Block Day- January 12, 2012• Homework: study for…

• Food Web Checkup on Friday

Bell-Ringer: Two students were talking about grades. One student said “the purpose of test corrections is just to raise your grade.” The second student said “that’s true, you can improve your grade by doing test corrections but that’s not their only purpose.”

• What do you think the purpose of test corrections is—other than just raising your grade?

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• To learn the information. That is why you are required to explain why your answer was wrong and why the correct answer is right.

• To study for later tests. That is why you are required to write out the question.

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Make a logbook entry–

Food Chains and Food Webs-1/12/12

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Common Forest Organisms:

MillipedeSalamander

GarterSnake

Hawk

Big LeafMaple

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Food Chain

Millipede Salamander GarterSnake

HawkBig LeafMaple

Today’s objective:Using a food web to illustrate and analyze how energy flows through an ecosystem.

Food chain- A single pathway of energy transfer through an ecosystem as organisms eat one another.

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It’s all about ENERGY!

Arrows show direction of ENERGY flow:

NOT direction of eating:

Grass Cow

GrassCow

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Food Web• Insert the following organisms into your

diagram to convert your food chain into a food web:

Bullfrog

ShrewBanana

Slug

ClubMoss

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Food Web

Millipede Salamander GarterSnake

HawkBig Leaf

Maple

BananaSlug

Bullfrog

Shrew

Food CHAIN

Food WEB

ClubMoss

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Classifying organisms by energy intake

Producer- Gets energy from the sun.

Consumer- Gets energy from eating other organisms.

Herbivore- eats plants

Carnivore- eats animals

Omnivore- eats plants and animals

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Producers

• Place a capital P next to all the organisms that are producers in your food web.

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Food Web

Millipede Salamander GarterSnake

HawkBig Leaf

Maple

BananaSlug

Bullfrog

Shrew

ClubMoss

P

P

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Trophic levelsTrophic level- An organism’s position in

food chain. All organisms in the same position in a food chain are in the same trophic level.

Millipede Salamander Snake HawkMaple

Producer (1°) Primary/FirstConsumer

(2°) SecondaryConsumer

(3°) ThirdConsumer

(4°) FourthConsumer

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Primary, Secondary, Tertiary & Quaternary Consumers

• Place a “1°” next to any consumer that can act as a FIRST (primary) consumer…

• A “2°” next to any consumer that can act as a secondary consumer…

• A “3°” for third consumers…

• And a “4°” for fourth consumers.

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Food Web

Millipede Salamander GarterSnake

HawkBig Leaf

Maple

BananaSlug

Bullfrog

Shrew

ClubMoss

1°

1°

2°

2°

2°

P

P

2°3°3° 4°

1°

3°

4°

5°

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Biotic & Abiotic FactorsBiotic Factors – The living components

of an ecosystem.–Plants, animals, bacteria, etc.

Abiotic Factors– the non-living components of an ecosystem–Sunlight, Water, Temperature, Minerals,

Salinity (salt content), Space, Rocks/soil

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Abiotic Factor• Add the following abiotic factor to

your foodweb:

–Sunlight• NOTE: Use a different shape to show that

this factor is different from the previous biotic factors.

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Food Web

Millipede Salamander GarterSnake

HawkBig Leaf

Maple

BananaSlug

Bullfrog

Shrew

ClubMoss

1°

1°

2°

2°

2°

P

P

2°3°3°4°

1°

3°

LIGHT

5°4°

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ECOSYSTEMS

Ecosystems include both living (biotic) and non-living (abiotic) components

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•“FOODWEB PRACTICE”

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Organism What it eats

Painted Locust

Tree Daises

Hawk Mocking Bird, Snake

Scorpion Painted Locust

Tree Daises Not Applicable

Lava Lizard Painted Locust

Mocking Bird Painted Locust

Snake Lava Lizard

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• Draw a food web with the 7 organisms using arrows to show the direction of energy flow.

• Label the trophic level of each organism.

• Add 1 abiotic node and explain its effect/importance to your network

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TREE DAISIES

PAINTED LOCUST

LAVA LIZARD

SCORPION

SNAKE

MOCKING BIRD

HAWK

LIGHT

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TREE DAISIES

PAINTED LOCUST

LAVA LIZARD

SCORPION

SNAKE

MOCKING BIRD

HAWK

LIGHT

PRODUCER 1st

2nd

2nd

2nd

3rd

3rd

4th

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•10% RULE

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What causes the numbers of individuals in a population to decrease from producer to top level consumers?

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Graph of Energy Activity data

0

100

200

300

400

500

600

Grass

Cricke

ts

Frogs

Hawk

Un

its

of

En

erg

y

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Pyramid of energy example

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10% Rule in Ecology

• An average of only 10% of the energy in one

trophic level is passed to the next trophic

level.

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10% rule...

10%

90% lost as heat

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10% rule diagrams...

10%

90% lost as heat

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10% rule diagrams...

10%

90% lost as heat

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How much energy is at each level?

1000 Cal

? Cal

? Cal

? Cal

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How much energy is at each level?

1000 Cal

100 Cal

10 Cal

1 Cal

900 Cal as heat

9 Cal as heat

90 Cal as heat

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10% Rule

• Why do you think only 10% of the total energy from 1 trophic level is passed to the next?

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3 Reasons for decrease in available energy

1. Energy is “used up” for daily life activities.

2. Not all organisms that die are eaten by animals in the next trophic level.

3. Not all parts of an organism are eaten and digested for energy.

Conclusions about energy flow

1. How does the amount of energy change as it passes through an ecosystem? •The amount of available energy decreases as it passes to higher trophic levels

2. What is the source for all energy in an ecosystem?•All energy in an ecosystem can be traced back to the sun

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Make an entry- Matter Cycles- 1/13/12

• Tape in picture

• REMEMBER-

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