ch 16

Question 1

True or false: viruses are part of the 3 domains

Answer 1

False

Question 2

Are viruses living organisms and why?

Answer 2

they do not contain cells, metabolize or respond to stimuli

Question 3

Do viruses contain genetic material and reproduce?

Answer 3

Yes

Question 4

What are the 3 points of what viruses are?

Answer 4

1. genes wrapped in protein coat (capsid)
2. have either DNA or RNA
3. Some have an envelope which is an outer layer derived from the host cell’s plasms membrane

Question 5

Host Range

Answer 5

the kind of organisms or cells that a particular virus infects

Question 6

Reservoir

Answer 6

the site where a virus exists in nature

Question 7

Bacteriophage

Answer 7

a virus which infects bacteria

Question 8

Lytic infection

Answer 8

reproductive pathway in which a virus infects a bacterium, immediately replicates, then causes the host cell to burst in order to release the replicated viruses

Question 9

What are the 5 types of cells viruses can infect?

Answer 9

1. Tobacco mosaic virus (filamentous; single-stranded DNA)
2. T-even bacteriophage (spaceship; double-stranded DNA)
3. Rotavirus (spherical; double-stranded RNA)
4. Herpesvirus (icosahedral, enveloped; double-stranded DNA)
5. Poxvirus (oval, enveloped; double-stranded DNA)

Question 10

What type of organisms can viruses infect?

Answer 10

Plant, bacteria, and human host cells

Question 11

Lysogenic Infection

Answer 11

reproductive pathway in which the virus is replicated along with the bacterial host cell’s chromosome; the cell lives and reproduces for limited time before it bursts and releases the virus

Question 12

Prophage

Answer 12

the DNA of a lysogenic bacteriophage that is inserted into the host chromosome

Question 13

Latent Infection

Answer 13

virus remains dormant in host cell indefinitely

Question 14

Vaccine

Answer 14

“weakened” viruses which are used to help host build up immunity to more potent version of the virus

Question 15

5 steps of viral replication

Answer 15

1. virus attaches to host
2. virus penetrates cell and releases its DNA
3. host transcribes and translates viral DNA as if it were its own
4. New viruses assemble
5. Viruses leave the cell

Question 16

Are antibiotics effective for killing viruses?

Answer 16

No, since they are non-living

Question 17

Examples of viral infections

Answer 17

common cold, polio, warts, HIV, chicken pox, flu, herpes, and ebola

Question 18

2 non-cellular infectious agents other than viruses

Answer 18

Viroids and Prions

Question 19

Viroid

Answer 19

Smaller than a virus, naked strand of RNA, no protein coat

Question 20

Prion

Answer 20

Plasma membrane proteins which has an abnormal shape and can cause disease, Prions cause brain cells to die which many times leads to madness, insomnia, dementia, and eventually death.