Welcome back! Consider the following:

Identify the

following:

1. Producer

2. Secondary

Consumer

3. Tertiary Consumer

4. Quaternary

Consumer

5. Any Higher?

Question of the day?

Food Chain?

Simplistic view of

energy flow

Linear path

Lacks other possible

pathways energy

can be passed.

Food Web?

Realistic view of

energy passage.

Combines food

chains.

Energy Pyramid

Primary

Producer

Primary

Consumer

Secondary

Consumer

Tertiary

Consumer

Quaternary

Consumer

Energy Pyramid

Primary

Producer

Primary

Consumer

Secondary

Consumer

Tertiary

Consumer

Quaternary

Consumer

100,000 J

(Joules)

1 J (Joules)

10 J (Joules)

1,000 J (Joules)

100 J (Joules)

10,000 J

(Joules)

Energy Pyramid: 10% Rule

Primary

Producer

Primary

Consumer

Secondary

Consumer

Tertiary

Consumer

Quaternary

Consumer

100,000 J

(Joules)

1 J (Joules)

10 J (Joules)

1,000 J (Joules)

100 J (Joules)

10,000 J

(Joules)

10% Rule

As energy passes through each trophic level only 10% of the

energy is passed on.

The remaining energy is lost as “heat”.

10% rule...

10%

1010% rule diagrams...

10%

1110% rule diagrams...

10%

12 How much energy is at each level?

1000 Cal

? Cal

? Cal

? Cal

13 How much energy is at each level?

1000 Cal

100 Cal

10 Cal

1 Cal

14

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.

Negative Feedback = The way living systems maintain

homeostasis.

Homeostasis =The property of a system, that regulates its

internal environment and tends to maintain a

stable, constant condition.

Negative feedback systems include a sequence of events that

will cause an effect that is in the opposite direction to the original

stimulus and thereby brings the system back to its equilibrium

position.

Predator Prey relationships are usually controlled by

negative feedback where:

Increase in Prey Increase in

Predator Decrease in Prey

Decrease in Predator Increase in Prey and so on in a

cyclical manner

Question of the day?

Answer

There is not enough energy to maintain

organisms at the top of the food chain.

Energy is consumed by prior trophic (energy

levels)

Homeostasis has to be maintained.