MIC 319 Exam 2 2025 Questions and
Answers
Class 1 - ANS Knowing the enemy: Virology
What makes a virus unique? - ANS they are infectious, obligate intracellular parasites (cannot
replicate on their own, they need a host)
- the way it infects (receptor to infect)
- it needs conducive environment (to replicate)
- its genetic makeup
What percentage of human DNA comes from viruses? - ANS 8% of human DNA comes from
viruses
Why don't viruses we eat infect us? - ANS - they are dead (usually get cooked and die)
- we do not have a receptor for them (Tropism = every virus has a special molecule on their
surface for infection) plant viruses cannot infect animals and vice versa
- we have no survival habitat
What information do we get from physical measurement of virus particles? - ANS - the
number of virus particles
- the shape of the virus
- the size of the virus
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, - hemagglutination
- viral enzymes
- electron microscopy
- nucleic acids
- serology
does *NOT* give infectivity (alive or dead) of virus
What happens when we eat plant viruses? - ANS Nothing
How many classes of viruses are there? - ANS there are 7 classes of viruses based on their
nucleic acid and strandedness
- dsDNA
- gapped dsDNA
- SSDNA
- dsRNA
- SS (+) RNA
- SS (-) RNA
- SS (+) RNA with DNA intermediate
What are the biggest and smallest viruses? - ANS Smaller viruses can be around 20
micrometers
- example: poliovirus (30 nm)
Larger viruses can be around 1 um
- example: mimivirus and pandora virus
Pg. 2 Copyright © 2025 Jasonmcconell. ALL RIGHTS RESERVED.
Answers
Class 1 - ANS Knowing the enemy: Virology
What makes a virus unique? - ANS they are infectious, obligate intracellular parasites (cannot
replicate on their own, they need a host)
- the way it infects (receptor to infect)
- it needs conducive environment (to replicate)
- its genetic makeup
What percentage of human DNA comes from viruses? - ANS 8% of human DNA comes from
viruses
Why don't viruses we eat infect us? - ANS - they are dead (usually get cooked and die)
- we do not have a receptor for them (Tropism = every virus has a special molecule on their
surface for infection) plant viruses cannot infect animals and vice versa
- we have no survival habitat
What information do we get from physical measurement of virus particles? - ANS - the
number of virus particles
- the shape of the virus
- the size of the virus
Pg. 1 Copyright © 2025 Jasonmcconell. ALL RIGHTS RESERVED.
, - hemagglutination
- viral enzymes
- electron microscopy
- nucleic acids
- serology
does *NOT* give infectivity (alive or dead) of virus
What happens when we eat plant viruses? - ANS Nothing
How many classes of viruses are there? - ANS there are 7 classes of viruses based on their
nucleic acid and strandedness
- dsDNA
- gapped dsDNA
- SSDNA
- dsRNA
- SS (+) RNA
- SS (-) RNA
- SS (+) RNA with DNA intermediate
What are the biggest and smallest viruses? - ANS Smaller viruses can be around 20
micrometers
- example: poliovirus (30 nm)
Larger viruses can be around 1 um
- example: mimivirus and pandora virus
Pg. 2 Copyright © 2025 Jasonmcconell. ALL RIGHTS RESERVED.
