B) Adenoviruses C) Caliciviruses D) All of the above
D
Which age group is most impacted by viral gastroenteritis? A) One year or under B) Elementary school children C) Teens and adults D) Senior citizens
A
Which of the following types of hepatitis is transmitted via fecal contamination of food or drink? A) Hepatitis A B) Hepatitis B C) Hepatitis C D) Hepatitis D
A
Paralytic polio results from
A) Multiplication of virions in the mucosa of the throat or small intestine
B) Invasion of the tonsils and lymph nodes of the neck and small intestine
C) Replication in the bloodstream
D) Invasion of the central nervous system
D
Which disease sparked the March of Dimes campaign in 1938? A) Hepatitis B) Congenital herpes C) Polio D) Rubella
C
Vascular leakage and dysfunction is a major symptom of which of the following diseases? A) Hepatitis B) Polio C) Measles D) Viral hemorrhagic fever (VHF)
D
The majority of the outbreaks of viral hemorrhagic fevers (VHFs) occur in this region. A) United States B) Africa C) South America D) Asia
B
Which of the following viruses is spread through rodent secretions and was first identified in the desert Southwest United States? A) Marburg virus B) Ebolavirus C) Hantavirus D) None of the above
C
Worldwide, almost all cases of human rabies are attributed to
A) Insect bites
B) Dog bites
C) Interaction with foxes, coyotes, and wolves
D) Contact with rodents
B
Rabies impacts which system of the body? A) Nervous B) Immune C) Circulatory D) Respiratory
A
Infectious protein particles are called A) Virusoids B) Viroids C) Prions D) Viroproteins
C
The primary symptom of transmissible spongiform encephalopathy (TSE) is A) Shaking B) Neuropathy C) Rash D) Dementia
D
Creutzfeldt-Jakob disease (CJD) in humans is spread via
A) Vector-borne transmission
B) Ingestion of beef contaminated with infected tissues
C) Direct contact with cattle
D) Inhalation of respiratory droplets
B
