LO: How do organisms interact in an ecosystem? DN: What is a niche? Can two organisms occupy the same exact niche? Explain. HW: textbook page 85#19-22

Why do organisms need to eat? To get ENERGY!! Cell Respiration: C 6 H 12 O 6 + O 2 ATP + CO 2 + H 2 O

Organism Categories: Organisms Producers (Autotrophs) Consumers (Heterotrophs) Decomposers

Organism Categories: Consumers 1’ Consumers Herbivore 2’ Consumers Carnivore/ Omnivore 3’ Consumers Carnivore/ Omnivore Herbivores – eat only producers Carnivores – eat only meat Omnivores – eat both producers & meat

Ecosystem Relationships: Symbiotic Relationships 1.Mutualism 2.Commensalism 3.Parasitism 4.Predator & prey

Parasitism: Fluke Worms Tick Parasites are organisms that attack other live organisms called hosts. parasite benefits and host is affected (+, -)

Mutualism: both benefit (+, +) The Nile crocodile opening its mouth to permit the Egyptian plover to feed on any leeches attached to its gums. Bee eats nectar & at the same time picks up pollen to be spread to other flowers.

Commensalism: Barnacles are non-motile, & they adhere to the fins of whales. This allows them to be taken to places where there is food. The whale is not affected. one benefits and other is unaffected (+, 0)

Predator & prey – predator benefits and prey is affected

How do the cows we eat get their energy? Primary consumers get their energy from the producers they eat

How do producers get their energy? The primary source of energy for living things is the sun. Autotrophs capture this energy through the process of photosynthesis

How is energy transferred in a community? Energy is transferred by consuming other organisms

In which direction is the energy moving? Why?

Scientists depict this transfer of energy as a Food chain. They show the transfer of energy from one organism to another in a community Food Chains

Food Webs Show many food chains interconnected together

Energy Pyramid Producers 1’ Consumers 2’ Consumers 3’ Consumers Energy Flow

Sun’s Energy in an Ecosystem Some of the energy is used by each organism and some of it is transferred as heat energy to the environment

Why is there so little energy at the top of the pyramid? Most of the energy from the sun has been used or lost by organism in the lower levels Only about 10% of the energy available at each level is transferred to the NEXT level. 100% 10% 1%

Pyramid of Numbers Shows the relative number of individual organisms at each trophic level. Biomass Pyramid Represents the amount of living organic matter at each trophic level. Typically, the greatest biomass is at the base of the pyramid. Energy Pyramid Shows the relative amount of energy available at each trophic level. Organisms use about 10 percent of this energy for life processes. The rest is lost as heat. Ecological pyramids Go to Section: