Transcript Feeding Relationships

Feeding Relationships
Give Me Energy or Give Me Death!!!
(not quite Patrick Henry)
• All organisms need energy to live.
• 3 Types of Organisms
– Producers
– Consumers
– Decomposers
Producers
• Organisms that make their own food using energy from
the sun (photosynthesis) or by other means.
• Ex. Plants, algae, some bacteria
Consumers
• Any organism that gets its food by eating other
organisms.
• Types of Consumers
– Herbivores
• Plant eaters
• Ex. Rabbit
– Carnivores
•
•
•
•
Meat-eaters
Eat herbivores or other carnivores
Ex. Shark, wolves
Scavengers: eat dead things
Consumers
• Types of Consumers
– Omnivores
• Eat both producers
and other consumers
• Ex. Raccoon, bears,
most people
Decomposers
• Organisms that feed on the remains or wastes of
other organisms.
• Recycle the nutrients back into the soil
• Often left out of food chain
• Ex. Bacteria and fungi
Food Chain
• Traces the path of energy as it moves from one
organism to the next in an ecosystem.
• Shows only 1 energy path in an ecosystem.
Notice how all energy begins with the SUN
Producer=Photosynthesis
Consumers
Food Chain
Tertiary Consumer
Producer
Secondary Consumer
Primary Consumer
Decomposers
Food Chain Terminology
• Producer
– Photosynthetic organism that gets energy from sun.
• Primary Consumer (1°)
– First to feed.
– Herbivore
– Most energy gets used, some gets lost as heat, and
some gets passed onto the secondary consumer.
• Secondary Consumer (2°)
– Eats the primary consumer (herbivore)
– Carnivore, omnivore, or scavenger
Food Chain
• Tertiary Consumer (3°)
– Eats the 2° consumer
• Decomposer
– Eats the remains of
the consumers.
– Obtains the little
energy that is left from
the consumers.
Food Web
• A system of several overlapping food chains.
• Provides a more complete picture of the flow of
energy in an ecosystem.
Third-level
Consumers
Bobcat
Hawk
Second-level
Consumers
Weasel
First-level
Consumers
Desert
Cottontail
Woodrat
Producers
Prickly Pear
Cactus
Mesquite
Energy Flow
• As energy is passed from organism to organism it
is used to carry out cell processes and some is
lost to the environment as heat.
• 10% Rule
– Only about 10% of the energy present at one feeding
level is passed to the next feeding level.
• Energy Pyramid
– Another way of showing the transfer of energy from one
level to the next.
Energy Pyramids Show
• That the amount of
available energy
decreases down the food
chain
• It takes a large number of
producers to support a
small number of primary
consumers
• It takes a large number of
primary consumers to
support a small number of
secondary consumers
10% Rule & Energy Loss
Summary Questions
• Name the three energy roles of organisms in an
ecosystem. How does each type of organism
obtain energy?
• How does the amount of available energy change
from one level of an energy pyramid to the next
level up?
• Name and define the four types of consumers.
• What is the source of energy for most
ecosystems?
• Why are food webs a more realistic way of
portraying ecosystems than food webs?