Download Interactions Among Living Things

Interactions Among Living Things
1. Symbiosis
Symbiosis occurs when two species live together in a close long-term
association.
In a symbiotic relationship at least one of the organisms involved is meeting one
of the basic needs for living through the relationship.
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Mutualism – a symbiotic relationship in which both participating
species benefit.
Ex: Ant & Aphid – the ant gets nutrition from the apid’s
honeydew- a sugary secretion from the aphid’s body. The aphid
gets protection from the ant against predatory insects like
ladybugs.
Commensalism – A symbiotic relationship in which one organism
benefits and one is neither harmed nor helped.
Ex: Epiphytes also known as “air plants” live on the bark of trees.
The epiphyte gets space to live and the tree is not harmed nor does
it benefit in any way.
Parasitism – a relationship in which one organism feeds on and
usually lives on or in another.
Ex. – tape worm – a tape worm lives inside the animals intestines
and gets shelter and food. The animal looses nutrition, may loose
weight and become ill.
2. Predation
Interaction in which one organism kills another for food.
 Predator – organism that hunts and kills the other organism for food
 Prey – organism being hunted and killed
Benefits of predation: predator gets food, prey population is kept under control.
Adaptations: certain adaptations help the predators catch their prey, adaptations help
prey hide from predators
Defense Strategies:
 Mimicry – pretending to be a more terrifying animal
 Camouflage – hiding in the surroundings, matching the environment
 Warning Coloring – color is a signal that the prey is poisonous
 False Coloring – coloring and design looks like a larger, scarier predator
 Protective Covering – organism protects itself with a harder outer shell or outer
covering
3. Competition
The struggle between organisms to survive as they attempt to use the same
limited resources.
 There is a limited amount of food, water and shelter
 Organisms that survive have adaptations that enable them to reduce competition.
 Different species can share the same habitat and food requirements but if two
species occupy the same niche, one of the species will eventually die off.