a pathogen is a microorganism that causes disease. they live in hosts. hosts creat a good habitat for them to live in
1 of 18
what are the different types of pathogens?
bacteria , fungi, virus and protoctista
2 of 18
how does bacteria cause disease?
bacteria are small prokarytoes that reproduce rapidly in the right conditions in a host. thier presence can damage cells and release toxins that are toxic to the host
3 of 18
how does fungi cause disease?
fungus can live in the skin of animals where its hyphae which form a mycelium form under the skin. fungus can send out specialised reproductive hyphae which grow to surface of the skin to release spores which causes redness and irritation
4 of 18
how does fungi cause disease in plants?
fungus(often in the vascular tissue) can release extracellular enzymes eg cellulase to digest the surrounding tissue which causes decay and leaves will discolour and shrivel up
5 of 18
how does virus cause disease?
virus invade cells and take over genetic machinery and organelles. they then cause the cell to manufacture more copies of the virus. host bursts leaving new virus to infect healthy cells.
6 of 18
how do protoctista cause disease?
enter host cells and feed on the contents as they grow eg malarial parasite plasmodium feeds on haemoglobin inside red blood cells
7 of 18
what is direct transmission?
passing a pathogen from host to new host with no intermediary. eg touching contaminated surfaces
8 of 18
what is indirect transmissions?
passing a pathogen from host to new host via a vector eg mosquito being the vectors for maleria
9 of 18
what is a transmission?
passing a pathogen from an infected individual to an uninfected individual
10 of 18
what is a vector?
an organism that carries a pathogen from one host to another
11 of 18
what is a droplet infection? how do you stop transmissions?
an infection in which the pathogen is carried in tiny water droplets in air. you can eg cover your mouth when sneezing to stop transmissions of influenza
12 of 18
what is feacal oral transmissions? how do you stop transmissions?
they are transmission of eating or drinking water that is contaminated by a pathogen. you can stop transmissions by teatment of waste water and drinking water . washing all fresh food and cooking thoroughly
13 of 18
what is spores transmitions? how do you stop transmissions?
spores are a resistant stage of a pathogen. cal be carried in air/surfaces/soil. you can use a mask and you can wash yoir skin after touching soil
14 of 18
what are other factors that affect transmissions including social factors?
overcrowding, poor ventillation, poor health, homelessness, poor diet, working with people who migrated from diseased countries
15 of 18
how are transmissions made in plant pathogens?
pathogens present in soil enter roots/ fungi produce spores which are carried in the wind/ pathogens can affect vascular tissue. leaves that shed will take pathogens back into tho soil and infect other plants/ pathogens in friut and seed
16 of 18
how are indirect transmissions made in plants?
vectors such as beetles. they will attack an infected plant. and then they will go and attack an uninfected plant transmitting the pathogen
17 of 18
how does climate affect transmissions?
bacteria and fungi can grow and reproduce more rapidly in warm and moist conditions so disease tends to be common in warmer climates.
Comments
No comments have yet been made