parasites Flashcards
what do parasites do?
live on or in an organism (host) and obtain nutrients from the host and can survive in a host
causes harm to host
what are endoparasites?
live inside the host (like tapeworm)
what are ectoparasites?
lives on the host (like headlouse)
what are problems that gut parasites face?
lack of oxygen (anaerobic conditions)
extreme acidic/alkaline conditions
digestive enzymes
being washed away by food or juices
immune system of host
death of host
what is in the head of a tapeworm?
scolex
muscle
contains suckers and hooks
what is the body of a tapeworm like?
10m long
ribbon like
what is the life cycle of a parasite?
egg contaminated vegetation is ingested by livestock
eggs hatch into larvae and infect animals muscle tissue
larvae form cysts in muscle tissue
cysts survive in raw/undercooked meat which humans ingest
what are the primary and secondary hosts?
primary host is the human
secondary host is the livestock e.g. pigs
what is necessary for the survival of tapeworms?
way of penetrating the host and attaching to it
protection against hosts immune system
only develop organs which are essential for survival
produce large number of eggs
have an intermediate host
what are the structural adaptions of a tapeworm?
suckers and hooks
thick cuticle
simple structure
thin and long
male and female sex organs
lots of eggs produced
why do tapeworms have suckers and hooks?
for attachment to gut wall
why do tapeworms have a thick cuticle?
to prevent digestion by host enzymes
why do tapeworms have inhibitory substances on their surface?
to prevent digestion
why do tapeworms have a very simple structure?
to reduce energy and nutrients needed as cannot make their own
why are tapeworms very thing and long?
large surface area to volume ratio
for absorption of pre-digested food from host
