ENERGY FLOW
PHOTOSYNTHESIS
How energy enters the ecosystem
Carbon dioxide + water
glucose + oxygen + water
Explain using your own words the process of photosythsis
CELLULAR RESPIRATION
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Process that most living organisms (including animals, plants,
fungi and microorganisms) use to obtain energy from glucose
sugar and oxygen.
Energy is released
The wastes formed are carbon dioxide and water.
Glucose + oxygen -> carbon dioxide + water + energy
FOOD CHAIN & FOOD WEB
List the prey of the snake
What do you think would
happen if if Hawks and Owls
were removed from the food
web?
FOOD CHAIN
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Shows different organisms that live in a habitat
Arrows show the direction of the flow of energy
Always starts with a producer (plant produces its own food
source via photosynthesis also called autotrophs)
Ends with consumers (an organism that eats plants & other
organisms)
FOOD WEB
All the food chains from a community
linked together
Various levels in a food web called
trophic levels
Plants capture the Sun’s energy &
this energy is passed onto
herbivores and carnivores.
Decomposers complete the flow of
energy
ECOLOGICAL PYRAMIDS
Ecological Pyramid – another way of representing a food
chain
Pyramid of Numbers – shows the numbers of organisms
at each level at any one time. There are lots of producers
and progressively fewer consumers
PYRAMIDS
Pyramid of Biomass – refers to the total amount of dry
mass accumulated by living organisms over an area at
each level at any one time
PYRAMIDS
Pyramid of Energy – shows the transfer of energy through the
ecosystem. About 1% of the Sun’s energy that reaches the Earth
is used by green plants, which make active use of it.
Only a small part of this energy remains stored in the plant. This
stored energy is passed on as food to the next level
At each level, most of the energy is used by the organisms at that
level & lost as heat, leaving little to be passed on
Each level has less energy available to it that the previous level
Therefore, there are fewer organisms at the top of the pyramid
because there is less energy available for life