Virus Lecture 17

Question 1

What was the phrase used to describe the first virus in regards to its ability to move through a mesh filter?

Answer 1

Contageum vivum fluidum

Question 2

The first virus found?

Answer 2

Tobacco mosaic virus

Question 3

What was the first animal virus filtered?

Answer 3

Foot and mouth disease

Question 4

T:F Viruses are the most abundant type of biological entity.

Answer 4

True

They are found in almost every ecosystem on earth

Question 5

What is a viruses size?

Answer 5

10^-7 m to 10^-8 m and need an electron microscope to see them.

Question 6

Are viruses intracellular parasites?

Answer 6

Yes. They are obligate intracellular parasites.

Question 7

T:F Viruses are sensitive to bacteria.

Answer 7

False

They are NOT sensitive to antibiotics

Question 8

Are viruses are sensitive to interferon?

Answer 8

Yes

Question 9

How do viruses gain energy?

Answer 9

They take over the host cellular metabolism.

Question 10

T:F Viruses do not have specific hosts?

Answer 10

False

Most viruses are host specific

Question 11

Virion

Answer 11

A complete virus particle that consists of an RNA or DNA core with a protein coat sometimes with external envelopes and that is the extracellular infective form of a virus.

Question 12

Any aspect of the infectious agent and includes: the infectious (Virion) or inactivated virus particle

Answer 12

Virus

Question 13

Why is the study of virology important?

Answer 13

Viruses cause high mortality and morbidity rates and some are zoonotic

Question 14

What is a capsid?

Answer 14

The protein shell of a virus. It usually is symmetrical and used in identification

Question 15

The basic subunit protein in the capsid of a virus is called?

Answer 15

Capsomer

Question 16

Nucleocapsid is?

Answer 16

Capsid + Virus Nucleic Acid (DNA or RNA)/Genome

Question 17

The lipid bilayer with embedded proteins that some viruses have is called?

Answer 17

Envelope

Question 18

What does the envelope do?

Answer 18

Facilitates entry into host and may help with immune system evasion.

Question 19

Virus Genome is either?

Answer 19

RNA or DNA

Question 20

Nucleic acid is either?

Answer 20

RNA
DNA
Both, but at different life stages

Question 21

Shape of nucleic acid

Answer 21

Linear
Circular
Segmented

Question 22

Strandedness

Answer 22

Single
Double
Double with regions of single

Question 23

Sense

Answer 23

Positive
Negative
Ambisense (+/-)

Question 24

Positive sense viral RNA is similar to?

Answer 24

mRNA and can be immediately translated by the host cell

Question 25

What sense viral RNA needs to be converted before translation?

Answer 25

Negative sense, it is complementary to mRNA

Question 26

What are the DNA Viruses

Answer 26

``` Circovirus Parvovirus Hepadnavirus Papovavirus Adenovirus Herpesvirus Poxvirus (I need one of Nic's inappropriate acronyms here) ```

Question 27

What steps must a virus go through to be successful?

Answer 27

Escape from the host or reservoir of infection Transport to the new host Entry to the new host Escape from the new host

Question 28

Vertical transmission

Answer 28

From mother to fetus or newborn at childbirth

Question 29

Transmission between members of the same species?

Answer 29

Horizontal transmission

Question 30

Cross species transmission

Answer 30

Transmission between species

Question 31

Transmission between humans to animals or vice versa?

Answer 31

Zoonosis (anthropozoonosis)

Question 32

Transmission of viral disease?

Answer 32

Person to person Food and water (fecal-oral) Insect vectors Fomites (nonliving objects)

Question 33

Steps virus replication

Answer 33

``` Attachment Penetration Uncoating Synthesis of viral nucleic acid and protein Assembly and maturation Release in large numbers ```

Question 34

What are the four outcomes for a cell after viral infection?

Answer 34

Cell Death- Lysis, Alteration Cell Membrane, Apoptosis (cell suicide) No apparent change to infected cell (Latent, Persistent or chronic infection) Fusion of cells- multinucleated (viral syncytium) Malignant Transformation (tumor)

Question 35

Characteristics of nercrosis

Answer 35

``` Chromatin clumping Swollen organelles Flocculent mitochondria Disintegration Release of intracellular contents Inflammation ```

Question 36

Characteristics of apoptosis

Answer 36

``` Mild convolution Chromatin compaction and segregation Condensation of cytoplasm Nuclear fragmentation Blebbing Apoptotic bodies Phagocytosis ```