Transcript ORGANISMS CAN INTERACT IN DIFFERENT WAYS

ORGANISMS CAN
INTERACT IN DIFFERENT
WAYS
• ORGANISMS INTERACT IN
DIFFERENT WAYS
• SURVIVAL OF ONE SPECIES MIGHT
DEPEND ON ANOTHER SPECIES
– SYMBIOSIS = relationship between
individuals of 2 different species who live
together in a close relationship (word means
“living together”)
• INTERACTIONS IN AN ECOSYTEM
ARE COMPLEX
Organisms Interact in Different
Ways
• PREDATOR/PREY: predator is an animal that eats
another; prey is an animal eaten by a predator; in a food
chain, an animal may be both(a small bird feeds on
grasshopper, then is eaten by a falcon).
• The sick & elderly usually are the members of a
population that are eaten; prey may affect the location of
predators (birds will go where the insects are).
• COMPETITION: struggle between individuals or
different populations for a limited resource.
• Competition may occur within same species (plants
compete for light & nutrients) or different species
(strangler fig vines compete with trees for water light &
nutrients, eventually killing it).
Organism Interactions Con’t.
• COMPETITION CON’T.: occurs between & within
species (vultures & hyenas compete for remains of dead
animals- wolves compete with each other over territory);
within species competition often occurs during mating
season. Many populations can coexist in a habitat without
competition also (maple, beech, & birch trees side by
side).
• COOPERATION: an interaction in which organisms
work in a way that benefits them all. (some predators
hunt in packs- killer whales, lions, wolves, etc.)
• Ants, bees, & termites are social insects; members of a
colony belong to different groups called castes & have
different responsibilities (gather food, defend colony)
• Apes & monkeys live in family groups, & members
cooperate to take care of the young.
Organisms Interacting
Survival of 1 Species may
Depend on Another
• Symbiotic Relationships: both species benefits, 1
benefits & other isn’t affected, & 1 benefits while
other is harmed.
• MUTUALISM= interaction between 2 species
that benefits both. (bee gets nectar from flower,
& flower gets pollinated).
– Many plants rely on mutualism to reproduce
(insects & birds get nectar & in turn pollinate,
or animals eat fruit & disperse seeds).
– Mutualism might be necessary for survival of
organism (termites live off of wood because
have one-celled protozoa making homes in
their gut and they digest the wood into usable
nutrients).
Species Survival con’t.
• COMMENSALISM: relationship between 2 species
where 1 benefits & other is unaffected. Orchids &
mosses grow on trees to get light & nutrients that run
down along tree, tree remains unaffected.
• Commensal relationships common in ocean
ecosystems (remoras stick to sharks to eat scraps
leftover; fish swimming among jellyfish tentacles for
safety).
• PARASITISM: one species benefits while other is
harmed. Parasites (ticks, lice, mites) feed off &
weaken their hosts. Tapeworms & ringworms are
internal parasites living inside of host.
– Nest or Brood Parasitism= female cowbird lays
eggs in a warbler’s nest, often pushing out warbler
eggs.
Species Survival Relationships
Complex Interactions in Ecosystem