2.5 parasitism Flashcards
(56 cards)
how can endoparasites evade the immune system?
by mimicking host antigens to evade detection and modify the host immune responseto reduce their chances of destruction
what are some methods for parasite control?
civil engineering projects to improve sanitation (latrines, wells)
vector control (pesticides)
what must be reflected in the design of the vaccine?
antigenic variation
which enzymes, found in mucus, saliva and tears, and involved in the breakdown of bacterial cell walls?
hydrolytic enzymes
what does the parasite become part of by altering the host?
its extended phenotype
what can parasites do to the host to benefit its growth, reproduction and transmission?
suppress the host immune system and modify host size and reproduction rate
what can parasites alter about the host to maximise transmission?
host foraging, movement, sexual behaviour, habitat choice and anti-predator behaviour
which two factors increase transmission rates of a parasite?
overcrowding of hosts when they are at a high density
mechanisms such as vectors and waterborne dispersal stages (allow the parasite to spread even if infected hosts are incapacitated)
which two aspects of a parasite’s biology must we understand?
transmission - how they spread
virulence - the degree of harm they cause their host
what happens once a retrovirus has formed DNA?
it is inserted into the genome of the host cell
what are the stages of the viral life cycle?
host infected with genetic material
host cells replicate viral genome
viral genes and proteins transcribed and translated
new viral particles assembled and release
what can be found on the outer surface of a parasite?
antigens that a host cell may or may not be able to detect as foreign
what are some viruses surrounded by?
a phospholipid membrane derived from host cell materials
in which form do viruses contain genetic material?
of DNA and RNA, packaged in a protective protein coat
what happens second in the plasmodium life cycle?
red blood cells burst and gametocytes are released
what is fundamental niche?
the niche that it occupies in the absence of any interspecific competing influences
how can some viruses escape immune surveillance?
they can integrate their own genome into the genome of the host, remaining inactive until they are needed. this is called latency
what does antigenic variation allow?
the parasite to change between different antigens whilst affecting the host, which can allow for re-infection
what will improving parasite control help with?
reducing child mortality rates
improving child development and intelligence due to greater access to resources
what do the conditions in refugee camps mean for the coordination of treatment programmes?
they are difficult to achieve
what can refugee camps result from?
war, natural disasters or over-crowing cities in less economically developed countries
which conditions can cause parasites to spread more rapidly?
overcrowding and tropical conditions
what gives antibodies specificity to binding antigens?
they possess regions where the aminoacid sequence varies greatly betweendifferent antibodies
why can it be difficult to produce a vaccine against parasites?
they can be difficult to culture in a lab
