AGENDA TAKE OUT NOTEBOOKS BELLRINGER LEVELS OF ORG

AGENDA • TAKE OUT NOTEBOOKS BELL-RINGER: LEVELS OF ORG FOOD CHAIN NOTES FOOD CHAINS PRACTICE (WITH A PARTNER) WORD WALL

Bell-ringer: For each numbered picture write which level of organization it represents and WHY. 1 2 3 4

Today’s Objective: • Be able to explain energy transfers among organisms using food chains and food webs.

• The ultimate source of the energy for life is the sun.

The Producers: Autotrophs • An organism that uses light energy (mostly plants) to make food is a producer, or autotroph. • Autotrophs are our link to the energy from the sun. All other organisms depend on autotrophs.

• Autotrophs use the sun’s energy to manufacture food energy in a process called photosynthesis

The Consumers: Heterotrophs • An organism that cannot produce it’s own food energy and has to eat/consume other organisms for energy is a heterotroph. • There are different types of heterotrophs.

The Consumers: Heterotrophs • A heterotroph that feeds only on plants (autotrophs) is an herbivore.

The Consumers: Heterotrophs • Some heterotrophs just eat other heterotrophsthese are carnivores.

The Consumers: Heterotrophs • Some heterotrophs eat both heterotrophs and autotrophs. They are called omnivores.

The Consumers: Heterotrophs • Scavengers eat animals that have already died. • They don’t actually kill for food, but they only eat dead heterotrophs

The Consumers: Heterotrophs • Some organisms, such as bacteria, fungi, and some worms are decomposers. • Decomposers break down the complex compounds of dead and decaying plants and animals into simpler molecules that can be more easily absorbed/recycled.

The ultimate source of energy is……. This energy goes to…… Autotrophs

How do heterotrophs get their energy? By eating autotrophs…. . And by eating the heterotrophs that ate autotrophs…. .

Who do you think is getting more energy?

• Food energy flows through an ecosystem from producers to consumers in a chain… • Matter (like water and carbon) gets recycled. • Energy does not…. it changes and is replenished everyday by the sun.

• A food chain is a simple model that scientists use to show energy moves through an ecosystem. • In a food chain, nutrients and energy move from • autotrophs to • heterotrophs and, eventually, to • decomposers.

The Flow of Matter and Energy FOOD CHAINS • The arrows in a food chain show the direction of ENERGY FLOW. berries → mice → black bear • Most food chains consist of only two, three, or four transfers.

The Flow of Matter and Energy FOOD CHAINS berries → mice → black bear 1000 kcals 10 kcals • Only about 10% of the energy is transferred at each feeding step…. . This is why a bear would have to eat a lot of mice….

• If only 10% is transferred to the consumer, what happens to the rest of the energy? LEFT BEHIND AND GIVEN OFF AS HEAT ENERGY

• Each feeding step in a food chain is called a trophic level.

• The first CONSUMER in a food chain is called a primary or first-order heterotroph. • The first-order heterotroph eats autotrophs.

• A second order heterotroph is an organism that feeds on a first order heterotroph.

• A third order heterotroph or tertiary is an organism that feeds on a second order heterotroph. • REMEMBER: a food chain represents only one possible route for the transfer energy through an ecosystem.

Food Chain Food Web How would you explain the difference between a food chain and a food web?

• Unlike a food chain, a food web, shows ALL the possible feeding relationships at each trophic level in a community.

In a food web, there can be more than one autotroph, and there can be more than one consumer at each trophic level. How many first order heterotrophs are there in this food web? Which organism is both a first and second order heterotroph?

• An ecological pyramid is another way to show a food chain. 1. The autotroph is always at the bottom of the pyramid 2. As you go up the pyramid, you go higher in the trophic levels Fox (1) Birds (25) Grasshoppers (250) Grasses (3000) This pyramid is a pyramid of NUMBERS.

This pyramid shows ENERGY LOSS. Pyramid of Energy Heat 0. 1% Consumers 10% Consumers Heat Pa r dec asit lev omp es, s el. ose cav rs eng fee ers da , a t e nd ach 100% Producers