Lesson Overview
Energy, Producers, and Consumers
Lesson Overview
Energy Flow
(3.2 and 3.3)
Lesson Overview
Energy, Producers, and Consumers
Number 1
Why do living things need energy?
Growth, reproduction, and their own metabolic processes
No energy = No life functions
Lesson Overview
Energy, Producers, and Consumers
Number 2
Can organisms create their own energy?
No – Organisms only use energy from other sources
Organisms can convert energy from one source into a
usable form of energy
Lesson Overview
Energy, Producers, and Consumers
Number 3
What is an autotroph?
An organism that uses solar or chemical energy to produce
“food” by assembling inorganic compounds into complex
organic compounds
Autotrophs store energy in forms that make it available to
other organisms that eat them
Autotrophs are the first producers of energy-rich compounds
that are later used by other organisms (autotrophs are
also called primary producers)
Examples include algae, certain bacteria, and plants
Lesson Overview
Energy, Producers, and Consumers
Number 4
What is photosynthesis?
Light energy is captured and used to power chemical
reactions that convert carbon dioxide and water into
oxygen and energy-rich carbohydrates such as sugars
and starches
Lesson Overview
Number 5
Photosynthesis
Algae
Cyanobacteria
Green plants
Produces oxygen
Requires light
Energy, Producers, and Consumers
Lesson Overview
Energy, Producers, and Consumers
Number 5
Chemosynthesis
Sulfur bacteria
Uses hydrogen sulfide
Lesson Overview
Energy, Producers, and Consumers
Number 5
Both (photosynthesis and chemosynthesis)
Primary producers
Produces carbohydrates
Lesson Overview
Energy, Producers, and Consumers
Number 6
What is a heterotroph?
An organism that must acquire energy from other organisms –
by ingesting them in one way or another
Heterotrophs rely on other organisms for energy and nutrients
Heterotrophs are also called consumers because they must
consume for energy and nutrients
Lesson Overview
Energy, Producers, and Consumers
Number 7
Herbivore
Obtain energy and nutrients by eating plant leaves, roots,
seeds, or fruits
Examples of herbivores include the military macaw, cows,
caterpillars, and deer
Lesson Overview
Energy, Producers, and Consumers
Number 7
Carnivore
Kill and eat other animals
Examples include snakes, cats, and this giant river otter.
Catching and killing prey can be difficult and requires energy,
but meat is rich in nutrients and energy and is easy to
digest
Lesson Overview
Energy, Producers, and Consumers
Number 7
Omnivore
Animals whose diets naturally include a variety of different
foods that usually include both plants and animals
Humans, bears, and pigs are omnivores
Lesson Overview
Energy, Producers, and Consumers
Number 7
Scavenger
Animals that consume the carcasses of other animals that
have been killed by predators or have died of other causes
An example is the king vulture
Lesson Overview
Energy, Producers, and Consumers
Number 7
Decomposer
Chemically break down organic matter
The decay caused by decomposers is part of the
process that produces detritus—small pieces of dead
and decaying plant and animal remains
Examples include bacteria and fungi
Lesson Overview
Energy, Producers, and Consumers
Number 7
Detritivore
Feed on detritus particles, often chewing or grinding them
into smaller pieces
Detritivores commonly digest decomposers that live
on, and in, detritus particles
An example is the earthworm
Lesson Overview
Energy, Producers, and Consumers
Number 8
Compare and contrast food chains and food webs
Both show the transfer of energy
Food chains show one sequence of energy transfers and a
food web shows all of the feeding interactions in an
ecosystem
Arrows point in the direction of energy transfer
Lesson Overview
Energy, Producers, and Consumers
Number 9
Four food chains
from this food web
Lesson Overview
Energy, Producers, and Consumers
Number 10
How are decomposers related to a recycling center?
Decomposers break down dead and decaying matter and
release nutrients that can be reused by primary producers
Decomposers take apart matter so that producers can
rebuild the matter
Lesson Overview
Energy, Producers, and Consumers
Number 11
What is a trophic level?
Each step in a food chain or food web
The first trophic level is always the primary producers
Lesson Overview
Energy, Producers, and Consumers
Number 12
The three ecological pyramids
PYRAMID OF ENERGY = Shows the relative amount of
energy available at each trophic level of a food chain or
food web
PYRAMID OF BIOMASS = Illustrates the relative amount of
living organic matter available at each trophic level in an
ecosystem
PYRAMID OF NUMBERS = Shows the relative number of
individual organisms at each trophic level in an
ecosystem
Lesson Overview
Energy, Producers, and Consumers
Number 13
Can any of the pyramids be turned upside down?
YES – The pyramid of numbers may be turned upside down
Thousands of insects may graze on a single tree
Countless mosquitoes can feed off a few deer
The other pyramids will not be turned upside down
Lesson Overview
Number 14
Energy Pyramid
Sunlight
Energy, Producers, and Consumers
Lesson Overview
Energy, Producers, and Consumers
Number 14
Energy Pyramid
Sunlight
Primary Producers (100%)
Lesson Overview
Energy, Producers, and Consumers
Number 14
Energy Pyramid
First-level consumers (10%)
Sunlight
Primary Producers (100%)
Lesson Overview
Energy, Producers, and Consumers
Number 14
Energy Pyramid
Second-level consumers (1%)
First-level consumers (10%)
Sunlight
Primary Producers (100%)
Lesson Overview
Energy, Producers, and Consumers
Number 14
Energy Pyramid
Third-level consumers (0.1%)
Second-level consumers (1%)
First-level consumers (10%)
Sunlight
Primary Producers (100%)