Viruses

Question 1

how could one see a virus

Answer 1

using an electron microscope

Question 2

what specific type of nutrition do viruses have

Answer 2

they are obligate parasites

Question 3

what does it mean that they are obligate parasites

Answer 3

they can only replicate inside a living cell

Question 4

what type of cells do viruses infect

Answer 4

all types of cells

Question 5

what is peculiar about viruses

Answer 5

they are non cellular

Question 6

why can we say that viruses are non cellular

Answer 6

they don’t have a cell wall or cell membrane or any cell organelles

Question 7

what do viruses consist of?

Answer 7

a strand of DNA or RNA enclosed in a protein coat

Question 8

1 way of classifying viruses

Answer 8

based on their shape

Question 9

3 shapes of viruses

Answer 9

rod, spherical , complete

Question 10

what does the complex virus shape look like

Answer 10

like a spacecraft

Question 11

2 living features of viruses

Answer 11

they have genetic material (DNA or RNA)

they can replicate (within a living cell)

Question 12

4 non-living features of viruses // comment on the difficulty of classifying them as living things

Answer 12

they are non-cellular
they don’t have mitochondria, chloroplasts or ribosomes
they only have 1 type of nucleic acid (DNA or RNA)
they cannot replicate outside of a cell

Question 13

can viruses live outside of a living cell

Answer 13

yes, they just can’t replicate

Question 14

how long does the replication of viruses take?

Answer 14

about 30 minutes

Question 15

can viruses be grown on agar plates and explain

Answer 15

no as agar is not made of living cells, won’t be able to reproduce

Question 16

3 types of cells that viruses might have as a host

Answer 16

animal, plant and bacterium

Question 17

5 stages of viral replication

Answer 17

virus attaches to host cell
DNA replicates
assembly of viral DNA and protein
host cell bursts and it is released

Question 18

where does the virus attach to the host cell?

Answer 18

cell wall or membrane

Question 19

what goes inside/stays outside the host cell?

Answer 19

when the virus enters, the protein coat stays outside

Question 20

how does the virus replicate?

Answer 20

it uses the host’s organelles to produce copies of viral DNA and protein

Question 21

how are new viruses made?

Answer 21

by assembling the viral DNA and protein

Question 22

how many viruses can be released when the host cell bursts?

Answer 22

up to 100,000 new viruses

Question 23

3 things that happen to the new viruses after they are released

Answer 23

may infect other cells, be attacked by antibodies or white blood cells, or be released into the environment

Question 24

3 harmful effects of viruses

Answer 24

human disease
plant disease
anima disease

Question 25

3 human diseases caused by viruses

Answer 25

cold sores (herpes)
common cold
flu

Question 26

4 ways human disease can be contract from a virus

Answer 26

transfer of body fluids
by contacts
bt droplet infection
by a bite from a vector (carrier)

Question 27

what does plant disease result in?

Answer 27

crop damage

Question 28

1 plant disease caused by viruses

Answer 28

mosaic disease in tobacco plants

Question 29

2 animal diseases caused by viruses

Answer 29

foot an mouth eg. cow

rabies eg. dogs

Question 30

4 beneficial effects of viruses

Answer 30

genetic engineering (gene therapy)
kill bacteria (bacteriophages)
control pests (biological pest control)
formation of vaccines

Question 31

2 ways in which we can control vaccines

Answer 31

general and specific defence systems of the body control viral infection
vaccines are used to give protection against viruses

Question 32

are viruses affected by antibiotics

Answer 32

no