Immunity and communicable diseases

Question 1

define what a pathogen is

Answer 1

a microorganism which can cause a disease

Question 2

what are the 4 categories of pathogens

Answer 2

bacteria
fungi
protoctisca
viruses

Question 3

give 3 characteristics of bacteria

Answer 3

genetic material is not found in a membrane bound nucleus it is found in cytoplasm

no membrane bound organelles

The cell wall is made up of peptidoglycan

Question 4

what are toxins

Answer 4

chemicals which damage the host cells and tissues

Question 5

give 3 characteristics of viruses

Answer 5

non-living

cannot reproduce outside of a host cell

genetic material is wrapped in a protein structure called capsid

Question 6

define an antibiotic

Answer 6

a compound that kills or inhibits the growth of bacteria

Question 7

how do viruses cause a viral infection

Answer 7

viruses invade the living cell
genetic material of the virus takes over the biochemistry of the host cell to make more viruses
reproduce very fast
evolve by by developing adaptations to their host cell

Question 8

what type of organism are fungi

Answer 8

eukrayotic

Question 9

how do fungi obtain nutrients

Answer 9

they digest their food extracellularily
release enzymes and digest the material around them
this causes damage to the host cell’s tissues

Question 10

what is released when fungi reproduce

Answer 10

spores

Question 11

what causes fungi diseases to spread quickly

Answer 11

spores

Question 12

how does fungi affect plants

Answer 12

they attack the leaves
this reduces the rate of photosynthesis
this kills the plant
this reduces the crop yield

Question 13

give 3 characteristics of protists

Answer 13

they use hosts
they may need a vector to transport it to the host
they can enter the body through polluted water

Question 14

how do protists attack and damage the host’s tissues

Answer 14

they take over cells
break them open once the new generation starts to merge
they don’t take over the genetic material of a cell
they digest and use the the cell components as they reproduce

Question 15

how do fungi attack and damage the host’s tissues

Answer 15

digest living cells and destroy them

Question 16

how do toxins cause damage to the host

Answer 16

they poison or damage the host such as breaking down the cell membrane, some damage or inactivating enzymes and some interfere with the cell hosts’ genetic material,

Question 17

what pathogen causes ring rot

Answer 17

bacteria

Question 18

what does ring rot damage

Answer 18

leaves, tubers, fruit

Question 19

what pathogen is tobacco mosaic virus

Answer 19

virus

Question 20

what does TMV damage

Answer 20

leaves
flowers
fruits

Question 21

what pathogen causes TB

Answer 21

bacteria

Question 22

what damage does TB do

Answer 22

it damages and destroys lung tissue and supresses the immune system

Question 23

is there a cure for TB, if so what is it?

Answer 23

antibiotics

Question 24

how is TB prevented

Answer 24

improving living standards and vaccinations

Question 25

what damage does bacterial meningitis do

Answer 25

a bacterial infection on the protective surfaces on the brain which can spread to the rest of the body and causes blood poising and rapid death

Question 26

if there is a cure for bacterial meningitis what is it

Answer 26

antibiotics

Question 27

what prevents bacterial meningitis

Answer 27

vaccines

Question 28

what is influenza

Answer 28

viral infection of the ciliated epithelium, it kills them, leaving airways open to secondary infection

Question 29

how is malaria transported into the human

Answer 29

the parasite reproduces inside the female mosquito

the female needs to take two blood meals for the protein to lay eggs

the parasite invades the human

it invades the red blood cells, liver and brain

Question 30

give 5 factors affecting the transmission of communicable diseases in animals

Answer 30

over-crowding
poor nutrition
a compromised immune system
culture
climate change

Question 31

give 3 ways that pathogens can be transmitted in plants

Answer 31

vectors
wind
water

Question 32

give 5 factors affecting the transmission of communicable diseases in animals

Answer 32

planting varieties of crops that are susceptible to diseases
overcrowding
poor mineral nutrition reduces resistance of plants
damp, warm conditions increase the survival and spread of pathogens
climate change

Question 33

are plants passive or active

Answer 33

active

Question 34

what is meant by active and passive immunity

Answer 34

active immunity is made by the organism themselves

passive immunity is through the use of medication and antibiotics

Question 35

describe how plants recognise an attack

Answer 35

receptors in the cells respond to the molecules from the pathogens or to the chemicals that damage the plant cell wall

stimulates the release of signalling molecules that appear to switch on genes in the nucleus

this triggers cellular responses

Question 36

give 3 examples of cellular responses from plants

Answer 36

defensive chemicals
sending alarm signals to unaffected cells
physically strengthening the cell walls

Question 37

give an example of a physical defence by plants

Answer 37

they produce high levels of the polysaccharide called callose (can act as barriers and block sieve pores in phloem)

Question 38

give 3 examples of chemical defences by plants

Answer 38

insect repellents (e.g. pine resin)

antibacterial compounds

general toxins