“WHAT’S FOR DINNER?”

Energy Transfer andFeeding Relationships

Reminders and Take Notice!

Your lab is due on Monday, March 25. You and your partner will be marked on: proper arrangement of the write up completion of the lab in its entirety Your ability to reflect upon the observations made

based on the experiment you carried out

You will have your first quiz on Wed. March 27 Topics include 1. The Earth’s Spheres, 2. Biotic and

Abiotic features, and 3. Energy Consumption + Feeding Relationships

In other words, the first three slide shows, omitting adaptation

Feeding typesAnimals can be grouped in several ways. One way of doing this is based on how animals feed.

Consumers cannot make their own food. They must consume other organisms to get the food that they need.

Some organisms are producers. Producers make their own food.

Plants produce their own food using light energy from the Sun. Some types of bacteria can also make their own food by using light or chemical reactions.

Where does all the Energy in a food chain come from?

• Major source of energy for our planet

Provides energy used by green plants to make their own food in the process known as Photosynthesis

Plants provide food for other organismsAlso provides solar energy to generate

electricity, light energy and thermal energy to warm the planet and its inhabitants

How does the Energy get IN to the Food Chain?

PhotosynthesisExecuted by plantsA process by which plants take in the sun’s energy,

carbon dioxide and water to produce oxygen and stored energy upon which plants grow and survive

Carbon Dioxide + Water + Sunlight Sugar (energy) + Oxygen

CO2 + H2O + Sunlight C6H12O2 + O2

The reason photosynthesis occurs in plants and not animals is because it requires a chemical called chlorophyll

How do CONSUMERS USE this energy?

Cellular RespirationOccurs in animalsA process by which animals take in sugar

and oxygen to fuel the body while producing water and carbon dioxide

C6H12O2 + O2 CO2 + H2O + ATP

Complementary Processes

The product of one process equals the starting components of the other process

Types of Consumers

Herbivores: plant eaters (eg. Rabbit)

Carnivores: meat eaters (eg. Fox)

Omnivores: plant and meat eaters (eg. Bear)

Food chains – what eats what?

With the following groups, create a food chain, identifyingeach group member as a plant or animal.

**REMEMBER WHAT YOU WERE AND WHERE YOU FELL IN THE CHAIN.

Arctic 1CarolineEmmaMicaelaTatum

Forest 1PaulTristanJacob T.Luke

Pond 2JimDerekKeegan

Arctic 2Jo-AnnaHollyJulieKatie

Pond 1PatrickTonyStephen

Forest 2KarlyJillianMelissaSarah

Arctic 1NathanNick G.HennadiyNick R.

Forest 1MattKyleAlexZach

Arctic 2DavidOliverMadiLiv

PondRachelTashaMandyCindy

Forest 2AlecJacob M.Jacob R.Jacob B.

A food chain shows what is eaten by what. Each arrow means ‘eaten by’.

What does this food chain show?

A leaf is eaten by a caterpillar, which is eaten by a bird, which is eaten by a cat.

Energy is transferred from one organism to another in the direction of the arrow

Food chains

leaf caterpillar bird cat

Food chains – activity

Green plant Goat Owl Rabbit

Mouse Wild Cat Snake Eagle

Lion Jackal (like a wolf)

A food chain can be used to rank different types of consumers.

Ranking consumers

producers – make their own food;

primary consumers – eat producers;

secondary consumers – eat primary consumers;

tertiary consumers – eat secondary consumers.

humancrayfishlimpetseaweed

producerprimaryconsumer

secondaryconsumer

tertiaryconsumer

Do animals only eat one species??

Food chains show simple relationshipsFood webs show all the feeding relationships

in a habitat

Which of these organisms are producers?

Which ones are Herbivores?

Which ones are carnivores?

Which ones are omnivores?

Build a food web

Nuts Mice Wolf BearNuts Deer Wolf BearBark Rabbit Wolf BearBlossoms Insects Birds Red fox BearBlossoms Bees BearBark Rabbit Red fox Bear

Food Pyramids

We draw food webs to show how animals’ eating habits are related

We draw pyramids to show how energy (biomass) is passed along from one animal to the next

What shape is a pyramid? What can the shape tell us about energy at the

top?

What is Biomass?

The total dry mass of living organisms in a group or area

Example:

How do we measure the biomass for field of grass? (producer level on our food chain)

Dry the grass then take the mass of it

= biomass of the grass

Biomass tells us how much Energy is available to the next trophic level

Why do we take the water out when we measure biomass???

Example: What has more energy?Watermelon Bread

Two Types of Pyramids

1) Pyramid of Numbers Count number of each organism Not as accurate Example: 1 oak tree, 10 caterpillars, 2 birds

 

 

 

Blackbird

Oak Tree

Caterpillar

Types of Pyramids

2) Pyramid of Biomass Weigh all the organisms at each stage of the

food chain (biomass of producers > consumers) More accurate to show feeding relationshipExample: even if there is only one oak tree it can have many caterpillars living from it

 Oak Tree

  Blackbird

 Caterpillars

Food Pyramids and Energy

Only about 10% of the energy from one level gets passed to the next

Reasons why biomass decreases as you go up the pyramid:

Not all of the plant is eaten by herbivores (only eat leaves, not roots)

Not everything eaten is digested (wolf eats a deer, uses meat but fur is waste)

Energy is lost in the form of body heat, used for activity, to carry out life processes

Example: When we eat chicken for dinner we do not get 100% of the energy from it. Why?

Eating lower on the food chain wastes less energy

Animals need energy to live, grow and reproduce

Animals get less energy from what they eat if at the top of the food chain

This can explain why there are usually fewer carnivores than herbivores, and fewer herbivores than plants

Grass

Rabbit

Eagle

Practice Calculation for Energy Transfer

Calculate the units of energy in each trophic level of the food chain below. Remember that only 10% of the energy gets passed along.

(Starting energy units) x (0.10) = Energy passed along

(2543) x (0.1) = 254.3 units of energy (grasshoppers)

(Starting energy units) x (0.10) = Energy passed along

(254.3) x (0.1) = 25.43 units of energy (spotted frog)

TRY THE NEXT STEP ON YOUR OWN!

(25.43) X (0.1) = 2.543 units of energy (red-tailed hawk)

(Starting energy units) x (0.10) = Energy passed along

Answer:

Hint: Every trophic level you move up in the food chain, you move the decimal over one place to the left (This is 10% of the starting number)

254.3 energy units

25.43 energy units

2.543 energy units