ch 2 subtopic virus

Question 1

molecular type of viroids

Answer 1

RNA of low molecular weight

Question 2

body organisation of viruses

Answer 2

non-cellular organisms

Question 3

characteristic of viruses

Answer 3

inert crystalline structure outside living cell

Question 4

how do they replicate?

Answer 4

once they infect a cell they take over the machinery of the host cell to replicate themselves, killing the host

Question 5

the term “virus” means

Answer 5

poison/venom

Question 6

who gave the term “virus”

Answer 6

dmitri ivanowsky

Question 7

which virus did dmitri ivanowsky find?

Answer 7

mosaic disease of tobacco

Question 8

how were virus found

Answer 8

they were found when they passed through bacteria filter paper and seen to be smaller than bacteria

Question 9

who showed viruses could be crystallised

Answer 9

WM Stanley

Question 10

what do viral crystals contain

Answer 10

large proteins

Question 11

behaviour of viruses

Answer 11

inert outside specific host cell

Question 12

nutrition of viruses

Answer 12

obligate parasites

Question 13

no virus contins both(RNA/DNA/RNA and DNA)

Answer 13

RNA and DNA

Question 14

a virus is chemically a

Answer 14

nucleoprotein

Question 15

the genetic material for virus is

Answer 15

infectious

Question 16

what is the genetic structure of plant attacking virus in general

Answer 16

single stranded RNA

Question 17

what is the genetic structure of animal attacking virus in general?

Answer 17

single/double stranded RNA or double stranded DNA

Question 18

what is the genetic structure of bacteriophages?

Answer 18

double stranded DNA

Question 19

protein coat of viruses is called

Answer 19

capsid

Question 20

subunits of the viral protein coat are called

Answer 20

capsomeres

Question 21

what does capsid protect

Answer 21

nucleic acid

Question 22

arrangement of capsomeres

Answer 22

helical or polyhedral

Question 23

diseases caused by virus in humans

Answer 23

1. AIDS
2. mumps
3. small pox
4. influenza
5. herpes

Question 24

symptoms of viral infection in plants

Answer 24

mosaic formation
leaf rolling
curling
yellowing
vein clearing
dwarfing
stunted growth

Question 25

who discovered viroids

Answer 25

T.O Diener

Question 26

which disease was the reason viroids were found

Answer 26

potato spindle tuber disease

Question 27

genetic structure of viroids

Answer 27

a free RNA of low molecular weight

Question 28

unlike viruses,viroids

Answer 28

are smaller and lack protein coat

Question 29

prions

Answer 29

infectious neurological disease causing agents made of abnormally folded protein

Question 30

size of prions

Answer 30

similar in size to viruses

Question 31

notable diseases caused by prions

Answer 31

bovine spongiform encephalopathy(BSE)[also called the mad cow disease in cattle]
cr-jacob disease(CJD) or the above equivalent, in humans

Question 32

lichens are

Answer 32

symbiotic associations between algae and fungi

Question 33

algal component of lichens

Answer 33

phycobiont

Question 34

fungal component of lichens

Answer 34

mycobiont

Question 35

nutrition of mycobiont

Answer 35

heterotrophic

Question 36

nutrition of phycobiont

Answer 36

autotrophic

Question 37

lichens are very good

Answer 37

pollution indicators