Viruses

Question 1

Why aren’t viruses considered living?

Answer 1

1. don’t respond to stimuli
2. do not consist of cells
3. no homeostasis
4. no metabolism

Question 2

Are viruses cellular or non cellular?

Answer 2

non cellular

Question 3

Name the 2 things that make up a virus

Answer 3

capsid, fiber proteins

Question 4

Is a virus or cell smaller?

Answer 4

a virus is smaller than a cell

Question 5

How do viruses reproduce

Answer 5

lytic cycle/lysogenic

Question 6

What protective covering is around the capsid of some viruses?

Answer 6

envelope

Question 7

Outside of host cells, viruses are ________

Answer 7

dormant

Question 8

Do viruses have ribosomes like cells?

Answer 8

no

Question 9

Do viruses have enzymes like cells?

Answer 9

yes

Question 10

Viruses use the ____, ____, and ____ of its host cells to be able to reproduce

Answer 10

mRNA, rRna, and tRna

Question 11

Name a type of cancer thought to be caused by viruses.

Answer 11

HPV

Question 12

What virus cause blisters that may appear around the mouth

Answer 12

herpes

Question 13

What virus is responsible for the common cold?

Answer 13

influenza, rhinoviruses

Question 14

What virus causes warts?

Answer 14

HPV

Question 15

what is a bacteriophage?

Answer 15

a virus that parasitizes a bacterium by infecting it and reproducing inside it

Question 16

What is the only part of the bacteria that actually enters the host cell of a bacterium?

Answer 16

Capsid

Question 17

What nucleic acid do retroviruses contain?

Answer 17

RNA

Question 18

What enzyme to retroviruses contain that let them make DNA from RNA?

Answer 18

RNA-dependent DNA polymerase

Question 19

What 2 things do retroviruses inject into their host cell when they attack them?

Answer 19

RNA and Reverse-transcriptase

Question 20

Give an example of a retrovirus

Answer 20

HIV

Question 21

What is a viroid?

Answer 21

small circular RNA molecules

without a protein coat

Question 22

Prions are infectious pieces of _________.

Answer 22

PrP (a protein)

Question 23

How do prions occur?

Answer 23

Most cases of prion disease arise spontaneously. More rarely prion disease is inherited due to a faulty gene, or acquired by medical procedures, transfusions, or contaminated food.

Question 24

What happens when prions get into the brain?

Answer 24

causes “holes” in the brain (cause neurons to rapidly degenerate)

Question 25

Viruses are host specific. What does this mean?

Answer 25

A host specific virus is one which can affect only one kind of host.

Question 26

Do the viruses that attack most animals also attack most humans?

Answer 26

no

Question 27

What is meant by cell lysis?

Answer 27

Cell lysis is a common outcome of viral infection. It consists of a disruption of cellular membranes, leading to cell death and the release of cytoplasmic compounds in the extracellular space.

Question 28

What are latent viruses?

Answer 28

dormant

Question 29

How long can latent viruses remain inactive?

Answer 29

years

Question 30

What activates latent viruses?

Answer 30

an external signal

Question 31

Example of latent virus?

Answer 31

Herpes Virus

Question 32

During the lysogenic cycle of a virus, what happens to the viral nucleic acid after it is injected into the host cell?

Answer 32

Viral acids form a circle in the center of the cell. The cell then mistakenly copies the viral acids instead of its own nucleic acids. Then the viral DNA organize themselves as viruses inside the cell. When the number of viruses inside becomes too much for the cell to hold, the membrane splits and the viruses are free to infect other cells.

Question 33

What is a prophage?

Answer 33

the genetic material of a bacteriophage

Question 34

What causes the phage or viral DNA to start replicating?

Answer 34

????

Question 35

Viral DNA along with the cell DNA is replicated during each ______ _______

Answer 35

binary fission

Question 36

One a prophage is active, the host cell is ____ making the virus deadly (or _____)

Answer 36

infected;virulent

Question 37

Genital herpes is called ________ ____ _

Answer 37

Herpes type 1

Question 38

Oral herpes is called _______ _____ _

Answer 38

Herpes Type 2

Question 39

How long does the herpes infection last?

Answer 39

lifetime

Question 40

Viruses make us sick because they _____ healthy hosts.

Answer 40

destroy

Question 41

Do antibiotics "kill" a virus?

Answer 41

no

Question 42

Besides our own immune systems, what can be done to prevent getting some viruses?

Answer 42

vaccines, safe sex, sanitation