Viruses_Bacteria_Achaea_A

Question 1

what type of parasites are viruses

Answer 1

obligate intracellular parasites

Question 2

where does virus replicate

Answer 2

inside other organism’s cells

Question 3

T/F every living studied organism has an associated virus

Answer 3

T

Question 4

do viruses outnumber all other life forms

Answer 4

yes, by at least 10X

Question 5

virology

Answer 5

study of viruses

Question 6

living characteristics of a virus

Answer 6

DNA/RNA

Question 7

non-living characteristics of a virus

Answer 7

need host cell to reproduce
no metabolism
un-responsive to stimuli

Question 8

Louis Pasteur

Answer 8

1884
looking for rabies cause
Found nothing under microscope
speculated infectious agent was too small for microscope

Question 9

Dimitri Ivanowsky

Answer 9

1892
passed crushed leaf extracts from tomato-mosaic virus infected plants through filter fine enough to filter bacteria. Filtered solution remained infectious

Question 10

Martinus Beijerinck

Answer 10

1898

repeated experiment of Ivanowsky. Suggested filtered solution contained new form of agent

Question 11

When did first images of viruses become visible

Answer 11

1937, electron microscope

Question 12

most important viral taxonomic criteria

Answer 12

Host organisms
Particle morphology: filamentous/isometric, enveloped/naked
genome type: RNA/DNA, circular/linear, ss/ds

Question 13

virus structure

Answer 13

nucleic acid core - made of RNA or DNA
protein capsid - consists of capsomeres
shape can be helical or icosahedral
envelope has tissue specific “spikes”

Question 14

viral genome, number of genes

Answer 14

3 - 100

Question 15

naked virus

Answer 15

virus without outer envelope

Question 16

how does a virus bind to host cell

Answer 16

capsid or envelope spikes bind to receptors on the host cell’s surface

Question 17

Lytic Cycle Steps

Answer 17

1) Bind: Virus capsid binds to cell receptors
2) Penetration: DNA/RNA penetrates cell
3) Biosynthesis: viral DNA/RNA cause viral components to be synthesized
4) Maturation: viruses assembled inside host cell
5) Release: cell bursts. Resultant viruses attack other host cells

Question 18

Prophage

Answer 18

Viral genetic code inside Bacteria DNA

Question 19

Lysogenic Steps

Answer 19

1) Attachment/Bind
2) Penetration
3) Integration: Viral DNA integrated into host cell’s chromosome (called a prophage)
4) Biosynthesis: Viral DNA leaves chromosome. (returns to Lytic)
5) Maturation
6) Release

Question 20

Virus Types in this class

Answer 20

Bacteriophage
DNA Viruses
RNA Viruses
Retroviruses

Question 21

Bacteriophage

Answer 21

viruses that attack bacteria

used in gene transfers

Question 22

Hersey-Chase 1952 experiment

Answer 22

used T4 bacteriophage to prove DNA, and not protein, is the genetic material.
Radioactively labeled Phosphorous (DNA) and Sulfur (protein). Phosphorous entered cell, Sulfur did not

Question 23

DNA Animal Viruses types

Answer 23

Herpesviruses
  Oral & Genital
  Chickenpox & Shingles
  Mononucleosis
Papillomaviruses
  Warts
  Associated with cervical cancers 95%

Question 24

RNA Animal Viruses

Answer 24

Picornavirus - small RNA virus
- Polio: neuromuscular disease
- Viral Hepatitis: liver infection
Rhinovirus
- common cold
- mutates rapidly
Orthomyxoviruses
- flu
Rhabdoviruses
- rabies
Hantavirus
- deadly pneumonia
Ebola virus
- hemorrhagic fever
Swine flu virus
- contaminated meat

Question 25

RNA Animal Retroviruses

Answer 25

``` Retrovirus: RNA Virus -> lysogenic DNA -> inserted into host genome uses reverse transcriptase enzyme HTLV - Human T-lymphotropic virus Cancer causing Virus HIV - Human Immunodeficiency virus AIDS ```

Question 26

How does HIV enter body

Answer 26

through blood or body fluid contact

Question 27

HIV Infection

Answer 27

- enters body through blood or body fluid contact - attaches to/penatrates Helper T-Lymphocytes - Reverse Transcriptase enzymes convert RNA viral code into DNA - DNA prophage spliced into host cell DNA - prophage may lie dormant or begin producing new viruses

Question 28

Viroids

Answer 28

naked strands of RNA (no capsid) | cause plant diseases

Question 29

Prions

Answer 29

proteinaceous infectious particles proteins that are folded abnormally cause enzyme changes in the brain agents of Mad Cow Disease and Scrapies

Question 30

other viral taxonomic criteria

Answer 30

disease symptoms antigenicity protein profile host range

Question 31

viral classification hierarchy

Answer 31

``` Order Family Subfamily Genus Species ```

Question 32

Baltimore virus classification

Answer 32

``` seven groups Nucleic Acid: DNA/RNA Strandedness: ss/ds Sense: sense(+)/antisense(-) replication method ```

Question 33

virus host range

Answer 33

range of cellular organisms a virus is capable of infecting

Question 34

HIV Viral Tissue Tropism

Answer 34

T cells

Question 35

Polio Viral Tissue Tropism

Answer 35

spinal nerve cells

Question 36

Hepatitis Tissue Tropism

Answer 36

liver cells