Mycology and Virology (Block 3) Flashcards
Who first discovered proof of viral infections in animals?
a) Louis Pasteur
b) Dimiti Ivanosky
c) Wendell Stanley
d) Loeffler and Frosch
D) Loeffler and Frosch
Who first discovered viruses?
a) Louis Pasteur
b) Dimitri Ivanosky
c) Wendell Stanley
d) Loeffler and Frosch
b) Dimitri Ivanosky disocered the first virus in tobacco plants
True or False
Viruses are opportunistic intracellular parasites
False
They are obligate intracellular parasites
Mimivirus and Medusavirus are considered what type of virus?
Giant Viruses
Most viruses have one capside except:
a) Retrovirus
b) Medusavirus
c) Reovirus
d) Influenza
c) Reoviruses have double layered capsids
What structure of the virus functions as protection, antigenic sites and attachments to host cells?
a) Envelope
b) Capsid
c) Capsomeres
d) Viral genome
b) Capsid
What virus structure facilitates entry into host cell and helps virus adapt to evade the immune system?
a) Capsomer
b) Nucleocapsid
c) RNA transport
d) Envelope
d) Envelope
What is the extracellular infective form of a virus?
a) Virion
b) Viremia
c) Viroid
d) All of the above
a) Virion
Small, circular RNA molecule that lacks a protein coat - only infects plants.
a) Virion
b) Viroid
c) Virium
d) Virus
b) Viroid
Which of the following is not a type of capsid symmetry?
a) Linear
b) Icosahedral
c) Helical
d) Complex
e) All of the above are true
a) Linear
In animal viruses, _______ nucleocapsids are always enclosed within a ________ envelope
Helical, Lipoprotein
True or False
In animal viruses, naked helical nucleocapsids are common
False
–> Common in plant viruses
What aggregate to form capsomers which are either hexons or pentons?
a) Capsomeres
b) Protomeres
c) Helical capsids
d) Capsids
b) Protomeres
Which of the following is NOT true of DNA viruses?
a) Very stable
b) Usually double stranded
c) Accurate replication w/ larger genomes
d) All of the above are true
d) All of the above are true
Which of the following is true of RNA viruses?
a) Less stable than DNA viruses
b) Typically a mixture of ds and ss
c) Error-prone replication
d) All of the above are true
d) All of the above are true
If there is no transcription needed and the strand is directly translated to proteins, what type of sense strand is this?
a) Negative sense
b) double stranded
c) Positive sense
d) anti-sense
c) Positive sense - genetic material has the same polarity as the viral mRNA so transcription is not needed
Which replication of single stranded RNA happens more quickly and why?
a) Positive Sense
b) Negative Sense
c) Both occur at the same speed
a) Positive is much faster because there is no transcription step
What is the purpose of the Baltimore Classification?
a) Clusters viruses into 7 groups
b) Based on replication strategy of RNA
c) Based on genome architecture
d) All of the above
d) All of the above
Influenza and Norovirus are both pathogens that can survive harsh environments. Because of this the main route of transmission is:
a) Direct
b) Airborne
c) Indirect contact
d) Doplets
c) Indirect
HIV, Ebola, and Herpesvirus survive best within the body and are transmitted via what route?
a) Direct
b) Airborne
c) Indirect contact
d) Doplets
a) Direct
Ebola can be transmitted via direct contact but also via _______ which do not survive long outside of the host.
a) Fecal Oral
b) Airborne
c) Indirect contact
d) Doplets
d) Droplets
The following can be transmitted via airborne transmission except:
a) Influenza
b) Tuberculosis
c) HIV
d) None of the above
C) HIV - requires direct contact
A cow is presenting with ocular and nasal discharge. Upon arrival, you notice that the cattle are closely housed with sheep and goats. What is a possible cause for the cow’s symptom if we are worried about cross-species contamination?
a) Ebola
b) Malingnant Catarrhal Fever
c) Bovine encephalitis
d) Bovine Respiratory Virus
b) Malignant Catarrhal fever
Which of the following statements if FALSE:
a) Viruses can survive off of their own energy
b) The viral genome contains only a few genes
c) Genes encode for structure components
d) All of the above are true
a) Viruses can NOT make their own energy or proteins
True or False
Membrane fusion is ONLY seen in enveloped viruses
True
True or False
Endocytosis is only for naked viruses
FALSE - Direct Penetration is only for naked viruses, endocytosis can occur in naked OR enveloped viruses
Which of the following statements about direct penetration is FALSE
a) Viral genome injection into host cell’s cytoplasm after attachment
b) Restricted to viruses that only need genome for infection ( + Sense)
c) It is pore-mediated
d) All of the above are true
d) All of the above are true
During what step do virions have loss of infectivity?
a) Replication
b) Uncoating
c) Maturation
d) Penetration
b) Uncoating
What enzyme is responsible for transcription (DNA to RNA)?
a) RNA polymerase
b) Reverse transcriptase
c) Ribosomal enzymes
d) RNA Dependent RNA polymerase
e) DNA polymerase
a) RNA polymerase
What enzyme is responsible for DNA replication?
a) RNA polymerase
b) Reverse transcriptase
c) Ribosomal enzymes
d) RNA Dependent RNA polymerase
e) DNA polymerase
e) DNA polymerase
What enzyme is responsible for RNA replication?
a) RNA polymerase
b) Reverse transcriptase
c) Ribosomal enzymes
d) RNA Dependent RNA polymerase
e) DNA polymerase
d) RNA dependent RNA polymerase
What enzyme is responsible for translation (RNA to protein)?
a) RNA polymerase
b) Reverse transcriptase
c) Ribosomal enzymes
d) RNA Dependent RNA polymerase
e) DNA polymerase
c) Ribosomal enzymes
Typically DNA viruses undergo mRNA synthesis and replication in the nucleus using host cell’s DNA-dependent RNA polymerase. What is the exception?
Pox Viruses - they are too large to synthesize in the nucleus
RNA viruses undergo mRNA synthesis and replication in the cytoplasm. What are the two exceptions?
Retroviruses and Influenza viruses
- They are RNA viruses but synthesize and replicate in the nucleus
True or False
Assembly and maturation ONLY occur in the nucleus
False
It occurs in the nucleus, cytoplasm and/or host cell membrane
The following are examples of mechanisms of release/shedding, EXCEPT:
a) Budding
b) Exocytosis
c) Cell lysis
d) Endocytosis
e) All of the above are examples
d) Endocytosis
True or false
Enveloped virions typically replicate/shed via budding
True
True or False
Naked virions replicate/shed via lysis of host cells
True
Most _________ require cell lysis to be released from the infected cell.
Bacteriophages
What type of life cycle is pictured
DNA virus
What type of life cycle is pictured
RNA viruses
What type of life cycle is pictured
Pox viruses
What type of life cycle is pictured
Bacteriophages
What type of life cycle is pictured
Influenza
What type of life cycle is pictured?
Retrovirus
During this phase of the viral growth curve, the infectivity of the virus disappears as the virus uncoats and replicates.
a) Eclipse
b) Latent period
c) Maturation
d) None - it never disappears
a) Eclipse
Replication of viral nucleic acid and protein occurs during what phase?
a) Eclipse
b) Latent period
c) Maturation
d) Assembly
b) Latent period
What term refers to the spread of viruses via the bloodstream?
a) Virulence
b) Viremia
c) Viroid
d) Virus
b) Viremia
Direct inoculation of virus into a host’s bloodstream and no replication at the site of entry, for example via contaminated syringes or insect bites, refer to what type of viremia?
a) Active
b) Primary
c) Secondary
d) Passive
d) Passive
