pathogens are microorganisms that enter the body and causedisease
pathogens cause communicablediseases - diseases that are easilyspread
both plants and animals can be infected by pathogens
pathogens can be bacteria, viruses, protists or fungi
bacteria are verysmalllivingcells
bacteria are very small cells - about 1/100th the size of your body cells
bacteria cells can reproducerapidly inside your body
bacteria cells can make you feel ill by producing toxins that damage your cells and tissues
viruses are notcells
viruses are tiny - about 1/100th the size of bacteriacells
viruses reproducerapidly inside the body
viruses live inside your cells and replicate themselves using the cells machinery to produce many copies of themselves - the cell will then burst, releasing all the new viruses, this cell damage is what makes you feel ill
protists are single celled eukaryotes
some protists are parasites
parasitesliveon or inside other organisms and can cause them damage
parasites are often transferred to the organism by a vector, which doesn't get the disease itself
some fungi are single-celled
other fungi have a body which is made up of hyphae
hyphae is thread like structures
hyphae can grow and penetrate human skin and the surface of plants, causingdiseases
the hyphae can produce spores, which can be spread to other plants and animals
pathogens can be spread in different ways: water, air, directcontact
water: some pathogens can be picked up by drinking or bathing in dirtywater
air: pathogens can be carried in the air and can then be breathedin - some airbornepathogens are carried in the air in droplets produced when you sneeze or cough
directcontact: some pathogens can be picked up by touching contaminated surfaces - when touching the samesurface as an infected person