Slide 1
What is Ecology?
The Scientific study of interactions
among & between organisms and
their environment.
Chapter 3, 4 and 5 in the Prentice Hall Biology Book
Slide 2
The Biosphere
Extends to 8 km above
the earth’s surface
The part of the environment that
hosts existance. (includes
land,water, air.)
Extends to 11 km below the
surface of the oceans.
Slide 3
Levels of Organization in
Ecology
• Species: Group of organisms so similar they
breed and produce offspring.
– ex. A bear
– A horse
• Populations: Groups of individuals that belong
to the same species in the same area
– . (Ex: den of bears)
Slide 4
Levels, cont.
• Community: Groups of different
populations living together in a
defined area.
– Ex: bears and elk in Yellowstone Natl. Park
• Ecosystem: Collection of all organisms
that live in a particular place together with
nonliving organisms.
– Ex: animals, plants, rivers, rocks
Slide 5
It takes Energy!
• All organisms need energy to survive.
The flow of energy through an ecosystem
is one of the MOST IMPORTANT facts
that determine if the system can sustain
life.
Slide 6
And Energy Starts with…
Sunlight is the main energy source
for life on earth!
Chloroplasts!
Sun’s energy
Carbon Dioxide + water + energy
 glucose + oxygen
6 CO2 + 6 H2O  C6H12O6 +6 O2
Slide 7
We classify based on energy…
• Autotrophs
– Can make their
own food!
(plants)
Also called
PRODUCERS
• Heterotroph
– Can’t make their
own food.
(animals)
Also called
CONSUMERS!
Slide 8
Autotrophs/Producers
• plants, some algae, some bacteria. These
organisms can capture energy directly from the
sun or chemicals and use this energy to produce
their own food. Also called Producers.
– Photosynthesis- An autrophoph that uses light
energy to power chemical reactions which converts
CO2 and water into O2 and sugars and starches.
• Ex plants
– Chemosynthesis- An autotroph that produces food
in the absence of light. Relies on energy within
chemical bonds of inorganic molecules.
• ex: some bacteria
Slide 9
Heterotophs/Consumers
• Consumers- cannot harness energy directly from
the physical environment.
a. Heteretrophs- Can’t make their own food.
(animals)
1. Herbivores- Animals that eat plants. (cows, deer)
2. Carnivores- Animals that eat other animals
(Snakes, owls)
3. Omnivores- Eat both plants and animals. (humans,
bears)
4. Decomposers- Group of heterotrophs that break
down organic matter. (bacteria/ fungi)
Slide 10
Herbivores
Name all these
herbivores!
Slide 11
Omnivores
Name these common omnivores. Add
two of your own examples.
Slide 12
Carnivores
Name all these
Carnivores!
What’s your favorite
carnivore?
Slide 13
Decomposers and Scavengers
• Decomposers and scavengers break down
dead plants and animals. They also break
down the waste (poop) of other organisms.
Decomposers are very important for any
ecosystem. If they weren't in the ecosystem,
the plants would not get essential nutrients,
and dead matter and waste would pile up.
• There are two kinds of decomposers,
scavengers and decomposers.
Slide 14
Decomposers
Slide 15
Food Chains
• Food Chain- Series of steps in the
ecosystem in which organisms transfer
energy by eating or being eaten.
Slide 17
Food Webs
• Food Web- Network of interactions that
link all the food chain in an ecosystem.
• Tropic Level- Each step in a food chain.
Producers make up the first level,
consumers make up the higher levels.
Each level depends on the lower level for
energy.
Slide 18
Cycles of Matter
Matter is recycled within and
between ecosystems.
Slide 19
1. The Water Cycle• All living things require water for survival! Water
changes from liquid to gas in two ways:
– a. evaporation- liquid to a gas
– b. transpiration- evaporation from leaves.
• Where does the water go after it forms puddles
on the pavement? Evaporation or condensation?
• Wet clothes are put into a dryer and come out
dry. Where does the water go?
Slide 20
The Water Cycle Diagram
Slide 21
Three Nutrient Cycles every living
organism must have nutrients to survive
1.
Carbon Cycle- Carbon is the key ingredient
in living tissues. CO2 in the air, calcium
carbonate in the soil and animal bones.
2. Nitrogen Cycle- Nitrogen builds amino acids
to make proteins. Atmosphere and soil contain
Nitrogen.
3. 3. Phosphorus Cycle- Phosphorus is
essential to living organisms because it forms
part of the DNA and RNA.
Slide 22
The Carbon Cycle
• Watch the
Carbon Cycle
Animation!
– Answer the
questions on
your notes
– Take the Quiz!
- Carbon is the key ingredient in living tissues. CO2 in the air, calcium
carbonate in the soil and animal bones.
Slide 23
Global Nitrogen
• Nitrogen Fixation- Process of
converting nitrogen gas into ammonia.
Plants can convert this into proteins.
• Denitrification- Process that releases the
nitrogen back into the atmosphere. Result
of decomposition
Nitrogen Cycle
Slide 24
Slide 25
Phosphorus Cycle• Phosphorus is essential to living
organisms because it forms part of the
DNA and RNA.
• See Diagram on the next slides
Slide 26
Slide 27