1. Lesson 1 Ecosystems and Biomes Lesson 2 Populations and Communities
Chapter Introduction
Lesson 1 Ecosystems and Biomes
Lesson 2 Populations and Communities
Lesson 3 Energy and Matter
Chapter Wrap-Up
Chapter Menu

2. How do living things interact with and depend on the other parts of an ecosystem?
Chapter Introduction

3. Lesson 1 Reading Guide - KC
Ecosystems and Biomes
What are ecosystems?
What are biomes?
What happens when environments change?
Lesson 1 Reading Guide - KC

4. Lesson 1 Reading Guide - Vocab
Ecosystems and Biomes
ecosystem
abiotic factor
biotic factor
population
community
biome
succession
Lesson 1 Reading Guide - Vocab

5. What are ecosystems?
Ecology is the study of how organisms interact with each other and with their environments.
Every organism on Earth lives in an ecosystem—the living and nonliving things in one place.
Different organisms depend on different parts of an ecosystem to survive.
Lesson 1-1

6. Abiotic Factors
Abiotic factors are the nonliving parts of an ecosystem.
Important abiotic factors include water, light, temperature, atmosphere, and soil.
The types and amounts of abiotic factors in an ecosystem help to determine which organisms can live there.
Lesson 1-2

7. Abiotic Factors (cont.)
All organisms need water to live, but some need more water than others. \
Some organisms, such as plants, require light energy to make food.
Ecosystems with more sunlight tend to have higher temperatures.
Lesson 1-2

8. Very few living things can survive in an ecosystem without oxygen in the atmosphere.
Earth’s atmosphere contains many gases that organisms need, such as water vapor, oxygen, carbon dioxide, and nitrogen.
The nutrient content, texture, moisture content, and depth of soil affect which organisms can live in an ecosystem.
Lesson 1-2

9. Biotic Factors
Biotic factors are all of the living or once-living things in an ecosystem.
A population is made up of all the members of one species that live in an area.
Organisms in a population interact and compete for food, shelter, and mates.
A community is all the populations that live together in the same place.
Lesson 1-3

10. Biotic Factors (cont.)
A biome is a large region on Earth with a specific climate, physical features, plants, and other organisms.
Biomes contain ecosystems, populations, and communities, as well as specific biotic and abiotic factors.
All biomes are part of the biosphere—the part of Earth that supports life—and can be described as either terrestrial or aquatic.
Lesson 1-3

11. Image by Reto Stockli, NASA/Goddard Space Flight Center
Image by Reto Stockli, NASA/Goddard Space Flight Center. Enhancements by Robert Simmon
Lesson 1-3

12. Biotic Factors (cont.)
Terrestrial means related to land, and aquatic means related to water.
Terrestrial biomes include forests, deserts, tundra, and grasslands.
Aquatic biomes include saltwater areas and freshwater areas.
Biomes, like communities, can affect each other.
Lesson 1-3

13. What happens when environments change?
Changes in the environment are caused by both natural processes and human actions.
Changes in an environment can occur slowly or rapidly and can have positive or negative effects.
Lesson 1-4

14. What happens when environments change? (cont.)
A volcanic eruption can cause sudden change in an ecosystem.
Succession is the gradual change from one community to another community in an area.
Lesson 1-4

15. Biotic factors are the living parts of an ecosystem.
Earth’s biosphere contains many different biomes.
Changes in a community can be very slow or very rapid.
Image by Reto Stockli, NASA/Goddard Space Flight Center. Enhancements by Robert Simmon
Lesson 1 - VS

16. Which of these refers to the nonliving parts of an ecosystem?
A. abiotic factors
B. biotic factors
C. biomes
D. populations
Lesson 1 – LR1

17. Which of these refers to all the populations that live together in the same place?
A. ecosystem
B. biosphere
C. community
D. biome
Lesson 1 – LR2

18. D. community development
The gradual change from one community to another community in an area is called what?
A. succession
B. population
C. interaction
D. community development
Lesson 1 – LR3

19. Lesson 2 Reading Guide - KC
Populations and Communities
How do individuals and groups of organisms interact?
What are some examples of symbiotic relationships?
Lesson 2 Reading Guide - KC

20. Lesson 2 Reading Guide - Vocab
Populations and Communities
limiting factor
biotic potential
carrying capacity
habitat
niche
symbiotic relationship
Lesson 2 Reading Guide - Vocab

21. Populations
A population is all the members of one species that live in an area at one time.
The area in which a population lives can be very large, such as the population of all the fish in the ocean, or very small, like fish in a lake.
The size of the population can increase or decrease in response to changes in abiotic or biotic factors in the environment.
Lesson 2-1

22. Populations can increase when individuals move into an area or when more individuals are born. They can decrease when individuals move away from an area or die.

23. The area a population lives in can be large or small.
Lesson 2-1

24. Populations (cont.)
Sometimes the size of a population changes because the ecosystem changes.
Population density describes the number of organisms in the population relative to the amount of space available.
If a population is very dense, organisms might have a hard time finding enough resources to survive.
Lesson 2-1

25. The size of a population can change in different ways.
Lesson 2-1

26. Limiting factors are factors that can limit the growth of a population
Limiting factors are factors that can limit the growth of a population. One factor is the lack of sufficient resources such as water; some individuals cannot survive under these circumstances.
Lesson 2-1

27. Populations (cont.)
Factors such as predation, competition, and disease are examples of limiting factors.
Biotic potential is the potential growth of a population if it could grow in perfect conditions with no limiting factors.
Carrying capacity is the largest number of individuals that can survive in an area over a long time.
Lesson 2-1

28. Populations (cont.)
The limiting factors of an area determine the area’s carrying capacity.
Overpopulation is when a population’s size grows beyond the ability of the area to support it.
This often results in overcrowding, a lack of resources, and an unhealthy environment.
Lesson 2-1

29. Communities
All the populations in the same area interact as a community.
Lesson 2-2

30. Communities (cont.)
Some populations might compete with each other for resources and space. They might also compete directly as they hunt each other for food or hide from predators.
Lesson 2-2

31. Symbiotic Relationships
Each population has different ways to stay alive and reproduce.
All of the populations in a community share a habitat, the physical place where a population or organism lives.
A niche is the unique ways an organism survives, obtains food and shelter, and avoids danger in its habitat.
Lesson 2-3

32. Symbiotic Relationships (cont.)
A symbiotic relationship is one in which two different species live together and interact closely over a long period of time.
These relationships can be beneficial to both organisms, beneficial to one and harmful to the other, or beneficial to one and neutral to the other.
Lesson 2-3

33. Types of Symbiotic Relationships
Mutualism—two species in a community benefit from the relationship.
Parasitism—one species (the parasite) benefits while another (the host) is harmed.
Commensalism—one species benefits and the other is neither helped nor harmed.
Lesson 2-3

34. The factors that limit the size a population of organisms can reach are called limiting factors.
A habitat is the physical environment where a population of organisms lives.
A symbiotic relationship exists when two different species of organisms live together in a close relationship over a long period of time.
Lesson 2 - VS

35. If a population’s rate of birth is as high as it can be while its death rate is as low as it can be, that population has reached which of these?
A. limiting factor
B. biotic potential
C. population density
D. carrying capacity
Lesson 2 – LR1

36. Which of these determines an area’s carrying capacity?
A. biotic potential
B. population
C. limiting factors
D. habitat
Lesson 2 – LR2

37. All of the populations in a community share which of these?
A. carrying capacity
B. habitat
C. biotic potential
D. limiting factor
Lesson 2 – LR3

38. Lesson 3 Reading Guide - KC
Energy and Matter
How does energy move in ecosystems?
How is the movement of energy in an ecosystem modeled?
How does matter move in ecosystems?
Lesson 3 Reading Guide - KC

39. Lesson 3 Reading Guide - Vocab
Energy and Matter
producer
consumer
food chain
food web
energy pyramid
Lesson 3 Reading Guide - Vocab

40. Energy Flow All life on Earth needs energy for cell processes.
Organisms get energy from food that they make using light or chemical energy or by eating other organisms.
When one organism eats another, the energy in the organism that is eaten is transferred to the organism that eats it.
Lesson 3-1

41. Energy Flow (cont.)
Energy travels through organisms, populations, communities, and ecosystems in a flow.
When energy moves in a flow it does not return to its source, as it does in cycles.
Lesson 3-1

42. Organisms and Energy
Scientists classify organisms by the way they get the energy they need to survive.
Producers change the energy available in their environment into food energy.
Some organisms, such as plants, are able to capture the Sun’s energy directly and convert it into energy-rich sugars that they use for food.
Lesson 3-2

43. Plant’s, algae, and some microorganisms use a chemical process called photosynthesis and changed light energy from the sun into food energy.
Lesson 3-2

44. Organisms and Energy (cont.)
A few organisms are able to capture energy from chemicals in the environment and make food by a process called chemosynthesis.
Other organisms cannot capture energy from sunlight or chemicals and must obtain their energy by eating food.
Organisms that cannot make their own food using the Sun must depend on organisms that can.
Lesson 3-2

45. Organisms and Energy (cont.)
Consumers use the energy and nutrients stored in other organisms for living and reproducing. They cannot make their own food.
Consumers are classified as herbivores, omnivores, carnivores, or detritivores, based on their diet.
Herbivores are animals that eat only producers, such as plants.
Lesson 3-2

46. Organisms and Energy (cont.)
Carnivores, such as lions, eat only other consumers.
Omnivores, such as human beings, are animals that eat both producers and other consumers.
Detritivores, including some insects, fungi, worms, bacteria, and protists, eat dead plant or animal material.
Lesson 3-2

47. Modeling Energy Flow
A food chain models how food energy moves from the environment to several organisms.
Lesson 3-3

48. Modeling Energy Flow (cont.)
Each stage of a food chain has less available food energy than the last one, because some food energy is converted to thermal energy, commonly called heat, and moves to the environment.
A food web is a model that shows several connected food chains.
Lesson 3-3

49. Food Web
Lesson 3-3

50. Modeling Energy Flow (cont.)
Food chains and food webs are models used to help understand how energy travels through a community.
Terrestrial and aquatic organisms can interact within a food chain or food web.
Food webs show that food energy can move through several different pathways.
Lesson 3-3

51. Modeling Energy Pyramids
An energy pyramid shows the amount of food energy available at each level of a community.
More food energy is available at the “base” of an energy pyramid, where producers are.
Lesson 3-4

52. Modeling Energy Pyramids (cont.)
Food energy from producers moves into consumers at the next level.
At each level of the pyramid, the amount of usable food energy decreases.
The top level of a food pyramid usually shows the carnivores in an ecosystem.
Lesson 3-4

53. This energy pyramid shows how energy flows from producers to consumers.
Lesson 3-4

54. Matter Cycles
Food, vitamins, minerals, and water that you need to live are examples of matter.
Matter is the physical material that makes up the world around you.
Most of the matter in your body is water, but your body also contains matter in other forms such as carbon and oxygen.
Lesson 3-5

55. Matter Cycles (cont.)
Unlike energy, matter does not flow, but moves in a cycle. It is used again and again throughout an ecosystem.
Lesson 3-5

56. Water Cycle
Lesson 3-5

57. Water Cycle (cont.)
In the water cycle, liquid water evaporates from oceans, rivers, and other bodies of water.
The water vapor, which is a gas, rises into the atmosphere, where it condenses and falls as rain or snow.
Lesson 3-5

58. Water Cycle (cont.)
Water moves across the surface of Earth in lakes, streams, and rivers, soaks into the ground, or is taken in by organisms, before eventually being released again, continuing the cycle.
Lesson 3-5

59. Oxygen also cycles through the environment.
Lesson 3-5

60. Oxygen Cycle Producers release oxygen gas and consumers take it in.
Plants release oxygen as a waste product of photosynthesis.
The oxygen enters the atmosphere, and many consumers take it in when they breathe in a process called respiration.
Lesson 3-5

61. Oxygen Cycle (cont.)
When organisms exhale, they release carbon dioxide, which contains oxygen and is a by-product of cellular respiration.
Some producers take in carbon dioxide, and the cycle continues.
Carbon is involved in photosynthesis and respiration.
Lesson 3-5

62. Carbon, a fundamental building block for all living things, also cycles through the environment.
Lesson 3-5

63. Carbon Cycle
When producers use carbon dioxide during photosynthesis, carbon is removed from the atmosphere.
Consumers eat these producers and release carbon back into the environment as a waste product
Producers again remove the carbon from the atmosphere as they continue making food, and the cycle continues.
Human activities such as the burning of fossil fuels add carbon to the atmosphere.
Lesson 3-5

64. A producer changes the energy available in the environment into food energy.
Consumers must use the energy and nutrients stored in other organisms for living and reproducing.
An energy pyramid shows how much food energy is available to organisms at each level of a community.
Lesson 3 - VS

65. A. producers C. omnivores B. consumers D. herbivores
Which type of organism changes the energy available in its environment into food energy it uses to live?
A. producers C. omnivores
B. consumers D. herbivores
Lesson 3 – LR1

66. Which type of model do scientists use to show several connected food chains?
A. an energy pyramid
B. a matter cycle
C. a food web
D. an energy flow
Lesson 3 – LR2

67. Three matter cycles include the oxygen cycle, water cycle, and which of these?
A. carbon dioxide cycle
B. energy cycle
C. vapor cycle
D. carbon cycle
Lesson 3 – LR3

68. 5. Most of the energy used by organisms on Earth comes from the Sun.
Do you agree or disagree?
5. Most of the energy used by organisms on Earth comes from the Sun.
6. Both nature and humans affect the environment.
Lesson 3 - Now

69. Interactive Concept Map Chapter Review Standardized Test Practice
Key Concept Summary
Interactive Concept Map
Chapter Review
Standardized Test Practice
Chapter Review Menu

70. Plants and animals, including humans, interact with each other and their environment to satisfy their basic needs. Energy flows from the Sun through producers to consumers.
The BIG Idea

71. Lesson 1: Ecosystems and Biomes
An ecosystem is made up of all the living and nonliving things in a location.
Biomes are large regions that have specific types of climate, physical characteristics, and organisms.
One environment changes into another in a process called succession.
Image by Reto Stockli, NASA/Goddard Space Flight Center. Enhancements by Robert Simmon
Key Concepts 1

72. Lesson 2: Populations and Communities
Organisms must compete with each other to obtain resources, such as food, water, and living space.
Symbiotic relationships include mutualism, parasitism, and commensalism.
Key Concepts 2

73. Lesson 3: Energy and Matter
Light energy from the Sun is changed into food energy by producers. Energy then moves through an ecosystem as organisms eat producers or other consumers.
Energy movement can be modeled simply as a food chain. A food web models the movement of energy through many food chains in an ecosystem.
Matter moves through ecosystems in cycles. Examples of matter cycles include the carbon, water, and oxygen cycles.
Key Concepts 3

74. Which of these is made up of all the living and nonliving things in a location?
A. biome
B. abiotic factor
C. biotic factor
D. ecosystem
Chapter Review – MC1

75. Which term refers to all of the living or once-living things in an ecosystem?
A. biotic factors
B. abiotic factors
C. biomes
D. organisms
Chapter Review – MC2

76. What do scientists call the potential growth of a population if it could grow in perfect conditions?
A. carrying capacity
B. niche
C. biotic potential
D. limiting factor
Chapter Review – MC3

77. What is the physical place where a population or organism lives?
A. carrying capacity
B. biotic potential
C. habitat
D. ecosystem
Chapter Review – MC4

78. Which model do scientists use to show how food energy moves from the environment to several organisms?
A. energy cycle
B. food chain
C. energy pyramid
D. matter cycle
Chapter Review – MC5

79. Which of these describes a large region on Earth with a specific climate, physical features, plants, and other organisms?
A. abiotic factor
B. biome
C. ecosystem
D. community
Chapter Review – STP1

80. What are the nonliving parts of an ecosystem?
A. abiotic factors
B. biotic factors
C. biomes
D. populations
Chapter Review – STP2

81. Which term refers to the largest number of individuals that can survive in an area over a long time?
A. biotic potential
B. carrying capacity
C. limiting factor
D. habitat
Chapter Review – STP3

82. What is the number of organisms in the population relative to the amount of space available?
A. population density
B. organism density
C. relative population
D. biotic potential
Chapter Review – STP4

83. Which model illustrates the amount of food energy available at each level of a community?
A. food chain
B. food web
C. matter cycle
D. energy pyramid
Chapter Review – STP5