21-3 Interactions 21-3 Interactions Among Living ThingsAmong Living Things

o Every organism has a variety of Every organism has a variety of adaptations that are suited to its adaptations that are suited to its specific living conditions.specific living conditions.

o Adaptations are either physical, Adaptations are either physical, behavioral, or a combination of features behavioral, or a combination of features that allow organisms to successfully that allow organisms to successfully survive in their environmentssurvive in their environments

NichesNichesNiche:Niche: an organisms particular role an organisms particular role or how it makes its living or how it makes its living includingincluding its types of food, how it gets it, its types of food, how it gets it, what species use it for food, when what species use it for food, when and how it reproduces, and the and how it reproduces, and the physical conditions it needs for physical conditions it needs for survivalsurvival

The 3 Major Types of The 3 Major Types of Interactions BetweenInteractions BetweenOrganisms Organisms (competition, (competition,

predation,symbiosis)predation,symbiosis)

1.) Competition:Competition: the struggle the struggle between organisms to survive in a between organisms to survive in a habitat with limited resources. habitat with limited resources.

For example, on the savannah, For example, on the savannah, many organisms are herbivores many organisms are herbivores and compete with each other for and compete with each other for available forage (grasses, leaves, available forage (grasses, leaves, etc)etc)

3 Major Interactions 3 Major Interactions (cont.)(cont.)

* Many organisms develop adaptations to * Many organisms develop adaptations to avoidavoid competition. For example, some plants competition. For example, some plants produce toxins that retard the growth of other produce toxins that retard the growth of other plants, reducing competition with other plants plants, reducing competition with other plants for available resourcesfor available resources

2.) Predation2.) Predation:: an interaction an interaction where one organism hunts and kills another where one organism hunts and kills another for food.for food.There are There are twotwo types of types of predation adaptationspredation adaptations: : Predator adaptationsPredator adaptations and and Prey adaptationsPrey adaptations..Predator adaptations:Predator adaptations: adaptations that help adaptations that help them catch food like a cheetah’s speed (or them catch food like a cheetah’s speed (or claws) or the venom of a cobra.claws) or the venom of a cobra.

Predators and Prey

DinnerDinner!!!!!!

Run Away…Run Away…Run…Run Away…Run Away…Run…aghh !!!aghh !!!

Prey AdaptationsPrey Adaptations

Prey Adaptations:Prey Adaptations: these these are defensive adaptations are defensive adaptations that help an organism that help an organism avoidavoid predation. predation.

These include:These include:

Prey Adaptations

Camouflage :Camouflage : adaptations adaptations which help an organism blend which help an organism blend

into their backgroundsinto their backgrounds

Camouflage :(cont.)Camouflage :(cont.)

Warning Coloring:Warning Coloring: bright bright colors warn predators that these colors warn predators that these

organism are poisonous or noxiousorganism are poisonous or noxious

Mimicry:Mimicry: this strategy relies this strategy relies on making the organism appear on making the organism appear to be another more dangerous to be another more dangerous

oneone

Mimicry (cont.)Mimicry (cont.)

False Coloring:False Coloring: this adaptation this adaptation confuses or startles predatorsconfuses or startles predators

Protective Coverings:Protective Coverings: these make it difficult or painful these make it difficult or painful to prey on these animals so to prey on these animals so predators tend to avoid them.predators tend to avoid them.

3 Major Interactions 3 Major Interactions (cont.)(cont.)

3.) 3.) Symbiosis:Symbiosis: a close a close relationship between two relationship between two species that benefits at least species that benefits at least one species.one species.

There are at There are at threethree types of types of symbiotic relationships: symbiotic relationships: mutualismmutualism, , commensalismcommensalism, , andand parasitism.parasitism.

MutualismMutualismMutualism:Mutualism: a relationship where both a relationship where both species benefit species benefit ((bees and flowering bees and flowering plantsplants))..

Mutualism (cont.)

CommensalismCommensalism

Commensalism:Commensalism: a relationship where a relationship where one species benefits and the other is one species benefits and the other is neither helped neither helped nornor harmed (birds harmed (birds nesting in trees)nesting in trees)

ParasitismParasitismParasitism:Parasitism: a relationship where a relationship where one organismone organism-called the parasite--called the parasite- benefits by living on or inside benefits by living on or inside anotheranother-called the host--called the host- , harming , harming it. it. ((ticks, leeches, tapewormsticks, leeches, tapeworms).).

Parasites (continued)Parasites (continued)