Tuesday, August 23, 2016

1.Add to your table of contents:

2.Complete the bellwork and copy today’s

objective onto evidence #5.

Date Activity Evidence #

8/23/16 Food Webs/Energy

Transfer

5

Autotroph/Producer

Make their own food using the process of photosynthesis (converting sunlight and carbon dioxide into glucose and oxygen). All of the energy required to begin this process comes from the sun.

Autotrophs are also called Producers. All other organisms get their energy from producers. Without autotrophs, there would be no life on this planet

Ex. Plants and Algae

Heterotrophs

• Do not make their own food, but instead consume

other organisms to survive.

• Another term for Heterotroph is Consumer.

• Ex. Rabbits, Deer, Mushrooms

Heterotrophs - Consumers

1. Scavengers/Detritivores – feed on the tissue of dead

organisms (both plants and animals)

Ex. – Vultures, Crows, and Shrimp

Heterotrophs - Consumers

2. Herbivores – eat ONLY plants

Ex. – Cows, Elephants, Giraffes

Heterotrophs - Consumers

3. Carnivores – eat ONLY meat

Ex. – Lions, Tigers, Sharks

Heterotrophs - Consumers

4. Omnivores – eat

BOTH plants and

animals

Ex. – Bears and

Humans

Heterotrophs - consumers

5. Decomposers – absorb any dead

material and break it down into

nutrients found in the soil

**Decomposers can appear at any

point in a food chain whenever and

organism dies.

Ex. – Bacteria and Mushrooms

Food Chains

• Series of events in which one organism eats another and obtains

energy. Each level is called a “trophic level.”

• It involves one organism at each trophic level

–Primary Consumers – eat producers/plants and can be

omnivores or herbivores

–Secondary Consumers – a omnivore or carnivore that eats the

primary consumer

– Tertiary Consumers – eats secondary consumer; often called

the top of the food chain

Food Chains Draw the example on each level

of your food chain in your notes.

Trophic Levels

Energy moves from one organisms to another when it is

eaten

Each step in this transfer of energy is know as a trophic

level

Remember that all energy in an ecosystem originally

comes from the Sun. It begins each food chain.

Transfer of Energy

When a grasshopper eats the grass, it does not obtain all of the energy the grass has (much of it is not eaten)

When a snake eats the grasshopper, it does not get all of the energy from the grasshopper (much of it is lost as heat)

When a hawk eats the snake, there’s an even smaller amount of energy that’s transferred

Transfer of Energy

• These are examples of energy transfer that

show that no organism EVER receives all of

the energy from the organism they just ate

•Only 10% of the energy from one trophic

level is transferred to the next – this is called

the 10% law

Food Webs

•Most organisms eat more the JUST

one organism

•Several overlapping food chains in

an ecosystem make up a food

web.

Food Webs

Notice the direction the arrow points

The arrow points in the

direction of the energy

transfer, NOT “what ate

what”

Food Webs

Energy Pyramid

• An energy pyramid shows the relationship between consumers and producers at different trophic levels in an ecosystem

• Shows the relative amounts of energy or matter contained at each trophic level

• The Pyramid shows which level has the most energy and the highest number of organisms

Energy Pyramid

The amount of

available

energy and

the number of

organisms

decreases as

you move up

the pyramid.

M&M food chain game

1. You were given a card that states either Producers (or autotroph), Primary consumer (or heterotroph), or Predator (or secondary consumer).

2. Producers get 15 M&Ms.

3. Primary consumers must go around and take 6 M&Ms from two Producers (don’t take it from a producer that has already had 6 taken)

4 Predators must go around and take 3 M&Ms from three Primary Consumers (don’t take it from a consumer that has already had 3 taken)

M&M food chain game

Everyone should now have 9 M&Ms which are representing energy

Reflect on the following questions in your science notebook:

1. What happened to the amount of “energy” that transferred during each step?

2. In which step would it require the most energy to get the food needed for survival?

3. Which trophic level (producer, primary, secondary, or tertiary) is the most inefficient and why?