types of pathogen Flashcards
what are the 4 main types of pathogen
bacteria
virus
fungi
protoctist
outline the basic structure of bacteria
- prokaryotic cells
- no membrane bound organelles
- DNA in a plasmid ring floating freely in the cytoplasm
what are the 2 types of bacteria
GRAM positive or negative
how do bacteria reproduce
binary fission - cell doubles in size and splits in 2
give 3 examples of diseases caused by bacteria
tuberculosis
bacterial meningitis
ring rot
tuberculosis
- organisms affected
- how does is spread
- affects mammals
- spreads via airborne germs
bacterial meningitis
- organisms affected
- how does is spread
- affects humans, mostly babies
- spreads via saliva
ring rot
- organisms affected
- how does is spread
- affects potato plants
- spreads through soil + water
outline the basic structure of viruses
- non living infectious agent
- RNA surrounded by protein
how do viruses reproduce
by the lytic and lysogenic cycles
what is the lysogenic cycle
- virus attaches to cell
- injects RNA which becomes incorporated into hosts DNA
- virus genetic information is spread when cell DNA is replicated
- proteins made - these form viruses
- this can go on indefinitely
what is the lytic cycle
- virus attaches to cell
- injects RNA which becomes incorporated into hosts DNA
- virus genetic information is spread when cell DNA is replicated
- proteins made - these form viruses
- these break/lyse the cell and spread
how do viruses burst out of host cells
they perforate the membrane, causing water to flow in so the cell bursts
why can some viruses remain undetected for a long time
this is because they can remain in the lysogenic cycle indefinitely before switching to the lytic cycle + burst out
why is virus genetic material hard for host cells to detect
they use reverse transcription to turn RNA into DNA so its less noticeable
what type of organism is always pathogenic + why
viruses - they can only reproduce with a host cell, parasitic
- they can also cause disease in any organism
give 3 examples of diseases caused by viruses
- AIDS through HIV
- influenza
- tobacco mosaic virus
AIDS
- organisms affected
- how does it spread
- affects humans
- progression of HIV which spreads through exchange in sex / bodily fluids
influenza
- organisms affected
- how does it spread
- affects humans + some animals
- spreads via airborne germs
tobacco mosaic virus
- organisms affected
- how does it spread
- affects tobacco plants
- spreads on workers hands / tools
2 things that make fungi different from other types of pathogen
- often they are multicellular
- they tend to grow on organisms rather than invading bodies/cells - so less harmful
how do fungi gain nutrients
they are saprophytic - feed on decaying matter
they can also be parasitic
what type of fungi are pathogenic + why
parasitic fungi are pathogenic - they feed on living organisms
how do fungi reproduce
by releasing spores which can spread huge distances
give 3 examples of diseases caused by fungi
- black sigatoka
- ringworm
- athletes foot
black sigatoka
- organisms affected
- how does it spread
- affects banana plants
- spreads through spores
ringworm
- organisms affected
- how does it spread
- affects dogs + cats - it can pass to humans
- spreads via skin contact
athletes foot
- organisms affected
- how does it spread
- affects humans
- spreads via skin contact with infected skin / surfaces
outline the basic structure of protoctists
- single celled eukaryotes
- live in colonies
what type of protoctist are pathogenic
parasitic ones - these feed on living hosts
how do protoctists reproduce
binary fission
give 2 examples of diseases caused by protoctists
- malaria
- potato late blight
malaria
- organisms affected
- how does it spread
- affects reptiles + mammals + birds
- spreads through mosquito vectors - it affects RBCs, reproduces and bursts out
potato late blight
- organisms affected
- how does is spread
- affects potato / tomato plants
- spreads via spores
