1. Chapter 2 Principles of Ecology
Section 1: Organisms and Their Relationships
Section 2: Flow of Energy in an Ecosystem
Section 3: Cycling of Matter

2. Chapter 2
Principles of Ecology
2.1 Organisms and Their Relationships
Ecology
Scientific discipline in which the relationships among living organisms and the interaction the organisms have with their environments are studied
Ecologists observe, experiment, and model using a variety of tools and methods.

3. A thin layer around Earth that supports life
Chapter 2
Principles of Ecology
2.1 Organisms and Their Relationships
The Biosphere
A thin layer around Earth that supports life
Extends several kilometers above the Earth’s surface
Extends several kilometers below the ocean’s surface

4. The Biosphere 2.1 Organisms and Their Relationships Chapter 2
Principles of Ecology
2.1 Organisms and Their Relationships
The Biosphere

5. Living factors in an organism’s environment
Chapter 2
Principles of Ecology
2.1 Organisms and Their Relationships
Biotic Factors
Living factors in an organism’s environment
Ex: animals, plants, algae, etc.
Abiotic Factors
Nonliving factors in an organism’s environment
Organisms adapt to survive in the abiotic factors present in their natural environment.
Ex: rocks, dirt, air currents, temperature, moisture, light, etc.

6. Levels of Organization
Chapter 2
Principles of Ecology
2.1 Organisms and Their Relationships
Levels of Organization
Levels increase in complexity as the numbers and interactions between organisms increase.
atoms
molecules
organelles
cells
tissues
organs
organ
systems
organism
population
biological community
ecosystem
biome
biosphere

7. 2.1 Organisms and Their Relationships
Definitions
Atoms
Molecules
Organelles
Cells
Tissues
Organs
Organ System
Organism

8. Chapter 2
Principles of Ecology
2.1 Organisms and Their Relationships
Organisms of a single species that share the same geographic location at the same time make up a population.
A biological community is a group of interacting populations that occupy the same geographic area at the same time.

9. Chapter 2
Principles of Ecology
2.1 Organisms and Their Relationships
An ecosystem is a biological community and all of the abiotic factors that affect it.
A biome is a large group of ecosystems that share the same climate and have similar types of communities.

10. Ecosystem Interactions
Chapter 2
Principles of Ecology
2.1 Organisms and Their Relationships
Ecosystem Interactions
A habitat is an area where an organism lives.
A niche is the role (job) or position that an organism has in its environment.
Types of Niches
Producer
Primary Consumer
Secondary Consumer
Decomposer
Scavenger

11. Community Interactions
Chapter 2
Principles of Ecology
2.1 Organisms and Their Relationships
Community Interactions
Competition
Occurs when more than one organism uses a resource at the same time
Predation
Many species get their food by eating other organisms.

12. Symbiotic Relationships
Chapter 2
Principles of Ecology
2.1 Organisms and Their Relationships
Symbiotic Relationships
The close relationship that exists when two or more species live together (means “living together”)
Mutualism
Commensalism
Parasitism
Predation

13. 2.1 Organisms and Their Relationships
Symbiotic Relationship
Organism #1
Organism #2
Mutualism +
Commensalism O
Parasitism -
Predation
- (killed)
Key: + = Helped/Benefited
- = Harmed
O = Unaffected

14. 2.2 Flow of Energy in an Ecosystem
NUTRITION
The ultimate source of energy is the SUN, which supplies the energy that fuels life.

15. Energy in an Ecosystem (Types of Niches)
Chapter 2
Principles of Ecology
2.2 Flow of Energy in an Ecosystem
Energy in an Ecosystem (Types of Niches)
The Producers
Autotrophs
- Organism that collects energy from sunlight or inorganic substances to produce food
- Plant’s use the sun’s energy to manufacture food in a process called photosynthesis

16. Energy in an Ecosystem (Types of Niches)
Chapter 2
Principles of Ecology
2.2 Flow of Energy in an Ecosystem
Energy in an Ecosystem (Types of Niches)
The Consumers
- Heterotrophs
Organism that gets it energy requirements by
consuming other organisms
A lynx is a heterotroph.

17. 2.2 Flow of Energy in an Ecosystem
Primary Consumers: an organism that gets its energy from producers (plants); usually called herbivores
Secondary Consumers: a consumer that gets its energy from other consumers; usually called carnivores
Types of consumers
Herbivores
Carnivores
Omnivores
Scavengers: animals that feed on animals that have already died (ex: vultures, ants, beetles)
Decomposers: organisms that break down and absorb nutrients from dead organisms (ex: fungi, bacteria)

18. Detritivores eat fragments of dead matter in an
Chapter 2
Principles of Ecology
2.2 Flow of Energy in an Ecosystem
ecosystem, and
return nutrients
to the soil, air,
and water where
the nutrients can
be reused by
organisms.
Detritivores eat fragments of dead matter in an
Fungus

19. Food Chains 2.2 Flow of Energy in an Ecosystem
Chapter 2
Principles of Ecology
2.2 Flow of Energy in an Ecosystem
Food Chains
A food chain is a simple model that shows how energy flows through an ecosystem.
Arrows indicate the direction in which energy is transferred
Usually 3-5 links; energy is lost in every transfer
Energy is lost to the environment as HEAT

20. Chapter 2
Principles of Ecology
2.2 Flow of Energy in an Ecosystem
Food Webs
A food web is a model representing the many interconnected food chains and pathways in which energy flows through a group of organisms.

21. Food chains and food webs model the energy flow through an ecosystem.
Chapter 2
Principles of Ecology
2.2 Flow of Energy in an Ecosystem
Models of Energy Flow
Food chains and food webs model the energy flow through an ecosystem.
Each step in a food chain or food web is called a trophic level.

23. Chapter 2
Principles of Ecology
2.2 Flow of Energy in an Ecosystem
Ecological Pyramids
A diagram that can show the relative amounts of energy, biomass, or numbers of organisms at each trophic level in an organism

24. Cycles in the Biosphere
Chapter 2
Principles of Ecology
2.3 Cycling of Matter
Cycles in the Biosphere
Energy is transformed into usable forms to support the functions of an ecosystem.
The cycling of nutrients in the biosphere involves both matter in living organisms and physical processes found in the environment such as weathering.

25. Chapter 2
Principles of Ecology
2.3 Cycling of Matter
The Water Cycle

26. Freshwater constitutes only about 3 percent of all water on Earth.
Chapter 2
Principles of Ecology
2.3 Cycling of Matter
Approximately 90 percent of water vapor evaporates from oceans, lakes, and rivers; 10 percent evaporates from the surface of plants through a process called transpiration.
Freshwater constitutes only about 3 percent of all water on Earth.
About 69 percent of all freshwater is found in ice caps and glaciers.

27. The Carbon and Oxygen Cycles
Chapter 2
Principles of Ecology
2.3 Cycling of Matter
The Carbon and Oxygen Cycles

28. Carbon and oxygen often make up molecules essential for life.
Chapter 2
Principles of Ecology
2.3 Cycling of Matter
Carbon and oxygen often make up molecules essential for life.
Carbon and oxygen recycle relatively quickly through living organisms.

29. Organic matter converted to peat, coal, oil, or gas deposits (carbon)
Chapter 2
Principles of Ecology
2.3 Cycling of Matter
Long-term Cycle
Organic matter converted to peat, coal, oil, or gas deposits (carbon)
Calcium carbonate (carbon and oxygen)
Short-term Cycle
Burning fossil fuels (carbon)

30. Chapter 2
Principles of Ecology
2.3 Cycling of Matter
The Nitrogen Cycle
The capture and conversion of nitrogen into a form that is useable by plants is called nitrogen fixation.

31. Chapter 2
Principles of Ecology
2.3 Cycling of Matter
Nitrogen enters the food web when plants absorb nitrogen compounds from soil.
Consumers get nitrogen by eating plants or animals that contain nitrogen.

32. Nitrogen is returned to the soil in several ways:
Chapter 2
Principles of Ecology
2.3 Cycling of Matter
Nitrogen is returned to the soil in several ways:
Animals urinate.
Organisms die.
Organisms convert ammonia into nitrogen compounds.
Denitrification

33. The Phosphorus Cycle 2.3 Cycling of Matter Chapter 2
Principles of Ecology
2.3 Cycling of Matter
The Phosphorus Cycle

34. Chapter 2
Principles of Ecology
2.3 Cycling of Matter
Short-term Cycle
Phosphorus is cycled from the soil to producers and then from the producers to consumers.
Long-term Cycle
Weathering or erosion of rocks that contain phosphorus slowly adds phosphorus to the cycle.

35. Three Types of Sampling Methods
1.) Random Point Survey
A random point survey uses randomly-selected points in a study are to characterize a site
Population selected in a manner that ensures that each member of the population has an equal chance of being selected
More points = more accurate data

36. Three Types of Sampling Methods
2.) Quadrat Survey
A quadrat is a plot of a fixed size in which density of objects can be measured
Plots usually circular or Squared
Main goal is that scientists want to know the number of objects per unit area (density)

37. Three Types of Sampling Methods
3.) Core Sample
A core sample is obtained by inserting a hollow tube-shaped device into the bottom sediments to retrieve a tube full of sediments with its accompanying organisms

38. Chapter Resource Menu Chapter Diagnostic Questions
Principles of Ecology
Chapter Resource Menu
Chapter Diagnostic Questions
Formative Test Questions
Chapter Assessment Questions
Standardized Test Practice
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Vocabulary
Animation
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39. Chapter 2
Principles of Ecology
Chapter Diagnostic Questions
The act of one organism consuming another organism for food is _______.
predation
parasitism
commensalism
mutualism D C B A
CDQ 1

40. from an autotroph to a heterotroph from a heterotroph to an autotroph
Chapter 2
Principles of Ecology
Chapter Diagnostic Questions
Identify how energy flows through an ecosystem in a typical food chain.
from an autotroph to a heterotroph
from a heterotroph to an autotroph
from a carnivore to an herbivore
from an omnivore to an herbivore D C B A
CDQ 2

41. Chapter 2
Principles of Ecology
Chapter Diagnostic Questions
What is a chemical substance that an organism must obtain from its environment to survive?
biomass
energy
matter
nutrient D C B A
CDQ 3

42. Which are biotic factors in a forest environment?
Chapter 2
Principles of Ecology
2.1 Formative Questions
Which are biotic factors in a forest environment?
plants and microscopic organisms living
pH and salt concentration of the soil
sunlight, soil type and soil nutrients
temperature, air currents and rainfall D C B A
FQ 1

43. Chapter 2
Principles of Ecology
2.1 Formative Questions
What is the name for a group of interacting populations that occupy the same area at the same time?
ecosystem
habitat
biological community
biotic collection A B C D
FQ 2

44. all of the biotic factors in an ecosystem
Chapter 2
Principles of Ecology
2.1 Formative Questions
Which defines habitat?
all of the biotic factors in an ecosystem
an area where an organism lives
an area in which various species interact
the role or position that an organism has D C B A
FQ 3

45. What type of organism is the foundation of all ecosystems?
Chapter 2
Principles of Ecology
2.2 Formative Questions
What type of organism is the foundation of all ecosystems?
autotroph
herbivore
heterotroph
decomposer D C B A
FQ 4

46. How do detritivores obtain their energy in an ecosystem?
Chapter 2
Principles of Ecology
2.2 Formative Questions
How do detritivores obtain their energy in an ecosystem?
They feed on fragments of dead plants and animals
They feed on organisms by releasing digestive enzymes.
They get energy from inorganic substances to make food.
They use chlorophyll to capture energy from the sun. D C B A
FQ 5

47. Chapter 2
Principles of Ecology
2.2 Formative Questions
Which type of organism exists at all trophic levels except the first trophic level?
carnivores
herbivores
autotrophs
heterotrophs D C B A
FQ 6

48. What type of organism returns nutrients to an ecosystem?
Chapter 2
Principles of Ecology
2.3 Formative Questions
What type of organism returns nutrients to an ecosystem?
decomposer
primary producer
secondary producer
top level consumer D C B A
FQ 7

49. Chapter 2
Principles of Ecology
2.3 Formative Questions
What type of scientist studies water found underground, in the atmosphere, and on the surface of the earth?
biochemist
ecologist
geologist
hydrologist D C B A
FQ 8

50. Chapter 2
Principles of Ecology
2.3 Formative Questions
Which biogeochemical cycle involves evaporation, transpiration, precipitation and runoff?
carbon cycle
nitrogen cycle
phosphorus cycle
water cycle D C B A
FQ 9

51. combustion of fossil fuels deposition of dead material
Chapter 2
Principles of Ecology
2.3 Formative Questions
Which process in this cycle converts carbon dioxide and water into carbohydrates?
photosynthesis
respiration
combustion of fossil fuels
deposition of dead material D C B A
FQ 10

52. Use the diagram to compare and contrast biotic
Chapter 2
Principles of Ecology
Chapter Assessment Questions
Use the diagram to compare and contrast biotic
and abiotic factors. Give examples of each.
CAQ 1

53. Answer: Biotic factors include the living factors in an organism’s
Chapter 2
Principles of Ecology
Chapter Assessment Questions
Answer: Biotic factors include the living
factors in an organism’s
environment, such as animals,
reptiles, plants, and microscopic
organisms. Abiotic factors are the
nonliving factors, such as water
temperature, rainfall, soil, and
available nutrients.
CAQ 2

54. Use the image below to explain how decomposers
Chapter 2
Principles of Ecology
Chapter Assessment Questions
Use the image below to explain how decomposers
supply phosphorus to soil, groundwater, oceans,
lakes, ponds, and rivers.
CAQ 3

55. Answer: All organisms contain phosphorus.
Chapter 2
Principles of Ecology
Chapter Assessment Questions
Answer: All organisms contain phosphorus.
When organisms die or produce
waste products, decomposers
return the phosphorus to the soil
where it can be used again.
CAQ 4

56. The diagram shows how carbon cycles through the environment.
Chapter 2
Principles of Ecology
Chapter Assessment Questions
The diagram shows
how carbon cycles
through the
environment.
Describe how
photosynthesis is
involved in the
carbon cycle.
CAQ 5

57. Answer: During photosynthesis, green plants and algae convert carbon
Chapter 2
Principles of Ecology
Chapter Assessment Questions
Answer: During photosynthesis, green
plants and algae convert carbon
dioxide and water to carbohydrates
and release oxygen into the air.
The plants use the carbohydrates
for energy. Carbon dioxide is
released back into the air through
cellular respiration.
CAQ 6

58. Chapter 2
Principles of Ecology
Standardized Test Practice
In what type of activity would you most expect an ecologist to be involved?
identifying and classifying various species of insects in an ecosystem
locating fossils of distinct species of turtles in a geographical area
observing the relationships that woodpeckers have with other species in their environment
studying the internal organs of a seal to learn how it survives in its environment D C B A
STP 1

59. Chapter 2
Principles of Ecology
Standardized Test Practice
Certain types of tropical orchids use trees for support in order to grow higher and obtain more light. This neither harms nor benefits the tree. What type of symbiotic relationship is this?
commensalism
competition
mutualism
parasitism D C B A
STP 2

60. Chapter 2
Principles of Ecology
Standardized Test Practice
If an ecologist finds that the long-tailed weasels have disappeared from the desert community, she should conclude that there will be a decrease in the population of coyotes. B A
true
false
STP 3

61. Why is this mouse classified as an omnivore?
Chapter 2
Principles of Ecology
Standardized Test Practice
Why is this mouse classified as an omnivore?
It is consumed by
snakes.
It consumes
grasshoppers.
It is a third-level
consumer.
It consumes both
grasshoppers and D C B A
STP 4

62. Which process returns nitrogen to the food web?
Chapter 2
Principles of Ecology
Standardized Test Practice
Which process returns nitrogen to the food web?
decomposition
denitrification
nitrification
nitrogen fixation D C B A
STP 5

63. Section 1 Vocabulary ecology biosphere biotic factor abiotic factor
Chapter 2
Principles of Ecology
Vocabulary
Section 1
ecology
biosphere
biotic factor
abiotic factor
population
biological community
ecosystem
biome
habitat
niche
predation
symbiosis
mutualism
commensalism
parasitism

64. Section 2 Vocabulary autotroph heterotroph herbivore carnivore
Chapter 2
Principles of Ecology
Vocabulary
Section 2
autotroph
heterotroph
herbivore
carnivore
omnivore
detritivore
trophic level
food chain
food web
biomass

65. Section 3 Vocabulary matter nutrient biogeochemical cycle
Chapter 2
Principles of Ecology
Vocabulary
Section 3
matter
nutrient
biogeochemical cycle
nitrogen fixation
denitrification