Transcript Ch 3 Biosphere Notes

Chapter 3: The Biosphere
What is ecology?
Ecology
• Ecology – the study of interactions among
organisms and between organisms and their
environment
• Interdependence – dependence of every
form of life on other living things and
natural resources (air, water, land) in its
environment
Levels of Organization
• Biosphere – largest, portions of planet
where life exists (land, H2O, air)
– 8 km above to 11 km below
• Biome – group of ecosystems with same
climate (temp. and rainfall)
• Ecosystem – collection of all organisms in a
particular place together with the abiotic
(physical) environment.
Levels of Organization
• Community – groups of different
populations that live together in a defined
area.
• Population – groups of individuals of same
species in same area.
• Species – group of organisms so similar that
they can mate and produce fertile offspring.
Levels of Organization
Biotic and Abiotic Factors
• Biotic – living
– Plants, Animals ,Mold,
Fungi, Bacteria, Protist
• Abiotic – Nonliving
– Sunlight, soil, wind, water,
temperature
• Habitat – the area where an
organism lives; includes both
biotic and abiotic factors.
Ecological Methods
1. Observation – 1st step to
designing an experiment
2. Experiment – test
hypotheses; imitate &
manipulate
3. Modeling – make models
based on observation &
experiment
•
Helps make future predictions
3.2 ENERGY FLOW
(Autotrophs and Heterotrophs)
• One of the most important factors
to determine capacity to sustain life is
Energy Flow
Autotrophs (producers)
• Can trap light energy to produce food (organic
molecules)
– Plants
– Some protists
– Some bacteria
• Photosynthesis – captures solar energy and
converts it to chemical energy
SUN
6CO2 + 6H2O
C6H12O6 + 6O2
• Chemosynthesis – Chemical energy used to produce carbohydrates
Heterotrophs (consumers)
• Can’t trap energy directly;
must acquire it from other
organisms
–
–
–
–
Herbivores – plants
Carnivores – animals
Omnivores – both
Detritivores – remains of
dead plants & animals
– Decomposers – break down
organic matter
3.2 Energy Flow in
Ecosystems
• Food Chains and Food Webs
Food Chains and Food Webs
SUN
Autotrophs
Heterotroph
1. Food Chain – energy trapped by producers
passed on when organisms eat and are eaten
2. Food Web – relationship more complex than a
chain
Trophic Levels and Ecological
Pyramids
• Trophic Levels – each step in a food chain/web
Ex: producers, then consumers
• Ecological Pyramids – shows relative amount of energy
at each level (10% rule)
• Biomass – total amount of living tissue within a trophic
level
Trophic Levels and Ecological
Pyramids
3.4 Cycles of Matter
*Recycle Matter*
Carbon Cycle
• Photosynthesis – uses CO2 from atmophere
– Happens in the CHLOROPLAST
6CO2 + 6H2O
C6H12O6 + 6O2
• Respiration – returns CO2 to atmoshere
– Happens in the MITOCHONDRIA
C6H12O6 + O2
H2O + CO2
Carbon Cycle
The Carbon Cycle
1. Volcanoes, respiration, fossil fuels, and
decomposition add CO2 to atmosphere.
2. Plants take CO2 and make carbohydrates
3. Plants are eaten by animals and carbohydrates
are passed through the food chain.
4. As the animal breathes and eventually dies and
decomposes CO2 is return to atmosphere.
Water Cycle
Water Cycle
1. Water enters the atmosphere by:
•
•
Evaporation – water changes from a liquid to a
gas
Transpiration – Evaporation through leaves
2. As water rises it cools condenses into tiny
droplets that form clouds.
3. Droplets returns to Earth as precipitation.
4. Water enters the rivers, ground water, ocean
or plant roots to restart cycle.
Nitrogen Cycle
Nitrogen Cycle
1. Nitrogen gas makes up 78% of atmosphere
2. Nitrogen Fixation: bacteria take nitrogen gases
and turn it into ammonia, nitrite, and nitrate.
3. Plants and animals use nitrate to make amino
acids.
4. Animal dies and decomposes returning nitrates
to the soil.
5. Denitrification: other bacteria convert nitrates
into nitrogen gas.
The Phosphate Cycle
• Phosphate – parts of DNA/RNA
• Found in rocks that are worn down
• Washes into rivers/streams/oceans for
marine organisms
• Taken in by plants and turned into organic
compounds
Nutrient Limitation
• Primary Productivity – the rate at which
organic molecules are created by producers
• If nutrients are in short supply, they are
called LIMITING NUTRIENTS
Ex: Nitrogen is often limiting in water; if
there is suddenly as input of N (fertilizer
runoff), organisms can grow rapidly (Algal
Bloom)
Discussion questions:
1. How many stops can you make on your trip?
2. Will your journey ever end?
3. Was everyone’s journey the same? Why not?
4. What would happen if a farmer used too much
fertilizer? (In this game, that would mean that
everyone started from the fertilizer station at the
same time.)
5. Livestock farming creates a large amount of
animal waste. How would this affect the nitrogen
cycle?