Virus Flashcards
(18 cards)
What is the lytic cycle
A phage reproductive cycle that ends in the death of the host cell
What is a lysogenic cycle
Replication of the phage genome without destroying the host (infecting other host cells)
What are the steps of viral infection In bacteria
- Adsorption
- Penetration
- Uncoating/eclipse
- Transcription
- Synthesis of viral components
(structural and non structural) - Assembly
- Release
Adsorption
Host cell recognises virus (virus binds to receptor of host cell)
Virus (keys)
Host cell (key hole)
Penetration
Virus enters the host cell, happens by:
. Endocytosis
. Fusion
. Translocation
Transcription
Replication, copying the viral genome
Assembly
New viruses are encapsulated
Release
Lytic or lysogenic
Viruses can multiply by asexual and sexual reproduction
A) True
B) False
ANSWER: B
Genetic material of a virus can be
A) RNA
B) DNA
C) mRNA
D) None
ANSWER: A, B
Select the correct order of replication of viruses
A) Penetration, Adsorption, Uncoating, Synthesis of viral components, Transcription, Assembly, Release
B) Adsorption, Penetration, Uncoating, Transcription, Synthesis of viral components, Assembly, Release
C) Adsorption, Penetration, Uncoating, Transcription, Assembly, Synthesis of viral components, Release
ANSWER: B
Penetration occurs by the following
A) Translocation
B) Buffering
C) Sexual reproduction
D) Fusion
E) Exocytosis
F) Endocytosis
ANSWER: A, D, F
Viruses are predominantly made out of
A) Sterols
B) Carbohydrates
C) Proteins
D) Nucleic acids
E) Large cells with nucleus
ANSWER: C
An example of a virus exhibiting viral latency is
A) Sepsis
B) Herpes zoster
C) Orthomyxovirus
D) None of the above
ANSWER: B
An example of a virus exhibiting viral latency is
A) Sepsis
B) Herpes zoster
C) Orthomyxovirus
D) None of the above
ANSWER: B
Why are viruses not classed as living organisms
A) They cannot reproduce without the aid of a host
B) They do not metabolise food into energy
C) They do have organised cells
D) All of the above
E) None of the above
ANSWER: D
Some enveloped viruses use antigenic variation which makes it difficult for the immune system to recognise different strains of the virus. Which type of antigenic variation results in a major change in spike proteins due to gene reassortment?
Select one:
a. Antigenic drift
b. Antigenic shift
c. Antigenic draft
Antigenic shift
What kind of virulence factors are proteases, nucleases, phospholipases and glycohydrolases?
Question 33 Select one:
a. Adhesins
b. Capsules
c. Exoenzymes
d. Antiphagocytics
Exoenzymes
