Chapter 3 – The Biosphere
interact
All organisms __________with
the environment  to
understand these_______________,
interactions we study ecology
_________= the scientific study of interactions among organisms
Ecology
and between organisms and their environment (surroundings)
organization
Ecology is all about ________________
this leads to a better
understanding of the interactions that take place
_____________ = the combined
Biosphere
portions of the planet in which
all life exists, including land,
water, air, or atmosphere
There are 5 levels of organization within the biosphere; a
species, populations, communities, ecosystems, and biomes
1. Species
Species = a group of organisms so similar to one another that
they can breed and produce offspring
an individual most
This levels of organization looks at just _________________
of the time
2. Population
Population = a group of individuals that belong to the
same species and live in the same area at the same time
3. Communities
Communities = assemblages of different populations
that live together in the same area at the same time
4. Ecosystem
Ecosystem = collection of all the organisms that live in a certain
area, together with the nonliving (physical) environment
5. Biome
Biome = a group of ecosystems that have the
same climate and similar dominant communities
Ecologists use a wide range of tools and techniques to study
the living world
The 3 basic approaches ecologist use are _____________,
observing
__________________, and ____________
experimenting
modeling
In order for organisms to interact, they need energy!
Sunlight is the main source of energy for life on Earth
____________
Some types of organisms rely on energy stored in ___________
inorganic
__________________________
chemical compounds
Autotrophs = organisms that can capture energy from the
________________
sun or chemicals to produce food
producers
They are also called ______________
Includes plants, some algae, since they make their own food
and certain bacteria
start
Producers help _______the
flow of
energy through the biosphere
photosynthesis to use light
Most autotrophs we think of use ___________________
energy to power chemical reactions that produce carbs
Photosynthesis adds
___________
oxygen to the
atmosphere and removes
CO
_____2
Land plants, as well as algae
that remain in the sunlit
portion of aquatic
environments use
photosynthesis
chemosynthesis
Some autotrophs use ____________________
(chemical reactions) to produce carbs
Many ___________
bacteria use
chemosynthesis
Heterotrophs = organisms that rely on other organisms
_________________
for energy and food supply
They are also called consumers
There are several different types of heterotrophs
1. ______________
Herbivores – only eat plants
(cows, caterpillars, deer)
2. Carnivores
_____________ – only eat
animals (lions, snakes, owls)
Omnivores – eat both plants and
3. ______________
animals (humans, bears, crows)
Detritivores
4. ________________(scavengers)
– feed on animal and
plant remains and other dead matter (vultures)
5. _________________–
Decomposers break down
organic matter (bacteria and fungi)
Energy flows through ecosystems in one direction;
sun/inorganic compounds  autotrophs  heterotrophs
_____________
Food
chain = a series of steps in which organisms
transfer energy by eating or being eaten
In a food chain, the arrows point in
the
direction in which energy is
_______________
transferred
The amount of energy remaining is _______________
only a portion
of what was available at the first transfer
Ex. Grass  antelope  coyote
____________
Food
web = shows the complex network of
interactions within an ecosystem
Food webs link the food chains
in an ecosystem together
Food webs can be
________________
very complex because 1
producer can be food for
several consumers and 1
consumer can feed on several
types of producers as well as
other consumers
Trophic
level = each step in a food chain or food web
________________
Producers are the 1st trophic level
_____________
Consumers make up the 2nd, 3rd,
______________
or higher trophic levels
Each consumer depends on the
trophic level below for energy
pyramids
Ecologist have come up with ecological
______________________
to model energy or matter in an ecosystem
_______________________
Ecological
pyramids = a diagram that shows the
relative amounts of energy or matter within each
trophic level in a food chain or web
There are 3 types of pyramids;
energy, biomass, numbers
1. Energy pyramid – shows the amount
of energy available at each trophic level
10% of the energy gets passed from one trophic
Only about _______
level to the next
The transfer amount is small because organisms use much of
respiration
the energy they obtain for basic processes like ______________,
_____________, and ________________
movement
reproduction
The more trophic levels, the ______
less energy reaches the top
2. Biomass pyramid – shows the total amount of
living mass (biomass) in a given trophic level
Biomass is usually expressed in grams per unit area
It represents the amount of potential ______
food available
for each trophic level
3. Pyramid of numbers – shows the
number of individuals at each trophic level
Sometimes the shape of the numbers and biomass pyramid are
the same because ______________________
lots of individuals produce food for a
_________________
lesser number of consumers
Sometimes a numbers pyramid can be upside down when ____
one
producer can be food for ____________________
many consumers (Ex. one trees
_____________
feeds many insects)
Section 3-3:
Cycles of Matter
Organisms need more than just energy to
survive  they need nutrients too!
Energy only flows one way, but
matter is _________________________
recycled within and
between ecosystems
___________
Biogeochemical
cycles = connect
__________________________
biological geological, and
chemical aspects of the biosphere
to help recycle matter
Matter is never used up, it is transformed
 that is why it can be recycled
The water cycle is very important because
all living things require water to live!
evaporates (liquid to gas) from lakes and oceans
Water _______________
and becomes ________________
water vapor
Plants release water vapor through transpiration
breathe (also when
Animals release water vapor when they __________
they perspire/urinate)
As water cools high in the atmosphere, it condenses on dust
in the air to form clouds
Eventually the water vapor _____________
condenses enough to fall as
_________________
precipitation
______________
Nutrients = all chemical substances
that an organism needs to sustain life
Every living organism needs nutrients to build tissues and
carry out essential life functions
carbon ____________,
nitrogen and _______________
The_________,
phosphorus cycles are
important nutrient cycles (oxygen is involved in each)
The carbon cycle! – we have already learned that carbon is a
very important element
Carbon takes many forms and is
a key ingredient of _______________
living tissue
4 main processes move carbon through its cycle
Biological processes like
1. _____________
photosynthesis, respiration, decomposition
Geochemical processes like erosion and volcanic activity
2. _________________
3. ____________________________
Mixed biogeochemical processes like burial
and decomposition of dead organisms
4. _____________________
Human activities like mining, cutting/burning
forests, and burning fuels
The nitrogen cycle! – nitrogen is essential for
amino acids and protein building
There are many different naturally occurring forms of nitrogen
78% nitrogen, most plants can’t use it
– even though the air is _____
Certain bacteria
_________ on plant roots can help convert the nitrogen
in the air to usable nitrogen in ammonia (_____________________)
nitrogen fixation
Animals eat plants and use the nitrogen proteins for various
form muscles
uses (__________________)
When animals _________,
urinate nitrogen is released back into the soil
dies
for plant use (the same thing happens when an animal ______)
Some soil bacteria convert nitrates into nitrogen gas through
denitrification
The phosphorus cycle! – phosphorus is
important in the formation of DNA and RNA
Phosphorus cycles in 2 ways
______________ – when animals die, phosphorus is returned to
Short-term
the soil to be used again
______________
Long-term – phosphates get incorporated into rock and
other insoluble compounds – millions of years later that rock
becomes exposed and erodes, releasing the phosphorus back
into the local system
Since nutrients are so important to ecosystems, they can
sometimes be limiting
_________________________
Primary productivity of an
ecosystem = the rate at which organic
matter is created by producers
Sometimes an ecosystem is
limited by a single nutrient
Primary productivity is limited by (_____________________)
limiting nutrient
available nutrients
Oceans are considered __________________
nutrient-poor compared to land
An _______________
algal bloom can occur
when a large amount of the
limiting nutrient is introduced
to an aquatic ecosystem
These blooms can disrupt the
equilibrium of a system
________________
Grand Lake on July 1st, 2011