Warm-Up
Answer the following question in a
complete sentence.
Name/Nombre
Date/Fecha
Period ____
Where does all energy in an ecosystem
ultimately come from?
Suggested sentence stem:
All energy in an ecosystem ultimately comes from…
Question!
You eat about 6 pounds of food
every day. Your poop and pee
total to about 4 pounds.
Do you actually gain 2 pounds
every day? What happens to
those 2 pounds?
UNIT
Energy Flow: Food Pyramids
2
Energy Flow: Food Pyramids
Energy Flow: Food Pyramids
• A food pyramid shows matter and energy at each trophic level.
UNIT
2
UNIT
Energy Flow: Food Pyramids
2
• A food pyramid shows matter and energy at each trophic level.
• A biomass pyramid shows
how much matter is at each
level (numbers lower as you go
tertiary
consumers
up levels).
75 g/m2
150g/m2
secondary
consumers
primary
consumers
producers
producers
675g/m2
2000g/m2
Energy Flow: Food Pyramids
• A food pyramid shows matter and energy at each trophic level.
• A biomass pyramid shows
how much matter is at each
level (numbers lower as you go
up levels).
• A numbers pyramid shows
how many of each species
is at each level (doesn’t
always go up).
UNIT
2
UNIT
Energy Flow: Food Pyramids
2
• A food pyramid shows matter and energy at each trophic level.
• A biomass pyramid shows
how much matter is at each
level (numbers lower as you go
up levels).
• A numbers pyramid shows
how many of each species
is at each level (doesn’t
always go up).
• An energy pyramid shows
the amount of energy at
each level.
0.2 Joules
2 Joules
20 Joules
200 Joules
UNIT
Energy Flow: Food Pyramids
2
• A food pyramid shows matter and energy at each trophic level.
• An energy pyramid shows
the amount of energy at
each level.
• The 10% Rule says as you
go up a trophic level, the
energy divides by 10.
What happens to the other 90%?
0.2 Joules
2 Joules
20 Joules
It gets lost as heat.
(that’s what happens to the other 2 pounds
every day!)
200 Joules
Turn-and-Talk
Discuss the following question with your partner. I will call on
three people to give me their thoughts.
Discuss and explain why food chains usually do
not exceed more than four links. In other
words, why do food chains not usually have
higher than tertiary consumers?
Food chains do not usually exceed more than
four links because…
UNIT
2
Make a 3D Pyramid
4th TL
75 g/m2
3°
Con
s 3rd TL
2°Consumers
2nd TL
1° Consumers
1st Trophic Level
150 g/m2
___ J
____ J
Producers
____ J
1334 J
675 g/m2
2000 g/m2
Closure
Answer the following question in a
complete sentence:
Name/Nombre
Date/Fecha
Period ____
Explain the loss of energy from one trophic level to the
next. What happens to the lost energy?
Suggested sentence stem:
The lost energy…