21-3 Interactions Among Living Things o Every organism has a variety of adaptations that are suited to its specific living conditions. o Adaptations are either physical, behavioral, or a combination of features that allow organisms to successfully survive in their environments

NichesNiche: an organisms particular role or how it makes its living including its types of food, how it gets it, what species use it for food, when and how it reproduces, and the physical conditions it needs for survival

The 3 Major Types of Interactions Between Organisms (competition, predation,symbiosis) Competition: the struggle between organisms to survive in a habitat with limited resources. 1.) Competition: the struggle between organisms to survive in a habitat with limited resources. For example, on the savannah, many organisms are herbivores and compete with each other for available forage (grasses, leaves, etc)

3 Major Interactions (cont.) * Many organisms develop adaptations to avoid competition. For example, some plants produce toxins that retard the growth of other plants, reducing competition with other plants for available resources 2.) Predation: an interaction where one organism hunts and kills another for food. There are two types of predation adaptations: Predator adaptations and Prey adaptations.  Predator adaptations: adaptations that help them catch food like a cheetah’s speed (or claws) or the venom of a cobra.

Dinner!!!

Run Away…Run Away…Run…aghh !!!

Prey Adaptations Prey Adaptations: these are defensive adaptations that help an organism avoid predation. These include:

Camouflage : adaptations which help an organism blend into their backgrounds

Camouflage :(cont.)

Warning Coloring: bright colors warn predators that these organism are poisonous or noxious

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

Mimicry (cont.)

False Coloring: this adaptation confuses or startles predators

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

3 Major Interactions (cont.) 3.) Symbiosis: a close relationship between two species that benefits at least one species.  There are at three types of symbiotic relationships: mutualism, commensalism, and parasitism.

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

Commensalism Commensalism: a relationship where one species benefits and the other is neither helped nor harmed (birds nesting in trees)

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

Parasites (continued)