Ecology Flashcards
what is ecology?
the study of interactions of living organisms with their environment
levels of classification?
individual
assemblage
community
ecosystem
what must a limiting resource be?
scarce and important
what must there be for species to coexist?
stronger intraspecific comp than interspecific
what is interspecific competition?
competition of different species for the same resource
what is intraspecific competition?
competition between individuals of the same species
what happens as populations grow?
they continue to grow until limiting resource where plataues and the population stops growing
what are the three forms of competition?
exploitation, pre empitive and interference
what is exploitation?
ability of species to use a limiting resource so the competitor cannot
What is interference?
actively reducing competitor acess to limiting resource
what is pre-emptive competition?
interface between exploitation and interference
prevent others using the resource e.g giant amazonian water lillies
what is parasitism and give example?
host harmed and symbiont benefits
eg corpse lily - once flowers kills host
whats commensalism?
host unaffected symbiont benefits - clown fish and anemone
what is mutualism?
both species benefit e.g wrasse fish and parrot fish
what happens during coral bleeching?
occurs when stressed and they expel zooxs which either causes the coral to die or replace the algae
what is the relationship between coral and zooxanthelae?
obligate symbiosis
corals need zooxs to survive, zooxs eat algae
what do you call the symbiont when its outside the host and inside?
in - endosymbiont
out - ectosymbiont
what is coral bleaching and the problems on lizard island?
cyclones, bleaching event - a break up of symbiosis
forms of physical defence against herbivory?
crypsis
spines
colour
raphites
forms of chemical defence against herbivores
traits to attract predators
secondary metabolites
what does nitrogen do?
affects nerve transmission so changing behaviour - caffine, morphine
glucosinolates - interferes with digestion -painful - comes from poison in heavy metals e.g cyanide in apple seeds
what do terpenoids do?
toxic
volatile organics
eg methanol or citronella
what do phenolics do?
e.g graoes
inhibt digestion by interfering with protein absorption
adaptations for herbivores?
parrot fish - strong jaw
monarch butterfly eat milkweed makes them poisonous
sea slugs eat everything and get energy from alage
koalas eat eucalyptus which is poisonous but have bacteria that can break down toxins so feed babies poo so they get the bacteria too
why are herbivores important for the ecosystem?
determines level of nutrients
what do sea urchins eat?
algae so bloom in algal bloom
adaptations for avoiding predation?
physical - giant clam strong jaw that closes when it senses movement
chemical - aposematism
masquerade
camo
behaviour - fruit bats only fly at night and rabbit fish swim in pairs so one can look out and the other can eat
adaptations for predators?
speed
strength
camo
senses - Bajau adapted eyes, spleen and feet for living in water
ingestion of prey - starfish cant break through exoskeleton of coral so extract stomach and ingest it
cooperation - octopus and coral trout
biggest predator?
humans
what is the predator-prey cycle?
populations roughly the same but slightly offset - prey one step behind
prey>predator
when lots of prey predators increase
whats important in the predator-prey cycle?
must always be equilibrium
whats the model for predator-prey cycles?
lotka-volterra
equations for lotka-volterra?
dH/dt = rH - alphaHL dL/dt = betaHL - dL where r = growth rate alpha = rate predation beta = probability of prey capture H = size of inital pop HL = size lynx pop dL = probability of death
equilibrium reactions for predator-prey cycle?
Leq = r/alpha Heq = d/beta
whats the temp range organisms survive in?
122 - -2
what happens to organisms when its too cold
freeze and cell membranes destroyed
or freeze instantly
at -50 some organisms can survive but dormant/can’t reproduce
whats special about lake Vostok?
analogue
2.2 miles under ice
if things can live here probably can live in space too
factors influencing climate change?
invasive species extinctions over exploitations collapsed fish stocks eutrophications
what is a homeotherm?
organism with small openings to conserve heat
whats a poihilotherm?
organism capable of varying internal temp within a range to reproduce/grow
what is important about chemiosynthesis?
means life can live in the dark
example of an organism with antifreeze properites?
atlantic cod
what is bergmanns rule?
the larger the organism the smaller the surface area for heat to be lost from
