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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”)
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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.
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.