Chapter 19

Question 1

viruses ____________ possess all properties of life

Answer 1

do not

Question 2

3 properties of life that viruses do not possess

Answer 2

• viruses are not cells
• viruses do not grow
• virsuses cannot reproduce on their own

Question 3

however viruses do ______________ some properties of life

Answer 3

possess

Question 4

4 properties of life that viruses possess

Answer 4

• viruses can replicate
• viruses possess genetic material
• viruses utilize the genetic code
• virsues evolve by natural selection

Question 5

_________________ produce genetic variability in viruses

Answer 5

mutations

Question 6

viruses can be as small as __________________

Answer 6

20 nm

Question 7

viruses consist of ____________ surrounded by __________________

Answer 7

genes (DNA and RNA)

protein coat

Question 8

a virus can consist of as few as _______________ genes

Answer 8

4

Question 9

_____________ is the protein coat of a virus

Answer 9

capsid

Question 10

some viruses are surrounded by a ____________________

Answer 10

membranous envelope

Question 11

_______________ which serve as receptor molecules are attached to the envelope

Answer 11

glycoproteins

Question 12

a virus enter the a host cell and is ___________________,

Answer 12

uncoated

Question 13

for a virus to be uncoated the DNA and ___________________ are seperated

Answer 13

protein capsid

Question 14

the host cell’s enzyme (DNA polymerase) _____________ the viral DNA

Answer 14

replicate

Question 15

the host cell’s enzyme (RNA polymerase) and ribosomes _________________ the viral DNA into RNA and proteins

Answer 15

transcription and translation

Question 16

_____________ undergo either a lytic cycle or a lysogenic cycle within their bacterial host cells

Answer 16

bacteriophages

Question 17

Bacteriaphages aka _______________ are viruses that infect bacteria

Answer 17

phages

Question 18

_______________ possess DNA as their genetic material

Answer 18

bacteriaphages

Question 19

a bacteriophages capsid consist of (3 things)

Answer 19

• head
• tail
• tailfibers

Question 20

a _________ that contains DNA is in a virus

Answer 20

head

Question 21

a ___________ that injects the DNA into the bacterium is in a virus

Answer 21

tail

Question 22

__________________ attach the bacteriophage to the bacterium

Answer 22

tailfibers

Question 23

during the ________________ the viral DNA incorporates itself into the bacterial chromosome

Answer 23

lysogenic cycle

Question 24

during the lytic cycle, the new viruses that are produced destroy the cell when they _______________________

Answer 24

break out of it

Question 25

lysogenic cycle does not harm the bacterial cell _____________, though viral DNA will ultimately exit the bacterial chromosome and initiate the ___________________

Answer 25

lytic cycle

Question 26

the viral DNA is replicated when the bacteria _______________ in the lysogenic cycle

Answer 26

divides

Question 27

lysogenic cycle does not harm the bacterial cell _____________, though viral DNA will ultimately exit the bacterial chromosome and initiate the ___________________

Answer 27

directly | lytic cycle

Question 28

viruses that infect plants possess ____________ as their genetic material

Answer 28

RNA

Question 29

viruses that infect animals may possess ___________ as their genetic material

Answer 29

DNA

Question 30

viruses infect plants by way of _________________ transmission

Answer 30

horizontal and vertical

Question 31

____________ transmission involves viral entry though damaged part of the plant - lesion due to wind or cold - insects feeding on the plant - gardeners using infecting tools

Answer 31

horizontal

Question 32

___________ transmission involves parents passing virus to their offspring

Answer 32

vertical

Question 33

animal viruses do not lyse their _______________

Answer 33

host cells

Question 34

DNA viruses causes:

Answer 34

- warts - cold sores and genetial herpies - chicken pox and shingles - mononucleosis - small pox

Question 35

in ______________________ affected individuals are susceptible to other infections that bodys immune system would normally be able to fight off

Answer 35

HIV

Question 36

RNA viruses cause:

Answer 36

- common cold - influenza - measels, mumps, rubella - hepatitudes - polio - rabies

Question 37

________________ are complex arrangements of molecules so they could represent an early transition between non life and life

Answer 37

viruses

Question 38

there is high turnover in ________________ cells so tissue damaged by a common cold can be replaces

Answer 38

respiratory system

Question 39

________________ cells do not divide and therefore cannot be replaced so polio is permanent

Answer 39

central nervous system

Question 40

the glycoproteins bind to recelptors on an animal host which mediated _____________________ of the virus into the cell

Answer 40

endocystosis

Question 41

new viruses exit the host cell by way of ______________ stealing some of the host membrane as their envelope

Answer 41

exocytosis

Question 42

viruses also frequently trigger the breakdown of ______________________ releasing damaging enzymes into the cell

Answer 42

lysosome

Question 43

there are vaccines that ____________ many viral infections

Answer 43

prevent

Question 44

medications can only ________________ viral infections once they are acquired

Answer 44

treat

Question 45

medications cannot ____________ viral infections

Answer 45

cure

Question 46

HIV _____________________ is the virus that causes AIDS ___________________________

Answer 46

human immunodificiency virus (HIV) | acquired immunodifficiency syndrom (AIDS)

Question 47

HIV infects ___________________________

Answer 47

leukocytes (white blood cells)

Question 48

HIV is a ______________ virus that function as a ___________________

Answer 48

RNA virus | retrovirus

Question 49

HIV uses an enzyme _______________ to produce | DNA from RNA template (many HIV drugs target this enzyme

Answer 49

reverse transcriptace

Question 50

however because viruses can only reproduce by living cells, _______________________________

Answer 50

cells must have existed prior to viruses

Question 51

Which came first Virus or cell?

Answer 51

the cell

Question 52

viroids are small ____________ molecules that infect _______________________

Answer 52

RNA | plants

Question 53

prions are small _________________ molecules that infect _________________________

Answer 53

proteins | animals

Question 54

_______________ the cause of mad cow disease in cows and creutzfielt-kakob disease in humans causes __________________

Answer 54

prions | causes brain damage