Do Now

In 1-2 sentences on the next open left hand page:

Why do you think competition between organisms occur?

Teaching Point

SWBAT:

1) Explain what a niche is2) Differentiate the three types of symbiosis

NicheEvery species has a habitat where it can live and occupy. An organism is adapted to its habitat and the environmental conditions in it. Organisms within a habitat usually occupies and interacts within a specific section or part of the habitat. This is the organism’s niche.

Niche

A niche not only describes what an organism does, but also how it interacts with biotic and abiotic factors in the environment. Resources, or necessities of life, are found within an organism’s niche.

Competition In nature, different organisms are all fighting to use various essential resources. When organisms attempt to use the same limited ecological resource in the same place at the same time, competition occurs. Whenever two organisms have competition, there is always a winner and a loser-and the losing species dies out.

Competition

The competitive exclusion principle states that no two species can occupy exactly the same niche in exactly the same habitat at exactly the same time. Species avoid competition by dividing resources.

Competitive Exclusion Theory

Predator-Prey

In nature, some animals eat others. When one animal (the predator) captures and feeds on another animal (the prey), predation occurs. Predators can affect the size of prey populations in a community and determine the places prey can live.

Herbivory

When an animal (the herbivore) feeds on producers (such as plants), herbivory happens. Herbivores can affect both the size and distribution of plant populations in a community and determine the places that certain plants can survive and grow.

Keystone Species When certain species, called keystone species, increase or decrease, they cause dramatic changes in the structure of a community.

SymbiosisAny relationship in which two species live closely together is called symbiosis.

Mutualism

•Both organisms benefit

•Ex:

•Clown fish and Sea Anemone

•Acacia Trees and Ants

•Water Buffalo and Birds

Parasitism

•When one organisms benefits and the other is

harmed (+/-)

•Ex:

•Tapeworms and Mammals

•Malaria

•Ticks and Mammals

Commensalism

•One organism benefits while the other is neither

helped nor harmed

•Ex:

•Whales and Barnacles

What Now1) Work on the Guided Practice individually or

with a partner

2) When finished, let a teacher know and stamp your work

ClosureAnswer the following question underneath your Teaching Points:

If two species of birds both live in the same habitat and eat the same fruit at the top of a tree at the same time, will both species be able to live together? Why?