infection and response

communicable

communicable

can be spread from person to person or animal to person

non-communicable

cannot be spread between people and animals

pathogen

microorganisms that can cause communicable diseases

fungi

reproduce by making spores which infect other plants and animals

fungal diseases

rose black spot

bacteria

reproduce rapidly inside the body

bacterial diseases

gonorrhoea, salmonella

virus

reproduce rapidly using the body’s cells and cell structures

viral diseases

measles, HIV & AIDS, TMV

protist

protists get transferred by vectors

vector

an organism that carries the disease but does not get the disease itself

body defence: eyes

produce tears which contain a natural antiseptic

body defence: hair and mucus in the nose

trap particles that could contain pathogens so it doesn’t enter further into the airway

body defence: stomach

produces hydrochloric acid which kills pathogens

body defence: blood

platelets seal open cuts and wounds

body defence: mucus and ciliated cells lining the trachea and bronchi

mucus traps pathogens which in turn are wafted back up the throat by ciliated cells where it can be swallowed

body defence: skin

forms a barrier to pathogens and secretes antimicrobial substances which kill pathogens

phagocyte

white blood cell which engulfs pathogens using the enzymes in it

antigen

substances on the surface of pathogens which the immune system detects as being foreign

antibody

small proteins made by white blood cells which bind to antigens as they’re complementary in shape and act as signals

lymphocytes

type of white blood cell which makes antibodies

vaccination

when a weakened/dead/inactive pathogen is injected into the body so it can create the appropriate antibodies in case of future infection

hybridoma

when a tumour cell and a lymphocyte are fused together

monoclonal antibody

when antibodies targeted for a specific disease are fused with a cell that divides rapidly in order to create many clones of the antibody

uses of monoclonal antibodies: cancer treatment

attach anti-cancer drug to antibody specific to cancer cells

uses of monoclonal antibodies: research

fluorescent dye attached to antibody specific to an antigen being studied enables scientists to locate the antigen

uses of monoclonal antibodies: pregnancy test

monoclonal antibodies specific to hCG have dye attached to them and become bound to other antibodies in the test zone if the hormone is present

signs of plant disease

discolouration, stunted growth, chlorosis

physical defense

structural defenses preventing pathogens from entering

chemical defenses

chemicals which are produced and released by the plant

mechanical defenses

adaptations of the plant to help defend itself