Chapter 13

Question 1

what are viruses

Answer 1

minuscule , acellular, infectious agents

Question 2

are viruses dna or rna

Answer 2

can be either

Question 3

what do viruses infect

Answer 3

animals, humans, plants, bacteria, and fungi

Question 4

are viruses sitll common in the industrialized world?

Answer 4

yes

Question 5

do viruses perform metabolism

Answer 5

no

Question 6

do viruses have independent replication

Answer 6

no

Question 7

are viruses alive

Answer 7

no

Question 8

what do viruses hijack

Answer 8

the hosts cells metabolic pathways

Question 9

what common cell features do viruses lack

Answer 9

cytoplasmic membrane, cytosol, and organelles

Question 10

what is extracellular mean

Answer 10

outside the host cell

Question 11

what does intracellular mean

Answer 11

inside the host cell

Question 12

viron def

Answer 12

a protein coat (capsid) surrounding nucleic acid

Question 13

what is a virus called when its outside the cell

Answer 13

a viron

Question 14

what do some virons have

Answer 14

some have phosholipid envelope

Question 15

what is the outermost layer of a viron for

Answer 15

for protection, and recognition sites

Question 16

what happens when the virus is inside the host cell

Answer 16

capsid is removed and the virus exists as nucleic acid

Question 17

genetic material of viruses is what . 3 points

Answer 17

may be DNA or RNA
can be single or double stranded
much smaller than the genome of cells

Question 18

what do most viruses infect

Answer 18

only particular host cells

Question 19

what are viral surface proteins attacted to

Answer 19

the host surface

Question 20

how can we classify viruses

Answer 20

by nuclei acid type, shape, size, or presence of envelope

Question 21

caspids def

Answer 21

protein coat

Question 22

what do caspids protect

Answer 22

protect viral nucleic acid

Question 23

what do caspids attach to

Answer 23

to host cells

Question 24

helical shape

Answer 24

oval ish rectangle

Question 25

polyhedral shape

Answer 25

sphere with pokes coming out of it

Question 26

spherical shape

Answer 26

a sphere

Question 27

complex shape

Answer 27

like a bacteriophage

Question 28

the viral envelope is a portion of what

Answer 28

evelope is a portion of host membrane

Question 29

where is the viral envelope acquired from

Answer 29

from host during viral release

Question 30

what is the viral envelope composed of

Answer 30

phospholipid bilayer and proteins

Question 31

bacteriophage is what

Answer 31

a virus that infects bacteria

Question 32

what are the 2 main cycles of bacteriophages

Answer 32

lytic and lysogenic

Question 33

lytic cycle isssss

Answer 33

when they quickly generate more virions and lyse the host cell (burst it )

Question 34

lysogenic cycle isssss

Answer 34

when the viral genome integrates into host genome and it replicates within host for many generations

Question 35

what are the 5 stages of the lytic cycle

Answer 35

attachment to host cell entry and cuts up host DNA synthesis and hijack trans. transl assembly of all the virion parts release out of the cell

Question 36

what does the lytic cycle hijack

Answer 36

they hijack host processes to produce new virions

Question 37

what phages perform lytic replication

Answer 37

virulent phages

Question 38

what phages perform lysogenic replication

Answer 38

temperate

Question 39

what does prophage mean

Answer 39

that phage DNA integrates into host genome

Question 40

what are the steps of the lysogenic cycle

Answer 40

phage attaches to the cell phage DNA enters the cell phage DNA integrates into the host DNA Last, the host cell replicates and passes down the phage genome to future generations

Question 41

whats beneficial of the lysogenic cycle

Answer 41

the virus can spread in the host population over time without killing the host cells

Question 42

could prophage enter the lytic cycle?

Answer 42

yes if specific stimuli trigger it to , like UV or chemicals

Question 43

what do the lytic and lysogenic cylce both do

Answer 43

accomplish the viruss goal of making copies of viral genome

Question 44

animal virus replication info about attachment

Answer 44

glycoprotein spikes or other molecules mediate attachment

Question 45

animal virus replication info about entry

Answer 45

it enters and uncoats

Question 46

DNA viruses in animal cells during synthesis

Answer 46

they oftern enter the nucleus where there are DNA polymerase and other tools to replicate DNA are

Question 47

RNA viruses in animal cells during synthesis

Answer 47

they often replicate in the cytoplasm where there are RNA polymerase, ribosomes, and other tools to replicate rna are

Question 48

special info about rna viruses replications

Answer 48

they need special enzymes

Question 49

retroviruses is what

Answer 49

a type of rna virus

Question 50

What do retroviruses do

Answer 50

use viral reverse transcription enzyem to synthesize DNA from rna

Question 50

what is the retrovirus different from

Answer 50

different from RNA dependent rna polymerase

Question 50

reverse transcriptase info

Answer 50

rna to dna

Question 50

what do retroviruses integrate

Answer 50

the reverse transcribed dna into the host genome

Question 50

latency def

Answer 50

when animal viruses remain dormant in host cells

Question 51

rna dependent rna polymerase info

Answer 51

rna to rna (copy of)

Question 52

what does latency incorporate

Answer 52

viral dna into host dna

Question 53

ex of latency

Answer 53

chicken pox coming back as shingles

Question 54

What do proto oncogenes promote

Answer 54

cell growth and division

Question 55

what can unctrolled activation of proto oncogenes lead to

Answer 55

cancer

Question 56

how much % might viruses cause of human cancers

Answer 56

20 to 25

Question 57

with no virus and a repressor what happens

Answer 57

no cancer

Question 58

with one virus and a repressor what happens

Answer 58

no cancer

Question 59

with a double hit of viruses and no repressor what happens

Answer 59

yes cancer