AQA Biology 1.1 pathogens

Question	Answer
what is a pathogen?	a micro-organism that causes disease
what are the 4 things a pathogen must do?	-gain entry to host -colonise tissue of host -resist host defences -damage host tissues
when does infection occur?	when the pathogen gets in and colonises the tissue
when does disease occur?	when an infection leads to recognisable symptoms
what is it called when a pathogen is transferred from one individual to another?	transmission
how do pathogens get into the body?	by penetrating one of the organisms interfaces with the environment
what are two common points of entry for a pathogen?	-the gas exchange system -the digestive system
what can be caused by pathogens entering the gas exchange system?	influenza, tuberculosis and bronchitis
what diseases can be caused by pathogens entering the digestive system?	cholera, typhoid and dysentery
what are three of the bodies natural defences?	-mucous layer forms thick, sticky layer that's difficult to penetrate on exchange surfaces -produce enzymes to break down pathogens -produce stomach acid which kills micro-organisms
what are the two main ways a pathogen affects the body?	-damages host tissues -produces toxins
what is an example of a pathogen damaging host tissue?	many pathogens break down the membrane of host cells
what determines how quickly a pathogen causes damage?	how rapidly the pathogen divides

Resource summary

	Created by Charlotte Hewson about 9 years ago