DNA Viruses (6) Flashcards Preview

MIIM30014 Virology > DNA Viruses (6) > Flashcards

Flashcards in DNA Viruses (6) Deck (28):
1

What do Rep78/68 do?
a. Allow for adenovirus to colonise the respiratory tract
b. Nick ds Parvovirus DNA to define the end of the genome
c. Bind to Parvovirus ITR to prime the ssDNA for replication
d. Prevent splicing of Poxvirus RNA




b. Nick ds Parvovirus DNA to define the end of the genome

2

What allows Poxvirus to replicate its genome in the cytoplasm?
a. The genome encodes extensive RNA splicing machinery that produces many different sized transcripts in the cytoplasm
b. It manipulates host RNA pol and DNA pol before entering the nucleus
c. Replication produces an immediate early T-protein which binds viral DNA and allows cytoplasmic replication
d. The virus encodes viral RNA pol, capping enzyme, polyA pol and DNA pol

d. The virus encodes viral RNA pol, capping enzyme, polyA pol and DNA pol

3

Which is a Baltimore class II virus? What does this mean?
a. Parvovirus. ssDNA is converted to +mRNA via a dsDNA intermediate
b. Adenovirus. Circular DNA can directly integrate into host DNA
c. Poxvirus. DNA is replicated in the cytoplasm
d. Herpesvirus. +ssRNA is duplicated to form dsDNA that can integrate into a host genome

a. Parvovirus. ssDNA is converted to +mRNA via a dsDNA intermediate

4

Which is correct?
a. Splicing occurs in Poxviridae and Hepadnaviridae
b. Only hepadnaviridae possess their own transciptase
c. Parvoviridae use cellular transcriptase and RNA is spliced
d. A viral reverse trancriptase is present in Papovaviridae

c. Parvoviridae use cellular transcriptase and RNA is spliced

5


What doesn’t constitute the Hepatitis B virus genome?
a. 3kb dsDNA
b. Viral polymerase
c. Four 12bp direct repeats
d. Capped RNA primer

c. Four 12bp direct repeats

6

• The Inverted Terminal Repeat on Parvovirus DNA is the primer and template for dsDNA synthesis.

T

7

• Poxvirus RNA can be spliced in the cytoplasm.

F

8

• Adenovirus, Parvovirus and Poxvirus all use DNA hairpin primers to replicate their DNA via strand displacement.

F

9

• As well as double walled virus particles, Hepatitis B virus has complete particles consisting of envelope proteins.

T

10

• There are four termination sequences in Hepatitis B mRNA.

F

11

What kind of viruses can directly fit into the flow of cell genetic information and can use cell enzymes?
a. dsDNA virsues and ss +RNA genome viruses
b. ss-RNA viruses
c. ss-RNA viruses and ss+ RNA viruses
d. ssDNA viruses and ds linear DNA viruses

a. dsDNA virsues and ss +RNA genome viruses

12

What is involved in cellular transcription?
a. RNA pol II binds downstream of the promoter
b. Transcription initiation factors bind the core promoter or enhancer sequences
c. RNA pol II is recruited directly by the enhancer
d. mRNA is synthesised from a DNA template using dNTPs

b. Transcription initiation factors bind the core promoter or enhancer sequences

13

What is false about transcriptional regulation in Papovavirus SV40?
a. VP2 and VP3 genes overlap and share some AAs due to being in the same reading frame
b. Early genes are transcribed in a counter clockwise direction and late genes are transcribed in a clockwise direction
c. Early promoters are recognised by host cell RNA transcription factors
d. The large T protein is produced following transcription of late genes

d. The large T protein is produced following transcription of late genes

14

Which DNA viruses carry their own polymerase?
a. Adenovirus and Papovavirus
b. Poxvirus and Herpesvirus
c. Adenovirus and Herpesvirus
d. Hepadnavirus and Poxvirus

d. Hepadnavirus and Poxvirus

15

What is not a function of the large T protein in Papovavirus SV40?
a. It initiates clockwise transcription and the activation of late viral genes
b. It suppresses DNA replication
c. It removes cellular proteins from DNA that repress transcription from the late promoter (antirepression)
d. It binds near the ori and unwinds Sv40 DNA

b. It suppresses DNA replication

16

What is false about DNA replication in Papovavirus SV40?
a. Large T protein hexamers bind near the ori and unwind DNA
b. Replication protein A binds after single strdned DNA binding proteins and leads to further unwinding of the DNA
c. RNA primers are extended by DNA Pol δ with replication factors RfC, Pcna
d. SV40 DNA replication is less efficient than cellular DNA replication, but there are fewer errors

d. SV40 DNA replication is less efficient than cellular DNA replication, but there are fewer errors

17

What is true about the mechanisms of viral dsDNA replication?
a. Papovaviruses and herpesviruses follow the fork method
b. The displacement mechanism always requires a RNA primer
c. There is no lagging strand when the Fork mechanism is used
d. Adenovirus replicates using a RNA primer and the Fork mechanism

a. Papovaviruses and herpesviruses follow the fork method

18

What are the roles of HSV-1 proteins VP16, ICP4 and ICP0?
a. VP16 stabilises the tegument layer
b. ICP4 and ICP0 initiate the transcription of early genes
c. ICP0 initiates immediate early gene transcription
d. VP16 activates late promoters to encourage DNA replication

b. ICP4 and ICP0 initiate the transcription of early genes

19

What is false about Adenovirus protein E1A?
a. It turns on the E2 early protein which relieves the promoter for structural gene transcription
b. It is extensively phosphorylated before entering the nucleus
c. It is a late protein and critical for the production of pTP
d. It is one of the first genes transcribed during Adenovirus infection

c. It is a late protein and critical for the production of pTP

20

• Viruses modulate abnormal cellular control mechanism to favour virus replication.

F

21

• The production of RNA requires a supply of dNTPS.

F

22

• All DNA viruses replicate in the nucleus except poxvirus.

T

23

• A Papovavirus SV40 viral particle has the DNA organised with histones in a minichromosome.

T

24

• When the transcription initiation complex is stabilised on DNA, the rate of transcription of viral proteins decreases.

F

25

• High levels of SV40 DNA dilute the concentration of cellular inhibitory binding proteins (IBP) from the late DNA promoter to allow activation of late genes.

T

26

• HSV-1 has a 126kb dsDNA genome with many ORFs, Terminal Repeats and Inverted Repeats.

T

27

• Circular DNA is primed by RNA which leaves a gap on the template following replication.

F

28

• In adenovirus, E1A an early protein and the enzymes it helps transcribe are late proteins.

F