Environmental Science

1
Environmental Science

• Chapter 5 Lecture Notes
• How Ecosystems Work

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Chapter 5 Targets

• 1. I can explain how photosynthesis and cellular
  respiration are related.
• 2. I can explain the difference between
  autotrophs and heterotrophs and list examples of
  each.
• 3. I can explain the difference between a food
  chain and a food web
• 4. I can diagram a food chain with at least four
  members and label the trophic level for each
  member.
• 5. I can explain the 10 Rule using an energy
  pyramid

3
Life Depends on the Sun

• Energy from sun enters ecosystem when plants use
  sunlight to make sugar molecules.
• ___________ process where plants, algae, and
• some bacteria use _________, _____________,
• and ________ to produce _____________ and
• ______________.

T1
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Burning the Fuel

• ________________ process when cells use
• energy from _____________ oxygen
• combines with glucose to form __________ and
  carbon dioxide.
• Cellular respiration occurs inside cells of most
  organisms.
• How are photosynthesis and cellular respiration
  related?

T1
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From Producers to Consumers

• ________ organism that can _______ organic
  molecules from inorganic molecules
• also called __________________
• ___________ organism that ________ other
  organisms or organic matter instead of producing
  its own nutrients
• also called ________________

T2
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Exception to the Rule

• Deep-ocean communities of worms, clams, crabs,
  mussels, and barnacles, live in total darkness on
  ocean floor, where photosynthesis cannot occur.
• Producers are ______________ that use
• __________________ in water
• Other organisms eat the bacteria

T2
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What Eats What?

• Trophic Levels
• Types of Consumers
• ______________
• ______________
• ______________
• ______________

T2
8
Food Chains

• Food chain ____________ in which __________ is
  transferred from one organism to the next

T3
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Food Webs

• Food web shows _________ feeding relationships
  possible in an _________.

T3
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Trophic Levels

• Trophic level one of the ________ in a food
  chain or food pyramid examples include producers
  and primary, secondary, and tertiary consumers.

T4
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Comprehension Check

• On the food web, label the following
• -Producers (Autotrophs)
• -Carnivores
• -Herbivores
• -Omnivores
• -1st Order Consumers
• -2nd Order Consumers
• -3rd Order Consumers
• -4th Order Consumers

4th
3rd
2nd
3rd
2nd
3rd
1st
2nd
1st
2nd
1st
1st
producer
producer
12
Trip to Neptune

• The crew of a space shuttle bound for Neptune is
  able to grow wheat and corn in its spacecraft.
  Would they be able to support more crew members
  by (choose one answer below)
• 1. Eating the corn and wheat
• 2. Feeding the corn and wheat to chickens,
  then eating the chickens
• 3. Feeding the corn and wheat to chickens,
  then eating the chickens eggs

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Trophic Levels

• Each time energy is transferred, some is ________
  as ________.
• __________ energy is available to organisms at
  higher trophic levels.
• One way to visualize this is with an energy
  pyramid.
• Energy loss limits number of trophic levels in an
  ecosystem
• 10 Rule

Energy Pyramid
T5
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Other Types of Pyramids
Numbers Pyramid
Biomass Pyramid
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Trip to Neptune

• The crew of a space shuttle bound for Neptune is
  able to grow wheat and corn in its spacecraft.
  Would they be able to support more crew members
  by (has your answer changed?)
• 1. Eating the corn and wheat
• 2. Feeding the corn and wheat to chickens,
  then eating the chickens
• 3. Feeding the corn and wheat to chickens,
  then eating the chickens eggs

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Comprehension Check

• How does energy move through most ecosystems on
  Earth?
• A. From the sun to consumers to producers
• B. From the sun to producers to consumers to
  decomposers
• C. From the sun to decomposers to producers to
  consumers
• D. From the sun to consumers to producers back
  to consumers

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Comprehension Check

• Which of the following statements indicates an
  understanding of the importance of energy to life
  on Earth?
• A. Many organisms on Earth require energy for
  their life processes.
• B. All organisms on Earth require energy for
  their life processes.
• C. Energy is required for the most important
  life processes on Earth.
• D. The most important organisms on Earth require
  energy for their life processes.

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Chapter 5 Targets

• 6. I can list and describe the three stages of
  the carbon cycle.
• 7. I can identify two ways humans are affecting
  the carbon cycle.
• 8. I can list the three stages of the nitrogen
  cycle.
• 9. I can describe the role that nitrogen-fixing
  bacteria and decomposers play in the nitrogen
  cycle.
• 10. I can list the stages of the phosphorus
  cycle.
• 11. I can explain how the excess use of
  fertilizer can affect the nitrogen and phosphorus
  cycles.

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The Carbon Cycle

• Carbon cycle movement of carbon from
  _____________ environment into living things and
  back
• Carbon main component of ____________, fats, and
  carbohydrates, which make up all organisms.

T6
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How Humans Affect the Carbon Cycle

• 1. Humans burn ____________, releasing carbon
  into atmosphere.
• 2. Humans destroy __________, preventing uptake
  of CO2 through photosynthesis
• __________ levels of CO2 contribute to global
  warming.
• Remember the difference between global warming
  and the greenhouse effect!

T7
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Comprehension Check

• What is the process that breaks down food to
  yield energy called?
• A. cellular digestion
• B. cellular respiration
• C. decomposition
• D. photosynthesis

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The Nitrogen Cycle

• Nitrogen cycle process when nitrogen circulates
  between ______, soil, water, plants, and
  ____________ in an ecosystem.
• All organisms need nitrogen to build
  ______________
• Nitrogen makes up what of air we breathe?

T8
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Fixing Nitrogen

• Nitrogen must be ____________ before organisms
  can use it.
• Nitrogen-fixing bacteria convert atmospheric
  nitrogen into useable nitrogen.
• Bacteria live within roots of
  plants called _____________, which
  include beans, peas, and clover.
• Bacteria use ________ given to them by
  legumes to
  produce nitrogen compounds
  such as _____________.
• ______________ also fixes a small amount of
  nitrogen
• Excess nitrogen fixed by bacteria is released
  into soil.

T9
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Decomposers and the Nitrogen Cycle

• Nitrogen stored in bodies of living things is
  returned to nitrogen cycle once they die.
• Decomposers break down decaying plants and
  animals and their wastes.
• After decomposers return nitrogen to soil,
  ____________ transform small amounts of the
  nitrogen into ____________, which returns to
  atmosphere to complete nitrogen cycle.

T9
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The Nitrogen Cycle
?
?
?
?
?
T8
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The Phosphorus Cycle

• Phosphorus makes up many molecules in the cells
  of organisms.
• Plants get phosphorus from ____________ and
  __________
• Animals get phosphorus by ______________ or other
  animals that have eaten plants.
• Phosphorus cycle cyclic movement of phosphorus
  in different chemical forms from environment to
  organisms and back to environment.

T10
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The Phosphorus Cycle
?
?
?
?
T10
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Fertilizers and the Nitrogen and Phosphorus Cycles

• Fertilizers contain both nitrogen (N)
  and phosphorus (P)
• Excess fertilizer can enter land and aquatic
  ecosystems through runoff.
• Excess N and P cause rapid growth of ____________
• Excess algae deplete aquatic ecosystems of
  nutrients such as _________, which fish and other
  aquatic organisms need

T11
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Comprehension Check

• What role do bacteria play during the nitrogen
  cycle?
• A. Bacteria store nitrogen in wastes.
• B. Bacteria convert nitrogen into water.
• C. Bacteria turn nitrogen into phosphates.
• D. Bacteria transform nitrogen into usuable
  molecules.

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Chapter 5 Targets

• 12. I can define and list two examples of
  ecological succession.
• 13. I can explain how a pioneer species
  contributes to ecological succession.
• 14. I can describe how lichens contribute to
  primary succession.

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Ecological Succession

• Ecosystems are constantly changing.
• Ecological succession gradual process of
  ________ and replacement of types of ________ in
  a community.
• Each _____ community often makes it _________ for
  the previous community to survive.

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Primary Succession

• Primary succession begins in area that
  previously did ____ support life
• Rocks
• Cliffs
• Sand dunes
• Areas that have had volcanic eruptions
• First species to colonize bare rock will probably
  be __________ and ________, which can live
  without soil.
• growth of lichens breaks down rock, which with
  the action of water, begins to form soil.

T13/T14
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Secondary Succession

• Secondary succession occurs where an ecosystem
  ____________________________.
• One community replaces another that was partially
  or totally _____________.
• Can occur in ecosystems that have been disturbed
  by humans, animals, or natural processes such as
  ________, ___________, fires or ____________.

T12
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Ecological Succession Organisms

• ________________ species that colonizes
  uninhabited area and starts ecological cycle for
  other species.
• Lichens
• Bacteria
• ____________ final, stable community in
  equilibrium with environment.
• Even though a climax community may change in
  small ways, this type of community may remain the
  same through time if not disturbed.

T12
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Ecological Succession
T12
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Comprehension Check

• Which of the following shows an effect of the
  increased burning of fossil fuels on the carbon
  cycle?
• A. More carbonates remain in fossil fuels.
• B. More carbon dioxide is absorbed by
  organisms.
• C. More carbon dioxide is absorbed by the
  atmosphere.
• D. More carbohydrates remain buried deep
  in the ground.

37
Chapter 5 Targets

• 15. I can define BIOLOGICAL MAGNIFICATION of a
  pesticide and identify which organisms in a
  pesticide would be harmed the most by it.
• 16. I can describe difference between a
  BIODEGRADABLE and a NONBIODEGRADABLE pesticide.

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Biodegradable vs. Non-Biodegradable Pesticides

• See Pesticide Web Quest Website 3

Biodegradable Pesticides Non-Biodegradable Pesticides
Definition Can naturally be broken down into safe molecules Can NOT be broken down naturally, so they remain poisonous in an ecosystem
Examples -DDT -Chlordane (termites)
Problems with Using -Organisms more easily develop a resistance to them -Remain in ecosystems for decades -Build up in food chains -Biological Magnification
T16
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Biological Magnification

• See Pesticide Web Quest Website 4

T15