BIOLOGY: Food Webs & Energy Pyramids

Biosphere

the portion of Earth
that supports living things.
If Earth were an apple, it'd be
thinner than an apple peel.

Populations

A group of organisms, all of
the same species, which interbreed and live
in the same area at the same time.

Biological communities

Made up of interacting populations in a
certain area at a certain time.

Ecosystems

Made up of interacting
populations in a biological community
AND the community's abiotic factors.

Ecology

The study of relationships on
several levels of biological organization.
(Complexity...)

Abiotic Factors

nonliving parts
of an organism's environment

Abiotic Factor examples

Air currents
Temperature
Moisture
Light
Soil

biotic factors

All living organisms that
inhabit an environment.

Biotic Factor examples

drought

Depend

All organisms _______________ on others directly
or indirectly for food, shelter,
reproduction, or protection.

Levels of the Living world

1) organisms
2) populations
3) communities
4) Ecosystems

compete

Members of the same population may
_______________ for the same resources.

adapt

Some species _________ to reduce competition

Give an example of how adult frogs and moths adapt.

They have different food requirements than tadpoles and caterpillars

Ecosystem Examples

Meadows
Volcano site
Rotting log
Pond
Ocean
Human skin
Refrigerator

Autotrophs (producers)

make their own food.

Heterotrophs (consumer)

cannot make their own food.

1st order -

obtain food from plants (herbivores)

2nd order

- feed on 1st order heterotrophs

3rd order

- feed on 2nd order heterotrophs

Decomposers (Heterotrophs)-

break down living matter and help
release nutrients at every level in a food chain. (Protozoans,
bacteria, fungi)

food chain

A simple
model that shows how
matter and energy
move through an
ecosystem.

food web

Shows all the possible feeding relationships
at each trophic level in a community.
-More realistic
-Network of interconnected
food chains
-Models the distribution of matter and energy within an
ecosystem (energy flow)

Ecological Pyramids

Another model to show the flow of
energy through an ecosystem.

energy Pyramids

-Shows the amount of available energy at
each trophic (feeding) level.
-Available energy decreases with each
succeeding trophic level
-Total energy transferred from one
trophic level to the next is 10%.

number pyramids

Shows that population sizes decrease
at each higher trophic level.

Biomass

The total weight of living
matter at each trophic level.

gross primary productivity

the amount of chemical energy as biomass
(food) that primary producers create in a
given length of time. (The rate of energy
captured by plants from the sun.)

Net Primary Productivity (NPP)

Lower;
adjusted for the energy that is lost to
respiration. (It's what can actually be used.)