Aim: How do organisms interact in an ecosystem?

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 st Order Herbivore 2 nd Order Carnivore/ Omnivore 3 rd Order Carnivore/ Omnivore Herbivores – eat only producers Carnivores – eat only meat Omnivores – eat both producers & meat

Ecosystem Relationships: Symbiotic Relationships 1.Parasitism – parasite benefits and host is affected negatively (+, -) ex. Tick and human 2.Mutualism – both benefit (+, +) ex. Bee and flower. 3.Commensalism – one benefits and other is unaffected (+, 0) ex. Whale and barnacle 4.Predator & prey – predator benefits and prey is affected negatively ex. Rabbit and lynx.

Parasitism: Fluke Worms Tick Parasites are organisms that attack other live organisms called hosts.(+,-)

Mutualism: 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.

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___________. ___________capture this energy through a process of _________________ sun Autotrophs photosynthesis

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

In which direction is the energy moving? Why? Energy transfer

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 1st Order Consumers 2 nd Order Consumers 3 rd Order Consumers Energy Flow

Sun’s Energy in an Ecosystem Some of the energy is used by each organism and some of it is lost 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% 90% LOST!

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. Energy Pyramid Shows the relative amount of energy available at each trophic level. Section 3-2 Ecological pyramids Go to Section:

In which direction is energy flowing?