Ecology Review
Living things do not live in vacuums, their daily
lives are based on _______________ with
both living and nonliving things.
What is an ecosystem?
Groups of organisms and their ____________
________________________
What is the Biosphere?
All _____________________are connected in a
biosphere
34-1
Ecology Terms
Organism living thing
Population groups of ____________
Communitygroup of _____________
Ecosystemgroup of _____________
Biome Group of ________________
Biosphere Group of _____________
34-2
There are two main components of an
ecosystem:
________ (living)&
________(nonliving)
Populations of
organisms.
Inorganic nutrients,
physical features,
water, temperature,
and wind.
34-3
Biotic Components: A Closer Look
______________ are producers that
produce food for themselves and for
consumers.
How do autotrophs make food?
_____________ and chemosynthesis
____________ are consumers that
take in premade food.
34-4
Biotic components
34-5
Consumers Vocabulary:
Herbivores – animals that eat __________
Carnivores – animals that eat ___________
Omnivores – animals that eat ________
and ______________
Decomposers - bacteria and fungi, that
________________dead organic waste.
Detritus - partially ______________organic
matter in the soil and water; beetles,
earthworms, and termites are detritus
_____________.
34-6
Consumers
34-7
Consumer Levels
Primary consumer – an organism that
gets its energy from ______ (producers)
Secondary consumer – an organism that
gets its energy from ________________
Tertiary consumer – carnivores that eat
other carnivores; a _________consumer,
usually the top predator in the food chain
34-8
Biotic Interactions
Organisms occupy a specific role, or ________, in an environment
•Competition  fig_____________________or species
for food/habitat/mate
•Predation  action where a hunter _________________
•Symbiosis  situation where 2 organisms interact with
each other and ________________from this interaction
34-9
Energy Flow
What is energy flow?
• The _________________through the
organisms in an ecosystem
What direction does energy flow through an
ecosystem?
• Sun  Producers  Various levels of
__________________
34-10
• As energy flows from autotrophs
(producers) to heterotrophs (consumers)
much of the energy is lost before the
consumer can use it.
• In what forms is energy lost?
___________________
• Initial energy from an ecosystem comes
from a consistent supply of solar energy
**Remember energy in an ecosystem may
be transferred or converted but will not be
__________________________**
34-11
Energy balances
34-12
Nature of an ecosystem
34-13
Food chains vs. food webs
What is a food chain?
A diagram that links organisms together by who eats
whom
• Starts with ________________________________.
• Most food chains have no more than ____________
• Arrows show the direction energy is flowing
• EXAMPLE: tree  giraffe  lion
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Food chain
34-15
Most consumers feed on and are eaten by more
than one other consumer
What is a food web?
• A combination of several food chains showing all
of the ____________________________
•What is a trophic level?
All of the organisms that feed at a
_______________________of the food chain/web
34-16
Grazing food web –
The upper portion of a food web based on a
______________________________
Detrital food web –
The lower portion of a food web based on
__________________
34-17
Forest food webs
34-18
Ecological Pyramids
Why are food chains so short?
Only about __________of energy is useable from
one trophic level to the next
• The number organisms drastically decreases as
you go up in level of a food chain
What is an ecological pyramid?
A series of _________ representing the biomass of
particular organisms on a particular trophic level
What is biomass?
The amount of ___________________in the
population of an organism
34-19
Ecological pyramid
34-20
Biochemical cycles
What are biochemical cycles?
• The path by which important
nutrients/molecules travel through an
ecosystem.
3 Important Cycles:
• Water Cycle
• Carbon Cycle
• Nitrogen Cycle
34-21
The Water Cycle
Water movement:
Land  Atmosphere:
• _________________
• _________________from rivers, lakes and oceans
• ______________________ from plants
Atmosphere  Land
• _____________________
• ________________ over land and bodies of water
• Runoff forms bodies of water (lakes, rivers, oceans)
• Ground water seepage into aquifers
34-22
The water cycle
34-23
The Carbon Cycle
Carbon Movement:
Land/Water  Atmosphere
• _________________
• _________________
Atmosphere Land/Water
• ___________________
• ________________
** Carbon is stored as _fossil fuels__ from decaying
organisms.**
34-24
The carbon cycle
34-25
The Nitrogen Cycle
Nitrogen Movement:
•Nitrogen Fixation  ___________ found in
legume roots converts ______________________
• Decomposers break down waste and organic
remains into __________________
•Nitrification  bacteria convert ____________into
Nitrite (NO2) and Nitrate (NO3) to be used by plants
•Denitrification  Bacteria converts ammonia back
into _________________________
34-26
The nitrogen cycle
34-27
The Phosphorus Cycle
The phosphorus cycle is a sedimentary cycle.
Only __________________are made
available to plants by the weathering of
sedimentary rocks; phosphorus is a limiting
inorganic nutrient.
The biotic community recycles phosphorus
back to the ______________, temporarily
incorporating it into ATP, nucleotides, teeth,
bone and shells, and then returning it to the
ecosystem via __________________.
34-28
The phosphorus cycle
34-29
Changes to Ecosystems
Air Pollution  Burning of _________releases
CO2, SO2, and NO2,NO3 into atmosphere.
Results in climate change, acid rain,
damage to ozone layer
34-30
Habitat Destruction
• Over past 50 years, __________of tropical
forests have been cleared for timber or
farmland (deforestation)
• Loss of habitat often means ___________for
organisms within that habitat
34-31
Invasive Species
Introduction of species to new habitats,
usually by humans
34-32