pathogens and disease Flashcards
(11 cards)
Pathogens:
-micro-organisms which cause infectious diseases
inc. viruses, bacteria, protists or fungi
How can pathogens infect plants or animals?
-can infect plants or animals spread through direct contact, water or air
How are communicable diseases transmitted?
by air - pathogens can be carried in the air and then breathed in (a common example is a droplet infection, which is when sneezing, coughing or talking expels pathogens in droplets which can be breathed in)
direct contact - e.g. handshakes, kissing/sexual activity
indirect contact - touching contaminated surfaces
through contaminated water - e.g.
through drinking or coming into contact with dirty water
spread by use of a vector - e.g. mosquitoes
spread through contaminated food by eating it
-splashes of water can contain fungal spores which are responsible for spreading plant diseases.
How do pathogens make people feel ill?
-bacteria divide rapidly ( binary fission) produce toxins or damage cells making people feel ill
-reproduce very quickly inside body
- viruses take over cells in your body and live and reproduce inside them - damaging and destroying the cells.
Why are diseases much more spread than 100yrs ago?
-100yrs ago diseases like SARS and Ebola wouldn’t have left their country of origin
-due to ease of air travel
-people can fly around world and spread diseases to places they would’ve never otherwise reached
many Native Americans killed by diseases when the Colonial “Settlers” arrived, bringing strains of bacteria and virus their bodies had no immunity
How can the damage that communicable diseases cause to populations be reduced?
can be reduced by limiting the spread of pathogens
improve hygiene: hand washing, using disinfectants, isolating raw waste, using tissues and handkerchiefs when sneezing
isolating/reducing contact with infected individuals
removing vectors: using pesticides and removing their habitat
vaccination: by injecting a small amount of harmless pathogen into an individuals body, they can become immune to it so it won’t infect them - means they can’t pass it on
how do pathogens cause disease
- bacteria divide rapidly ( binary fission
what is the difference between bacteria and a virus
Bacteria:
-Living single-celled organisms
-Can reproduce on their own
-Can be helpful or harmful
-Treated with antibiotics
Viruses:
-Non-living particles (need a host to reproduce)
-Invade and hijack host cells to multiply
-Always harmful (cause diseases)
-Not affected by antibiotics; treated with antivirals or prevented by vaccines
How do viruses make individuals feel ill?
-viruses replicate themselves by invading cells
-viruses live and reproduce rapidly inside cells, causing cell damage
-the cell bursts and release new viruses into the bloodstream
-the damage and destruction of the cells makes you feel ill
How do bacteria make individuals feel ill?
-reproduce rapidly
-may produce toxins that damage tissues that makes you feel ill
How do bacteria cells multiply quickly?
-multiply very quickly by dividing process called binary fission
