AS SOON AS YOU ARE SEATED...AS SOON AS YOU ARE SEATED...

Above is an image of a Food Chain. Using the words below as a guide, write a passage outlining everything you have learned about food chains. Do Not Use Your Notes. I will collect these

to gauge the success of last week’s lessons.

Autotroph, Primary Producer, Secondary Consumer, Trophic Level, Top Predator, Sunlight, Decomposer,

Energy Transfer, 10%

Energy Flow Through Ecosystems…A REVIEW

Ecosystem and Energy Roles

Ecosystem: all living & non-living things that interact in an environment

Energy Role in an Ecosystem Determined by:

How it obtains energy How it interacts with other living organisms in its

ecosystem

Some Energy Roles

The sun: provides energy Producers: harness energy from the sun

ex. plants Consumers: organisms that eat something

else ex. animals

Decomposers: return energy to the environment ex. fungus, bacteria

Producers

Plants harness energy from the sun through photosynthesis

They are the base of every food chain Source of food for all other animals

Consumers

4 Types Herbivore: eats only plants

Ex. Cows, horses Carnivore: eats only meat

Ex. Polar bear Onmivore: eats plants and animals

Ex. Humans, grizzly bears Scavenger: carnivore that feeds on bodies of

dead organisms Ex. Vultures

Decomposer

Decomposers break down wastes and dead organisms and return the raw materials to the environment Ex. Bacteria, fungi

Energy flow through biological systems

Food Chains

Food Chain: series of events in which one organism eats another and obtains energy

Food Chains Continued

Arrows always points in the direction of energy flow

1st organism is always the producer

2nd organism is the consumer that eats the producer Primary consumer

3rd organism is the consumer that eats the 1st level consumer Secondary consumer

And so on…..

Laws of Thermodynamics!!

Knowledge Check!!

You are a green plant that just created 5,000,000 kJ of energy through

photosynthesis. OH NO!! You’ve just been eaten by a field mouse. OH NO!! Now, the

mouse has been eaten by a fox. OH NOOO!! The fox has been eaten by a wolf.

How many kJs of energy did the mouse, fox, and wolf receive?

Knowledge Check!!

MOUSE: 500,000 kJ FOX: 50,000 kJ WOLF: 5,000 kJ

Now...

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1st Law of Thermodynamics

Energy cannot be created nor destroyed, but can be transformed from one form to another.

The amount of energy in the universe is constant.

Approx. 99% of energy on Earth available for living organisms comes from the Sun.

2nd Law of Thermodynamics

During any energy transformation, some energy is converted into unusable energy or is lost.

No energy transformation is ever 100% efficient.

Ecological Pyramids!!

Ecological Pyramids

Can be used to represent energy flow or matter in food chain and food webs.

Are based on the idea that, due to energy loss, fewer organisms can be supported at each additional trophic level in a food chain.

1. Pyramid of Biomass

Shows the total mass of living tissue at each level.

Biomass: the total dry mass of all of the living material in an ecosystem.

2. Pyramid of Numbers

Shows the number of organisms at each trophic level.

Number of organisms decreases as we move up the pyramid.

3. Pyramid of Energy

The amount of energy at the pyramid bottom is fixed by the amount of photosynthesis that occurs.

Most of the energy at each level of a food chain is lost as heat (90%) which means that only 10% of energy is useful and is passed onto the next level.

Sample Energy Pyramid