Tuberculosis (TB) Bacteria
Animals
Bacterial meningitis Bacteria
Humans
Ring rot Bacteria
Potatoes, tomatoes
HIV/AIDS Virus
Humans
Influenza Virus
Animals
Tobacco mosaic virus (TMV) Virus
Plants
Malaria Protoctista
Animals
Potato/tomato late blight Protoctista
Potatoes, tomatoes
Black sigatoka Fungi
Bananas
Ringworm Fungi
Cattle
Athlete’s foot Fungi
Humans
3 causes of direct transmission Direct contact, inoculation, ingestion
Vectors Transmits communicable pathogens from
one host to another via indirect
transmission
3 causes of indirect transmission Fomites, droplet infection and vectors
, 3 factors affecting transmission of disease Living conditions, social factors and climate
How do living conditions affect the Overcrowded living conditions increases the
transmission of disease transmission of many communicable
diseases
How do social factors affect the Good healthcare ensures the most effective
transmission of disease anti-HIV drugs are likely available
Good education informs people about the
transmission of HIV and how it can be
avoided
Physical plant defences against pathogens - Waxy cuticles on the leaves and
stems provide physical barriers
against pathogen entry and stop
water collecting on the leaf, reducing
the risk of pathogens transmitted via
vectors
- Cell walls act as physical barriers
against pathogens; callose is
deposited between cell walls and
plasma membranes during times of
stress e.g. pathogen invasion
- Callose deposition at the
plasmodesmata limits the spread of
pathogens between cells
Chemical plant defences against pathogens - Plants produce antimicrobial
chemicals which kill/inhibit
pathogens
- Insecticides, chemicals which are
toxic to insects, are secreted by
plants reducing the risk of infection
on plants transmitted by insect
vectors
List the primary non-specific animal Skin, mucous membranes, blood clotting,
defences against pathogens inflammation, wound repair, expulsive
reflexes
How does the skin defend against - Prevents pathogens from entering
pathogens the body
- Produces antimicrobial chemical
which lower pH, thus inhibiting the
growth of pathogens
How do mucous membranes defend Mucus is secreted which is a sticky
against pathogens substance that traps pathogens and
contains antimicrobial enzymes
How does blood clotting defend against Plugs wounds to prevent pathogen entry
pathogens and blood loss when platelets are exposed
to damaged blood vessels by forming a
mesh of protein (fibrin) fibres