viruses

Question 1

are viruses alive

Answer 1

debate over whether they’re alive or not because they don’t have an metabolism

Question 2

eradicated viruses

Answer 2

• smallpox →eradicated in 1979
• rinderpest → eradicated in 2011

Question 3

horizontal gene transfer (HGT)

Answer 3

gene transfer between unrelated donor + recipient

Question 4

transformation → HGT

Answer 4

naked DNA going into a cell

Question 5

conjugation → HGT

Answer 5

cells joined together

Question 6

transduction → HGT

Answer 6

viral particle transfers DNA

Question 7

inter-kingdom HGT

Answer 7

used for genetic modification of plants → exotic DNA inserted into the Ti plasmid

Question 8

transposable genetic elements

Answer 8

cell-free replication section of DNA

Question 9

transposon

Answer 9

mobile genetic elements → replicate after excision from genome

Question 10

retrotransposons

Answer 10

closely related to retroviruses → copied via RNA to DNA using reverse transcriptase enzyme

Question 11

capsid

Answer 11

protein coat for protection

Question 12

HIV lentivirus

Answer 12

single stranded, positive coding strand

Question 13

influenza orthomyxovirus

Answer 13

singe stranded, anti coding strand

Question 14

smallpox

Answer 14

• variola
• airborne dsDNA virus
• 30% mortality
• used as part of biological warfare
• first virus to be eradicated (1979)

Question 15

variolation

Answer 15

1715 → insertion of scab into cut on the back as from at-home vaccination; knowledge of resistance being formed due to previous infection

Question 16

yellow fever

Answer 16

• mosquito-borne
• spread by slave trade
• vaccine developed in 1937

Question 17

HIV

Answer 17

• identified in 1983
• effective therapy via antiretroviral drugs → reduce transmission + halt progression of AIDS
• no vaccine to this day

Question 18

class I virus

Answer 18

DNA virus → classical semiconservative

Question 19

class II virus

Answer 19

DNA virus → classical semiconservative, discard minus strand

Question 20

class III virus

Answer 20

RNA virus → classical semiconservative, but of RNA instead

Question 21

class IV vrius

Answer 21

RNA virus → makes ssRNA minus strand and transcribe from this to give ssRNA plus strand genome

Question 22

class V virus

Answer 22

RNA virus → make ssRNA plus strand and transcribe from this to give ssRNA minus strand genome

Question 23

class VI virus

Answer 23

RNA virus → make ssRNA strand genome by transcription off of minus strand of dsDNA

Question 24

class VII virus

Answer 24

DNA virus → transcription followed by reverse transcription

Question 25

structural proteins

Answer 25

make up the virus particle

Question 26

ns enzymes

Answer 26

(non structural proteins) needed for replication

Question 27

capsid

Answer 27

protein shell enclosing nucleic acid → made up of numerous capsomers

Question 28

nucleocapsid

Answer 28

capsid plus the enclosed nucleic acid

Question 29

virion

Answer 29

the complete infective virus particle

Question 30

outer shell purpose

Answer 30

protects nucleic acid from physical, chemical or enzymatic damage