Virology Test #1 UPDATED ACTUAL
Questions and CORRECT Answers
Definition of a virus - CORRECT ANSWER - Agents that can pass through filters- filters
that trap most known bacteria
4 properties of viruses - CORRECT ANSWER - 1. Small size (can pass through filters that
otherwise trap bacteria)
2. Obligate, intracellular parasites
3. 2 basic components: nucleic acid genome and protein coat
4. Genome which may be RNA or DNA
Obligate, intracellular parasites? - CORRECT ANSWER - -Viruses must grow within
living cells
-Dependent on cells to supply energy and means of DNA and protein synthesis
-Dependent on cell mitochondria, ribosomes, and enzymes
2 basic components of a virus - CORRECT ANSWER - 1. nucleic acid genome
2. protein coat
True or false: all viruses have an envelope - CORRECT ANSWER - FALSE; some, but not
all
DNA virus shapes (3)
RNA virus shapes (3) - CORRECT ANSWER - DNA viruses can be single-stranded,
double-stranded, or circular
RNA viruses can be (+) or (-), segmented, or double stranded segmented
,*6 DNA VIRUSES* - CORRECT ANSWER - 1. PARVOVIRIDAE
2. PAPOVAVIRIDAE
3. HERPESVIRIDAE
4. POXVIRIDAE
5. HEPADNAVIRIDAE
6. ADENOVIRIDAE
True or false:
1. Viruses must use host cell processes to synthesize their own components
2. Viruses must ENCODE any required processes that are not provided by the cell - CORRECT
ANSWER - TRUE
True or false: Like eukaryotic cells (mitosis) and bacteria (binary fission), viruses replicate by
division - CORRECT ANSWER - FALSE:
Viruses are ASSEMBLED within the cell; they do NOT replicate by division
True or false: Viruses can be cultured on artificial media such as agar plates - CORRECT
ANSWER - FALSE:
Viruses require host cells to grow
1. What are the two types of viral capsid symmetry?
2. Describe each. - CORRECT ANSWER - -Icosahedral: geometric shape composed of 20
equilateral triangles; very stable structure
-Helical: nucleic acid in the middle is enclosed by proteins wrapped around it in a circular
fashion, creating a helical shape
*Two key properties of HELICAL shape viruses* - CORRECT ANSWER - All helical
viruses have...
1. An RNA genome
, 2. An envelope
Where are viral envelopes derived from? - CORRECT ANSWER - Viral envelopes are
derived from the cell membrane and are composed of membrane materials- lipid, protein,
glycoprotein
True or false: Viral envelopes are strongly resistant to things like acids, detergents, etc., and they
can survive well in the GI tract in the body
True or false: Viruses with viral envelopes are spread by close person-to-person contact (i.e.
blood, secretions, respiratory droplets) - CORRECT ANSWER - FALSE:
Viral envelopes are environmentally *LABILE*, meaning they are sensitive to acids, detergents,
and cannot survive in GI tract because of the strong acids present
TRUE
True or false: All icosahedral shaped viruses have an envelope - CORRECT ANSWER -
FALSE:
All HELICAL viruses have an envelope
CLICKER QUESTION FROM LECTURE:
All viruses...
a. have an envelope
b. have a DNA genome
c. depend on cell ribosomes to make viral proteins
d. have icosahedral capsid symmetry - CORRECT ANSWER - C: DEPEND ON CELL
RIBOSOMES TO MAKE VIRAL PROTEINS (obligate)
a. incorrect- some, but not all viruses have an envelope (all helical viruses do, however)
b. incorrect- viruses have either a DNA OR RNA genome
Questions and CORRECT Answers
Definition of a virus - CORRECT ANSWER - Agents that can pass through filters- filters
that trap most known bacteria
4 properties of viruses - CORRECT ANSWER - 1. Small size (can pass through filters that
otherwise trap bacteria)
2. Obligate, intracellular parasites
3. 2 basic components: nucleic acid genome and protein coat
4. Genome which may be RNA or DNA
Obligate, intracellular parasites? - CORRECT ANSWER - -Viruses must grow within
living cells
-Dependent on cells to supply energy and means of DNA and protein synthesis
-Dependent on cell mitochondria, ribosomes, and enzymes
2 basic components of a virus - CORRECT ANSWER - 1. nucleic acid genome
2. protein coat
True or false: all viruses have an envelope - CORRECT ANSWER - FALSE; some, but not
all
DNA virus shapes (3)
RNA virus shapes (3) - CORRECT ANSWER - DNA viruses can be single-stranded,
double-stranded, or circular
RNA viruses can be (+) or (-), segmented, or double stranded segmented
,*6 DNA VIRUSES* - CORRECT ANSWER - 1. PARVOVIRIDAE
2. PAPOVAVIRIDAE
3. HERPESVIRIDAE
4. POXVIRIDAE
5. HEPADNAVIRIDAE
6. ADENOVIRIDAE
True or false:
1. Viruses must use host cell processes to synthesize their own components
2. Viruses must ENCODE any required processes that are not provided by the cell - CORRECT
ANSWER - TRUE
True or false: Like eukaryotic cells (mitosis) and bacteria (binary fission), viruses replicate by
division - CORRECT ANSWER - FALSE:
Viruses are ASSEMBLED within the cell; they do NOT replicate by division
True or false: Viruses can be cultured on artificial media such as agar plates - CORRECT
ANSWER - FALSE:
Viruses require host cells to grow
1. What are the two types of viral capsid symmetry?
2. Describe each. - CORRECT ANSWER - -Icosahedral: geometric shape composed of 20
equilateral triangles; very stable structure
-Helical: nucleic acid in the middle is enclosed by proteins wrapped around it in a circular
fashion, creating a helical shape
*Two key properties of HELICAL shape viruses* - CORRECT ANSWER - All helical
viruses have...
1. An RNA genome
, 2. An envelope
Where are viral envelopes derived from? - CORRECT ANSWER - Viral envelopes are
derived from the cell membrane and are composed of membrane materials- lipid, protein,
glycoprotein
True or false: Viral envelopes are strongly resistant to things like acids, detergents, etc., and they
can survive well in the GI tract in the body
True or false: Viruses with viral envelopes are spread by close person-to-person contact (i.e.
blood, secretions, respiratory droplets) - CORRECT ANSWER - FALSE:
Viral envelopes are environmentally *LABILE*, meaning they are sensitive to acids, detergents,
and cannot survive in GI tract because of the strong acids present
TRUE
True or false: All icosahedral shaped viruses have an envelope - CORRECT ANSWER -
FALSE:
All HELICAL viruses have an envelope
CLICKER QUESTION FROM LECTURE:
All viruses...
a. have an envelope
b. have a DNA genome
c. depend on cell ribosomes to make viral proteins
d. have icosahedral capsid symmetry - CORRECT ANSWER - C: DEPEND ON CELL
RIBOSOMES TO MAKE VIRAL PROTEINS (obligate)
a. incorrect- some, but not all viruses have an envelope (all helical viruses do, however)
b. incorrect- viruses have either a DNA OR RNA genome
