Flashcards
Microbes and Disease
Cards in this deck (12)
- 1List the pathogens.- viruses
- bacteria
- fungi
- protists
- some multicellular eukaryotes e.g. helminths
- host-derived infections - 2Describe the actions of bacteriophages.- lytic = adsorbed, inject DNA, transcribe and replicate, lyse
- hide in genome without killing them
- can become part of accessory genome
- complex role in ecology and evolution
- most abundant organisms - 3What is the general rule for host-to-host transmission?- one infection must give rise to at least one other
- not all infections are beneficial = some come from failed commensal relationship
- if fewer descendants are produced it will die out - 4Describe the key features of chlamydia.- great extent of recombination = escape Mueller's ratchet
- small streamlined genome = metabolic specialisation
- obligate intracellular pathogen - 5Describe the different types of transmission.- horizontal = host-to-host
- vertical = parent to offspring - 6What is host immunity?- removal from transmission system
- certain during of protection - 7Describe the key features of measles.- highly infectious by respiratory route
- no other known reservoir
- lifetime immunity
- can only persist in populations of a certain size - 8Compare acute and chronic infections. Give examples.- acute = vulnerable to excess host death or immunity
- chronic = dormant then reactivated
- e.g. chickenpox and shingles - 9What are zoonotic diseases? Give examples.- pathogens that infect multiple host species
- some dead end hosts
- novel infectious cycles can arise
- complex multi host transmission cycles
- rabies, TB, schistosomiasis - 10What are the advantages and disadvantages of zoonoses?- pathogen takes advantage of on host to infect another
- enables infection, generates reservoir, promotes spread
- costly = survival in different environments, evading different immune responses - 11What are infectious cancers? Give examples.- cancer cells that spread
- caused by viruses and bacteria
- direct or indirect effect of transmission
- e.g. HPV, DFTD (Tasmanian devils), CTVT (dogs) - 12What are prions?- infectious protein agents
- naturally present
- autocatalytic conversion to pathogenic form
- no genetic material
- highly resistant
- cause transmissible spongiform encephalies (scrapie, BSE)
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- Prelims Organisms Flashcards on Microbes and Disease, created by Kirstin Latimer on 08/01/2016.
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- Kirstin Latimer
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