CHAPTER 2
PRINCIPLES OF ECOLOGY
ORGANISMS AND THEIR
RELATIONSHIPS
• Main Idea for Ch. 2.1:
–Biotic and abiotic factors interact in
complex ways in communities and
ecosystems.
• Discussion:
–Who or what do you
depend on?
• ECOLOGY
–_________________ is the
scientific area in which the
relationships among living
organisms & the _____________
the organisms have with their
environments are ___________.
• ECOLOGY
• Scientists who study ecology are called
__________________.
–Ecologists perform __________ in the environment
where organisms live to find out why they die or live,
grow in number or decrease, live in water or near the
water, etc.
–Ecologists use ________________ so they can test in
a lab things that are happening in the environment.
» Models help scientists _______________________ the
variables and study them _______ at a time.
» EX: more or less water, more or less light, temperature
changes, etc.
» Helps scientists completely understand the _________
taking place in the environment.
• Discussion:
• Which task would be completed by an ecologist?
– Survey and classify mollusk fossils
– Inoculate cattle against infection
– Test the effect of cyanide on algae
– Explore the medicinal uses of nectar
• What are some locations where you might find
ecologists collecting data, and what tools might
they use in these locations?
• What types of organisms have you ever observed or
collected that live near your home?
• What are some interesting characteristics of these
organisms?
• THE BIOSPHERE
– _______________ is the portion of Earth that supports life.
• The prefix “______________” means
__________________.
• EX:
Rainforest
Desert
Marine Life
• Ecologists study these _______________, their
_________________, & the factors in their environments.
– These factors are divided into 2 large groups.
» Living factors – _____________________
» Nonliving factor - ____________________
• BIOTIC FACTORS
• Anything ____________________ in an organism’s
environment are called ________________ factors.
– The interactions are necessary for the health of all
species in that _______________ location.
– What are some of the biotic factors in this picture and
how do they relate to one another.
• ABIOTIC FACTORS
– ___________________ factors in an organism’s
environment are called
_____________________factors.
– Abiotic factors include:
• Temperature
• ______________________
• ______________________
• ______________________
• Soil types
• Rainfall
• Nutrients
• ABIOTIC FACTORS
– Abiotic factors needed for organisms to survive
– Organisms develop _____________________to live with
the abiotic factors.
– If the abiotic factors ___________________ organisms
need to change or they will ________________.
– Argument: Oxygen is the only abiotic factor that allows
you to survive in this classroom. So, as long as there is
enough oxygen, all of you will survive.
• LEVELS OF ORGANIZATION
• Levels of organization increase in _______________
as the numbers and interactions between
organisms increase.
• Levels of organization are:
– _________________________________
– _________________________________
– Biological _________________________
– _________________________________
– _________________________________
– _________________________________
• Look up & write in your own words a definition for
the following levels of organization.
• ORGANISM - _____________________________
__________________________________________
__________________________________________
__________________________________________
• POPULATION - ____________________________
__________________________________________
__________________________________________
__________________________________________
• Look up & write in your own words a definition for
the following levels of organization.
• BIOLOGICAL COMMUNITY - __________________
__________________________________________
__________________________________________
__________________________________________
• ECOSYSTEM - _____________________________
__________________________________________
__________________________________________
__________________________________________
• Look up & write in your own words a definition for
the following levels of organization.
• BIOME - _________________________________
__________________________________________
__________________________________________
__________________________________________
• BIOSPHERE - ______________________________
__________________________________________
__________________________________________
__________________________________________
• ECOSYSTEM INTERACTIONS
• ___________________ of the different populations
____________________ if they use the resources in
__________________________ ways.
– EX: birds use different areas of the tree to build nests.
• __________________ is an area where an organism
______________________.
– EX: deer covering 5 sq. miles to find food.
• __________________ is the __________ or position
that an organism has in its _______________ (habitat).
– EX: food, shelter, and reproduction
• Discussion:
– What is an example of a habitat and an individual’s niche in
that habitat?
• COMMUNITY INTERACTIONS
• Interactions in the community include
__________________ for basic needs like
food, shelter, mates, and how organisms
depend on each other for
__________________________.
• COMPETITION
–___________________ occurs when
__________ than 1 organism uses the
__________________ at the
_________________ __________________.
• The organism that out
________________ the other one is the
one that _________________.
• PREDATION
–_________________ is when one
organism hunts and _______ another
organism for food.
• _____________ is the organism that
is _________________ the hunting.
• ___________ is the organism that is
caught and ___________.
• EX: mallard duck eating water bug.
• SYMBIOTIC RELATIONSHIPS
• _______________ is the close relationship that exists when 2 or
more species _______________________________________.
• There are 3 different types of symbiosis:
– ____________________________________
• Both organisms receive a _________________________
– EX: flowers and bees
– ________________________________________________
• One organism receives a ________________ & the other
one is __________________ hurt or harmed.
– EX: clownfish and sea anemones
– ____________________________________
• One organism receives the ____________________ & the
other one is hurt or _____________________.
– EX: Fleas, ticks, tapeworms, etc.
Section 2.2
• FLOW OF ENERGY IN AN ECOSYSTEM
• ____________________ capture energy,
making it available for all members of a
______________ ______________.
• The sun is the original source of
____________!
• ENERGY IN AN ECOSYSTEM
• Organisms differ in how they obtain energy. They are
either __________________ or ________________.
• AUTOTROPHS
– Autotrophs are organisms that collect energy from
___________________ or inorganic substances to
produce _______________________________.
• EX: plants, bacteria
– Autotrophs ________________________ all food chains
in an ecosystem
– Autotrophs are also called _______________________
• Discussion: What is the process by which autotrophs
convert light energy into chemical energy?
• HETEROTROPHS
–_______________________
is an organism that gets
energy by consuming other
organisms.
–Heterotrophs are also called
______________________.
• Different types of consumers:
– _____________________ – only eats plants, EX: cow
– _____________________ – only eat meat, EX: lions
– ___________________ – eat both meat & plants, EX:
bears
– ____________________ - eat fragments of dead matter
in an ecosystem and return nutrients back to the soil, air,
and water where the nutrient can be recycled by other
organisms. EX: worms
– ___________________ (similar to detritivores) – break
down dead organisms by releasing digestive enzymes.
EX: fungi (mushrooms)
• MODELS OF ENERGY FLOW
–Ecologists use food chains & food
webs to model the _____________
flow through an ecosystem.
–A ___________________________ is a
step in a food chain or web.
–Autotrophs/plants make up the
______ trophic level in all ecosystems.
–_____________________ make up all
__________________________ levels.
• FOOD CHAINS
• _______________ is a simple model that
show how energy flows through an
ecosystem.
• The _____ show what direction
the energy flows, which usually
starts with the autotrophs and
moves to the heterotrophs.
• FOOD CHAINS
• In a food chain the energy _________
flows in one direction, _______ the
tropic levels.
• Some of the energy is ________
transferred from one trophic level
to the next because it is _________ by
the organism for ___________________
& _________________.
• FOOD WEBS
• A food ________ is a model representing the many
______________________ food _______________
and pathways in which energy flows through a
group of organisms.
http://www.goldridge08.com/foodchain.htm
• ECOLOGICAL PYRAMIDS
– An ecological pyramid is a diagram that shows
the relative amounts of energy biomass or
numbers or organisms at each trophic level in an
ecosystem.
– _________________ pyramid only ______ of the
energy is transferred to the next level.
• The organism uses ______ of the energy for
____________________ processes or released
as __________.
• ECOLOGICAL PYRAMIDS
–_________________ pyramid shows
the amount of total ________ of living
matter at each trophic
level
–Pyramid of _____________ shows the
number of organisms at ____________
trophic level
SECTION 2.3
• CYCLING OF MATTER
–Essential _____________________ are
_________________________ through
biogeochemical processes.
• Discussion:
–What would happen if matter was
bound in living matter and never
recycled?
• CYCLES IN THE BIOSPHERE
• Energy is transformed into __________________
forms to support life of an ecosystem.
– Constant supply needed so matter needs to be
_____________________________.
• _______________ is anything that takes up
space and has mass.
• __________________ is a chemical substance
that an organism must obtain from its
environment to sustain _______________ and to
undergo life processes.
• CYCLES IN THE BIOSPHERE
• _____________________________________
cycle is the exchange of matter through the
biosphere.
–Bio means life, ________ means
_____________, & chemical
–Producers (plants) use air, soil and water to
convert them into usable nutrients.
Consumers eat the plants & the nutrients
are passed to them. Decomposers will
return the nutrients to be recycled.
• WATER CYCLE
• Water is constantly _____________________ from
water & going up into the atmosphere in the form
of __________________________________.
– ____________ of all evaporation occurs over the
_______________, lakes, and rivers.
– ______ evaporates from plants through a process
called __________________________________.
• Water vapor creates ___________________ & then
_________________________________________.
• Ends up on the surface & is soaked up by plants or
remains underground. Can fall in lakes or streams &
return to ocean
• THE WATER CYCLE - CONTINUED
• Organisms _________________ live without water.
• ____ of all water on Earth is __________. ______ of
all fresh water is either frozen in _______________
or _______________________________.
• THE CARBON AND OXYGEN CYCLES
• All living things are composed of molecules
that contain ___________, such as protein,
carbohydrates and fats.
• Carbon and oxygen make up molecules
essential for life, including _____________
and simple __________.
• Carbon can be ___________ for long periods
of time as ___________ ____________ &
released when burned, adding carbon dioxide
to the atmosphere.
• THE CARBON AND OXYGEN CYCLES
• In ____________________________, plants
and algae, will convert carbon dioxide + water
into carbohydrates + oxygen for the
atmosphere.
–These carbohydrates are used as a source of
_____________ for all organisms in the
food web.
–Carbon dioxide is _____________________
back into the atmosphere through cellular
respiration. (You do cellular respiration)
• Discussion:
– Based on your understanding of the carbon cycle,
predict what might happen if large areas of tropical rain
forest continue to be cleared.
– How do you interact in the carbon cycle?
• THE NITROGEN CYCLE
• Nitrogen is an ____________________________.
• Largest amount found in ____________________ as a gas.
– Can’t be used by plants and animals in this form
• __________________________________occurs when
__________________ convert the nitrogen gas to
______________________/nitrites/ammonia.
– Enters food web when plants ______________ nitrogen
compounds from the ________ & convert them into
protein.
– Nitrogen is often a ______________________________
for the growth of producers.
– _______________________________ will return
nitrogen in protein back into ammonia.
• THE NITROGEN CYCLE
• Reverse process is called
denitrification
• ___________________________
occurs when bacteria convert the
nitrogen compounds (nitrates,
nitrites & ammonia) back into
________________ gas returning it to
the atmosphere.
• NITROGREN CYCLE
• THE PHOSPHORUS CYCLE
• Phosphorus essential for _________________________ &
development of organisms.
• Short term cycle:
– Soil →producers →consumers
– Decomposers return phosphorus to soil
• Long term cycle:
– ____________ in sedimentary ______
– _____________ through weathering
or ____________________________
• Phosphorus is a __________________
__________________________.