MICR 221 - Final Exam (Banfield)
Questions Complete With Verified
Answers
\Q\.T/F: viruses always kill the host - ANSWERS✔-false; require a place to live
\Q\.T/F: hosts fully kill all traces of virus - ANSWERS✔-false; by fully killing the virus, it enables
new pathogens to enter
\Q\.Example of Beneficial Host-Virus Relationships (2) - ANSWERS✔-1. Host - worm
Virus - polydnavirus from wasp eggs (prevents destruction of eggs in worm)
2. HERVs (retrovirus) causes residual glycoprotein in trophoblasts which fuse to form
syntitotrophoblast (leads to placental formation)
\Q\.HERVs - ANSWERS✔-human endogenous retroviruses that drive the evolution of the
placenta
\Q\.Which of the following statements are TRUE?
A. Least amount of biological diversity in viruses relative to other biological kingdoms
B. It is important to study virus/host interactions in order to defend against viruses
C. Viruses are extracellular parasites
D. Hosts fully kill all traces of viruses
E. Viruses kill of the host during infection - ANSWERS✔-B
,\Q\.CRISPER-Cas9 Genome Editing - ANSWERS✔--bacterium detects presence of virus DNA
-produces two short RNA (one contains sequence matching that of invading virus)
-two RNA form complex with CAS 9 nuclease
-complex invades nucleus and locks to PAN sequence
-guide RNA (one with matching sequence to target) finds viral DNA
-CAS 9 uses molecular scissors to cut out viral DNA enabling cell to repair cut (error prone)
leading to mutations to disable gene
-crisper system cut = DNA template can pair up with cut ends and replace with new error-free
version
\Q\.T/F: the CRISPER Cas-9 genome editing system degrades only the viral DNA gene -
ANSWERS✔-true via molecular scissors and replaces with new error free one (guide RNA
enables detection of viral DNA gene sequence)
\Q\.Why are we not always sick by viruses infection? (3) - ANSWERS✔-1. Host Defences
(immune system)
2. Microbial Specificity (very few viruses that can interact with specific human receptors)
3. Inapparent Functions (no symptoms)
\Q\.T/F: Viruses are the most abundant biological entity in the oceans and second largest
component of biomass after prokaryotes - ANSWERS✔-true
\Q\.Characteristics of a Virus - ANSWERS✔-- very small size (typically not viewed via light
microscope)
- produced from assembly of pre-formed components
- virus particles do not grow
- do not encode info for energy production, ribosomes, tRNAs, or lipid membrane synthesis
, \Q\.Which of the following is a characteristic of a virus?
A. growth
B. encoding info for energy production
C. contains rRNA and tRNA
D. large size
E. cannot synthesize lipid membranes - ANSWERS✔-E
\Q\._______ is a massive virus, assembled from pre-formed components that infects algae -
ANSWERS✔-Mimivirus
\Q\.5-Part Strategy for Virus Definition - ANSWERS✔-1. Build small particles containing nucleic
acid genome
2. Small genomes
3. Infectious cycle
4. Relationship with host (benign or lethal)
5. Overcome host defenses
\Q\.T/F: viruses cannot contain viruses within them - ANSWERS✔-false; i.e. Mimivirus containing
microvirus, Sputnik
\Q\.Plaque Assay - ANSWERS✔-Way of determine how much virus you have;
quantitation of virus
\Q\.________ is a technique used to quantify infectious virus production. - ANSWERS✔-Plaque
Assay
\Q\.General Method of Plaque Assay - ANSWERS✔--performing 10 fold dilutions of virus
Questions Complete With Verified
Answers
\Q\.T/F: viruses always kill the host - ANSWERS✔-false; require a place to live
\Q\.T/F: hosts fully kill all traces of virus - ANSWERS✔-false; by fully killing the virus, it enables
new pathogens to enter
\Q\.Example of Beneficial Host-Virus Relationships (2) - ANSWERS✔-1. Host - worm
Virus - polydnavirus from wasp eggs (prevents destruction of eggs in worm)
2. HERVs (retrovirus) causes residual glycoprotein in trophoblasts which fuse to form
syntitotrophoblast (leads to placental formation)
\Q\.HERVs - ANSWERS✔-human endogenous retroviruses that drive the evolution of the
placenta
\Q\.Which of the following statements are TRUE?
A. Least amount of biological diversity in viruses relative to other biological kingdoms
B. It is important to study virus/host interactions in order to defend against viruses
C. Viruses are extracellular parasites
D. Hosts fully kill all traces of viruses
E. Viruses kill of the host during infection - ANSWERS✔-B
,\Q\.CRISPER-Cas9 Genome Editing - ANSWERS✔--bacterium detects presence of virus DNA
-produces two short RNA (one contains sequence matching that of invading virus)
-two RNA form complex with CAS 9 nuclease
-complex invades nucleus and locks to PAN sequence
-guide RNA (one with matching sequence to target) finds viral DNA
-CAS 9 uses molecular scissors to cut out viral DNA enabling cell to repair cut (error prone)
leading to mutations to disable gene
-crisper system cut = DNA template can pair up with cut ends and replace with new error-free
version
\Q\.T/F: the CRISPER Cas-9 genome editing system degrades only the viral DNA gene -
ANSWERS✔-true via molecular scissors and replaces with new error free one (guide RNA
enables detection of viral DNA gene sequence)
\Q\.Why are we not always sick by viruses infection? (3) - ANSWERS✔-1. Host Defences
(immune system)
2. Microbial Specificity (very few viruses that can interact with specific human receptors)
3. Inapparent Functions (no symptoms)
\Q\.T/F: Viruses are the most abundant biological entity in the oceans and second largest
component of biomass after prokaryotes - ANSWERS✔-true
\Q\.Characteristics of a Virus - ANSWERS✔-- very small size (typically not viewed via light
microscope)
- produced from assembly of pre-formed components
- virus particles do not grow
- do not encode info for energy production, ribosomes, tRNAs, or lipid membrane synthesis
, \Q\.Which of the following is a characteristic of a virus?
A. growth
B. encoding info for energy production
C. contains rRNA and tRNA
D. large size
E. cannot synthesize lipid membranes - ANSWERS✔-E
\Q\._______ is a massive virus, assembled from pre-formed components that infects algae -
ANSWERS✔-Mimivirus
\Q\.5-Part Strategy for Virus Definition - ANSWERS✔-1. Build small particles containing nucleic
acid genome
2. Small genomes
3. Infectious cycle
4. Relationship with host (benign or lethal)
5. Overcome host defenses
\Q\.T/F: viruses cannot contain viruses within them - ANSWERS✔-false; i.e. Mimivirus containing
microvirus, Sputnik
\Q\.Plaque Assay - ANSWERS✔-Way of determine how much virus you have;
quantitation of virus
\Q\.________ is a technique used to quantify infectious virus production. - ANSWERS✔-Plaque
Assay
\Q\.General Method of Plaque Assay - ANSWERS✔--performing 10 fold dilutions of virus
