Let’s Review Put the following in order from Largest to smallest: Community BIOSPHERE Organism Ecosystem Population

Organism Interaction Organism in an ecosystem must interact with each other and the environment in order to ensure their survival. Organisms have a role to play in their ecosystem.

Interactions with Environment Natural selection – When nature selects the best characteristics suited for the environment. These characteristics are passed down to the offspring (children). Natural selection results in adaptation

How does natural selection work? Individuals best suited for the environment will survive and produce offspring. The offspring will inherit this characteristic and pass it to their offspring. Ex. Long neck giraffes and short neck Giraffes Green Alligators and albino Alligators

Every organism has a variety of adaptations that are suited to its specific living conditions. Niche – The role of an organism in its environment. A niche can include: The type of food an organism eats How an organism obtains food The which organisms use that organism for food

Interactions Between Organisms There are three major types of interactions among organisms: Competition, predation and Symbiosis

Competition- The struggle between organisms as they attempt to use the same limited resource. If two organisms share the same niche, one will eventually die off Adaptations reduce the need for competition. Ex. Birds and bats Roadrunner and Elf owl

Predation Predation – When one organism kills another for food. The organism that does the killing is called the predator. The organism that is killed is called the prey.

Predation and population size As the number of predators go up, the population of the prey will go down. Since the number of prey has gone down predators will begin to die. This causes the prey population to increase once again.

Predator Adaptations Predators have adaptations that help them catch and kill prey. Ex. Cheetahs can run very fast. Jellyfish tentacles hang and contain poison. Sundew plant has a sticky substance that catches flies when they land

Prey Adaptations Prey have adaptations that protect them from predators. Mimicry – To look like a more dangerous animal Warning Colors – Bright colors let predators know that the organism is poisonous Camouflage – Prey can easily hide from predators

Symbiosis Symbiosis – A close relationship between organisms in which at least one will benefit Three Types: Mutualism Commensalism Parasitism

Mutualism – Both organisms benefit Bacteria in your stomach – Bacteria gets protection from you. The bacteria help you digest vegetables

Commensalism – One species benefits and the other is neither helped nor harmed

Parasitism – One organism living on or inside an organism and harming it. Parasites can live inside the host or on the surface of the host.

Parasitism The organism that benefits is called the Parasite. The organism it lives on or in is called the host. Parasites normally do not kill their host. If they kill their host, they lose their source of food.