Quiz 1 Flashcards
The correct order of the virus life cycle is:
a. Release, attachment, uncoating, penetration, biosynthesis, assembly
b. Release, attachment, uncoating, penetration, biosynthesis, assembly
c. Release, attachment, penetration, uncoating, biosynthesis, assembly
d. Attachment, penetration, uncoating, assembly, biosynthesis, release
e. Release, attachment, assembly, uncoating, biosynthesis, penetration
c. Release, attachment, penetration, uncoating, biosynthesis, assembly
Which statement is incorrect regarding the ‘Canyon hypothesis’?
A. The receptor-binding site is located at the bottom of a “canyon” on the viral capsomer.
B. An antibody molecule is too big to enter the canyon; therefore, the receptor binding site is “protected” from neutralizing antibody.
C. The cellular receptor is long and slim and therefore can access the viral receptor binding site.
D. Neutralizing antibody can bind the “rim” of the canyon and block receptor binding
E. Antigenic variation on the canyon rim alters receptor-binding specificity, which is determined by amino acids on the “canyon floor”.
E. Antigenic variation on the canyon rim alters receptor-binding specificity, which is determined by amino acids on the “canyon floor”.
Regarding attachment, which statement is incorrect?
A. Cell receptors may be protein, carbohydrate, or lipid
B. Attachment occurs via ionic interactions
C. Attachment is temperature-independent
D. Cells without the appropriate receptors are susceptible to infection
E. A virus particle attaches to a specific receptor (or co-receptors) on the cell surface
D. Cells without the appropriate receptors are susceptible to infection
Regarding membrane fusion, which statement is correct?
A. The viral envelope is derived from nucleocapsid.
B. Fusion is initiated by virus-encoded fusion proteins.
C. Fusion occurs at either the Golgi or endoplasmic reticulum.
D. Fusion between viral and cellular membranes allows entry into the nucleus.
E. Non-enveloped viruses can penetrate via membrane fusion.
B. Fusion is initiated by virus-encoded fusion proteins.
Regarding high patogenic avian influenza (HPAI), which statement is incorrect?
A. Compared with low pathogenic avian influenza, there are additional basic amino acids at the proteolytic cleavage site.
B. Furin-like proteases have a ubiquitous expression and explain the higher pathogenicity
C. Systemic infection occurs with HPAI.
D. HPAI exits the cell cleaved
E.Trypsin-like protease with limited distribution contributes to systemic infection.
E. Trypsin-like protease with limited distribution contributes to systemic infection.
This occurs in non pathogenic influenza viruses
Compared to DNA viruses, some unique features of RNA virus replication include the following EXCEPT:
A. Synthesis of viral mRNA and replication of viral genomes require viral encoded enzymes
B. RNA polymerases are more error prone, resulting in higher mutation rate than DNA viruses
C. Replication usually occurs in the cytoplasm
D. Genomes of retroviruses are transcribed into RNA by reverse transcriptase.
E. RNA viral genomes may be segmented or continuous; segmented genomes occur only in RNA viruses.
D. Genomes of retroviruses are transcribed into RNA by reverse transcriptase.
Retroviruses are transcribed into DNA by reverse transcriptase - they use RNA-dependent-DNA-synthesis
Compared to RNA viruses, some unique features of DNA virus replication include the following EXCEPT:
A. DNA viruses generally have larger genomes and a greater coding capacity.
B.Temporal patterns of gene regulation are characteristic of larger DNA viruses
C.Productive infections by DNA viruses are always cytocidal.
D.Most DNA viruses are potentially oncogenic.
E. Replication always occurs in the cytoplasm.
E. Replication always occurs in the cytoplasm.
Horses cannot contract Foot and Mouth Disease Virus. This is due to the fact the equine cells are not:
A. Susceptible
B. Permissive
C. Capable of productive infection
A. susceptible
Cytopathic effect (CPE) refers to virus-induced cellular changes visible by light microscopy. All of the following changes are characteristic of CPE EXCEPT:
A. Cell lysis
B. syncytial cell formation
C. inclusion bodies
D. surface glycoprotein arrangement
D. Surface glycoprotein arrangement
A proto-oncogene is:
A. A gene in a normal cell that gives rise to v-onc in a transforming virus
B. Cellular (c-onc) or viral (v-onc) gene whose products are able to transform cells
C. Gene whose product negatively regulates the cell cycle
D. A virally encoded protein that mediates fusion
A. A gene in a normal cell that gives rise to v-onc in a transforming virus
