1. End Show Slide 1 of 21 Copyright Pearson Prentice Hall Biology

2. End Show Slide 2 of 21 Copyright Pearson Prentice Hall 3-1 What Is Ecology?

3. End Show 3-1 What Is Ecology? Slide 3 of 21 Copyright Pearson Prentice Hall Interactions and Interdependence Ecology is the scientific study of interactions among organisms and between organisms and their environment, or surroundings.

4. End Show 3-1 What Is Ecology? Slide 4 of 21 Copyright Pearson Prentice Hall Interactions and Interdependence The biosphere contains the combined portions of the planet in which all of life exists, including: land water air, or atmosphere The biosphere extends from about 8 kilometers above Earth's surface to as far as 11 kilometers below the surface of the ocean.

5. End Show 3-1 What Is Ecology? Slide 5 of 21 Copyright Pearson Prentice Hall Interactions and Interdependence Interactions within the biosphere produce a web of interdependence between organisms and the environment in which they live. The interdependence of life on Earth contributes to an ever-changing, or dynamic, biosphere.

6. End Show 3-1 What Is Ecology? Slide 6 of 21 What different levels of organization do ecologists study? Copyright Pearson Prentice Hall Levels of Organization

7. End Show 3-1 What Is Ecology? Slide 7 of 21 Copyright Pearson Prentice Hall Levels of Organization To understand relationships within the biosphere, ecologists ask questions about events and organisms that range in complexity from a single individual to the entire biosphere. The levels of organization that ecologists study include: individuals, populations, communities, ecosystems, and biomes.

8. End Show 3-1 What Is Ecology? Slide 8 of 21 Copyright Pearson Prentice Hall Levels of Organization Ecosystem Community Population Individual Biome Biosphere

9. End Show 3-1 What Is Ecology? Slide 9 of 21 Copyright Pearson Prentice Hall Levels of Organization A species is a group of organisms so similar to one another that they can breed and produce fertile offspring. Populations are groups of individuals that belong to the same species and live in the same area. Communities are assemblages of different populations that live together in a defined area.

10. End Show 3-1 What Is Ecology? Slide 10 of 21 Copyright Pearson Prentice Hall Levels of Organization An ecosystem is a collection of all the organisms that live in a particular place, together with their nonliving, or physical, environment. A biome is a group of ecosystems that have the same climate and similar dominant communities. The highest level of organization that ecologists study is the entire biosphere itself.

11. End Show 3-1 What Is Ecology? Slide 11 of 21 Copyright Pearson Prentice Hall Ecological Methods What methods are used to study ecology?

12. End Show 3-1 What Is Ecology? Slide 12 of 21 Copyright Pearson Prentice Hall Ecological Methods Regardless of the tools they use, scientists conduct modern ecological research using three basic approaches: observing experimenting modeling All of these approaches rely on the application of scientific methods to guide ecological inquiry.

13. End Show 3-1 What Is Ecology? Slide 13 of 21 Copyright Pearson Prentice Hall Observing Observing is often the first step in asking ecological questions. Some observations are simple. Others are complex and may form the first step in designing experiments and models. Ecological Methods

14. End Show 3-1 What Is Ecology? Slide 14 of 21 Copyright Pearson Prentice Hall Ecological Methods Experimenting Experiments can be used to test hypotheses. An ecologist may set up an artificial environment in a laboratory to imitate and manipulate conditions that organisms would encounter in the wild. Other experiments are conducted within natural ecosystems.

15. End Show 3-1 What Is Ecology? Slide 15 of 21 Copyright Pearson Prentice Hall Ecological Methods Modeling Ecologists make models to gain insight into complex phenomena. Many ecological models consist of mathematical formulas based on data collected through observation and experimentation. The predictions made by ecological models are often tested by further observations and experiments.

16. End Show - or - Continue to: Click to Launch: Slide 16 of 21 Copyright Pearson Prentice Hall 3-1

17. End Show Slide 17 of 21 Copyright Pearson Prentice Hall 3-1 The combined portions of the planet in which life exists, including land, water, and the atmosphere, form the a.biosphere. b.community. c.species. d.ecosystem.

18. End Show Slide 18 of 21 Copyright Pearson Prentice Hall 3-1 A group of organisms that can breed and produce fertile offspring is known as a(an) a.ecosystem. b.species. c.biome. d.community.

19. End Show Slide 19 of 21 Copyright Pearson Prentice Hall 3-1 Compared to a community, an ecosystem includes a.the nonliving, physical environment as well as the community. b.only the physical environment of an area without the organisms. c.the entire biome but not the biosphere. d.only one of the populations within the community.

20. End Show Slide 20 of 21 Copyright Pearson Prentice Hall 3-1 An ecological method that uses mathematical formulas based on data collected is a.observing. b.experimenting. c.modeling. d.hypothesizing.

21. End Show Slide 21 of 21 Copyright Pearson Prentice Hall 3-1 An ecologist marks out an area in a specific ecosystem and proceeds to identify the number of insect species in the area. This is an example of ecological a.experimentation. b.observation. c.modeling. d.inference.

22. End Show Slide 22 of 21 Copyright Pearson Prentice Hall 3–2 Energy Flow

23. End Show Slide 23 of 21 Copyright Pearson Prentice Hall Producers Where does the energy for life processes come from?

24. End Show Slide 24 of 21 Copyright Pearson Prentice Hall Producers Without a constant input of energy, living systems cannot function. Sunlight is the main energy source for life on Earth.

25. End Show Slide 25 of 21 Copyright Pearson Prentice Hall Producers In a few ecosystems, some organisms obtain energy from a source other than sunlight. Some types of organisms rely on the energy stored in inorganic chemical compounds.

26. End Show Slide 26 of 21 Copyright Pearson Prentice Hall Producers Only plants, some algae, and certain bacteria can capture energy from sunlight or chemicals and use that energy to produce food. These organisms are called autotrophs. Because they make their own food, autotrophs are called producers.

27. End Show Slide 27 of 21 Copyright Pearson Prentice Hall Producers Energy From the Sun The best-known autotrophs harness solar energy through a process known as photosynthesis. During photosynthesis, these autotrophs use light energy to convert carbon dioxide and water into oxygen and energy-rich carbohydrates.

28. End Show Slide 28 of 21 Copyright Pearson Prentice Hall Producers Photosynthesis is responsible for adding oxygen to— and removing carbon dioxide from—Earth's atmosphere.

29. End Show Slide 29 of 21 Copyright Pearson Prentice Hall Producers Life Without Light Some autotrophs can produce food in the absence of light. When organisms use chemical energy to produce carbohydrates, the process is called chemosynthesis.

30. End Show Slide 30 of 21 Copyright Pearson Prentice Hall Producers

31. End Show Slide 31 of 21 Copyright Pearson Prentice Hall Consumers Many organisms cannot harness energy directly from the physical environment. Organisms that rely on other organisms for their energy and food supply are called heterotrophs. Heterotrophs are also called consumers.

32. End Show Slide 32 of 21 Copyright Pearson Prentice Hall Consumers There are many different types of heterotrophs. Herbivores eat plants. Carnivores eat animals. Omnivores eat both plants and animals. Detritivores feed on plant and animal remains and other dead matter. Decomposers, like bacteria and fungi, break down organic matter.

33. End Show Slide 33 of 21 Copyright Pearson Prentice Hall Feeding Relationships How does energy flow through living systems?

34. End Show Slide 34 of 21 Copyright Pearson Prentice Hall Feeding Relationships Energy flows through an ecosystem in one direction, from the sun or inorganic compounds to autotrophs (producers) and then to various heterotrophs (consumers).

35. End Show Slide 35 of 21 Copyright Pearson Prentice Hall Feeding Relationships Food Chains A food chain is a series of steps in which organisms transfer energy by eating and being eaten.

36. End Show Slide 36 of 21 Copyright Pearson Prentice Hall Feeding Relationships In some marine food chains, the producers are microscopic algae and the top carnivore is four steps removed from the producer. Algae Zooplankton Small Fish Squid Shark

37. End Show Slide 37 of 21 Copyright Pearson Prentice Hall Feeding Relationships Food Webs Ecologists describe a feeding relationship in an ecosystem that forms a network of complex interactions as a food web. A food web links all the food chains in an ecosystem together.

38. End Show Slide 38 of 21 Copyright Pearson Prentice Hall Feeding Relationships This food web shows some of the feeding relationshi ps in a salt-marsh community.

39. End Show Slide 39 of 21 Copyright Pearson Prentice Hall Feeding Relationships Trophic Levels Each step in a food chain or food web is called a trophic level. Producers make up the first trophic level. Consumers make up the second, third, or higher trophic levels. Each consumer depends on the trophic level below it for energy.

40. End Show Slide 40 of 21 Copyright Pearson Prentice Hall Ecological Pyramids How efficient is the transfer of energy among organisms in an ecosystem?

41. End Show Slide 41 of 21 Copyright Pearson Prentice Hall Ecological Pyramids Only about 10 percent of the energy available within one trophic level is transferred to organisms at the next trophic level.

42. End Show Slide 42 of 21 Copyright Pearson Prentice Hall Ecological Pyramids The amount of energy or matter in an ecosystem can be represented by an ecological pyramid. An ecological pyramid is a diagram that shows the relative amounts of energy or matter contained within each trophic level in a food chain or food web.

43. End Show Slide 43 of 21 Copyright Pearson Prentice Hall Ecological Pyramids Ecologists recognize three different types of ecological pyramids: energy pyramids biomass pyramids pyramids of numbers

44. End Show Slide 44 of 21 Copyright Pearson Prentice Hall Ecological Pyramids 0.1% Third-level consumers 1% Second-level consumers 10% First-level consumers 100% Producers Energy Pyramid: Shows the relative amount of energy available at each trophic level. Only part of the energy that is stored in one trophic level is passed on to the next level.

45. End Show Slide 45 of 21 Copyright Pearson Prentice Hall Ecological Pyramids 50 grams of human tissue 500 grams of chicken 5000 grams of grass Biomass Pyramid: Represents the amount of living organic matter at each trophic level. Typically, the greatest biomass is at the base of the pyramid.

46. End Show Slide 46 of 21 Copyright Pearson Prentice Hall Ecological Pyramids Pyramid of Numbers: Shows the relative number of individual organisms at each trophic level.

47. End Show Slide 47 of 21 Copyright Pearson Prentice Hall 3– 2

48. End Show Slide 48 of 21 Copyright Pearson Prentice Hall 3– 2 The main source of energy for life on Earth is organic chemical compounds. inorganic chemical compounds. sunlight. producers.

49. End Show Slide 49 of 21 Copyright Pearson Prentice Hall 3– 2 Organisms that feed on plant and animal remains and other dead matter are detritivores. carnivores. herbivores. autotrophs.

50. End Show Slide 50 of 21 Copyright Pearson Prentice Hall 3– 2 How does a food web differ from a food chain? A food web contains a single series of energy transfers. A food web links many food chains together. A food web has only one trophic level. A food web shows how energy passes from producer to consumer.

51. End Show Slide 51 of 21 Copyright Pearson Prentice Hall 3– 2 In a biomass pyramid, the base of the pyramid represents the mass of heterotrophs. primary consumers. producers. top level carnivores.

52. End Show Slide 52 of 21 Copyright Pearson Prentice Hall 3– 2 The amount of energy represented in each trophic level of consumers in an energy pyramid is about 10% of the level below it. 90% of the level below it. 10% more than the level below it. 90% more than the level below it.

53. End Show Slide 53 of 21 Copyright Pearson Prentice Hall 3–3 Cycles of Matter

54. End Show Slide 54 of 21 Copyright Pearson Prentice Hall 3-3 Cycles of Matter How does matter move among the living and nonliving parts of an ecosystem?

55. End Show Slide 55 of 21 Copyright Pearson Prentice Hall Recycling in the Biosphere Energy and matter move through the biosphere very differently. Unlike the one-way flow of energy, matter is recycled within and between ecosystems. Biogeochemical Cycles

56. End Show Slide 56 of 21 Copyright Pearson Prentice Hall The Water Cycle All living things require water to survive. The Water Cycle

57. End Show Slide 57 of 21 Copyright Pearson Prentice Hall The Water Cycle Water moves between the ocean, atmosphere, and land.

58. End Show Slide 58 of 21 Copyright Pearson Prentice Hall Nutrient Cycles How are nutrients important in living systems?

59. End Show Slide 59 of 21 Copyright Pearson Prentice Hall Nutrient Cycles All the chemical substances that an organism needs to sustain life are its nutrients. Every living organism needs nutrients to build tissues and carry out essential life functions. Similar to water, nutrients are passed between organisms and the environment through biogeochemical cycles.

60. End Show Slide 60 of 21 Copyright Pearson Prentice Hall Nutrient Cycles The Carbon Cycle Carbon is a key ingredient of living tissue. Biological processes, such as photosynthesis, respiration, and decomposition, take up and release carbon and oxygen. Geochemical processes, such as erosion and volcanic activity, release carbon dioxide to the atmosphere and oceans.

61. End Show Slide 61 of 21 Copyright Pearson Prentice Hall Nutrient Cycles CO 2 in Atmosphere Photosynthesis feeding Respiration Deposition Carbonate Rocks Deposition Decomposition Fossil fuel Volcanic activity Uplift Erosion Respiration Human activity CO 2 in Ocean Photosynthesis

62. End Show Slide 62 of 21 Copyright Pearson Prentice Hall Nutrient Cycles The Nitrogen Cycle All organisms require nitrogen to make proteins. Although nitrogen gas is the most abundant form of nitrogen on Earth, only certain types of bacteria can use this form directly. Such bacteria live in the soil and on the roots of plants called legumes. They convert nitrogen gas into ammonia in a process known as nitrogen fixation.

63. End Show Slide 63 of 21 Copyright Pearson Prentice Hall Nutrient Cycles Bacterial nitrogen fixation N 2 in Atmosphere NH 3 Synthetic fertilizer manufacturer Uptake by producers Reuse by consumers Decomposition excretion Atmospheric nitrogen fixation Uptake by producers Reuse by consumers Decomposition Decomposition excretion NO 3 and NO 2

64. End Show Slide 64 of 21 Copyright Pearson Prentice Hall Other soil bacteria convert nitrates into nitrogen gas in a process called denitrification. This process releases nitrogen into the atmosphere once again. Nutrient Cycles

65. End Show Slide 65 of 21 Copyright Pearson Prentice Hall Nutrient Cycles The Phosphorus Cycle Phosphorus is essential to organisms because it helps forms important molecules like DNA and RNA. Most phosphorus exists in the form of inorganic phosphate. Inorganic phosphate is released into the soil and water as sediments wear down.

66. End Show Slide 66 of 21 Copyright Pearson Prentice Hall Organic phosphate moves through the food web and to the rest of the ecosystem. Nutrient Cycles Ocean Land Organisms Sediments

67. End Show Slide 67 of 21 Copyright Pearson Prentice Hall Nutrient Limitation The primary productivity of an ecosystem is the rate at which organic matter is created by producers. One factor that controls the primary productivity of an ecosystem is the amount of available nutrients.

68. End Show Slide 68 of 21 Copyright Pearson Prentice Hall If a nutrient is in short supply, it will limit an organism's growth. When an ecosystem is limited by a single nutrient that is scarce or cycles very slowly, this substance is called a limiting nutrient. Nutrient Limitation

69. End Show Slide 69 of 21 Copyright Pearson Prentice Hall When an aquatic ecosystem receives a large input of a limiting nutrient—such as runoff from heavily fertilized fields—the result is often an immediate increase in the amount of algae and other producers. This result is called an algal bloom. Algal blooms can disrupt the equilibrium of an ecosystem. Nutrient Limitation

70. End Show Slide 70 of 21 Copyright Pearson Prentice Hall 3– 3

71. End Show Slide 71 of 21 Copyright Pearson Prentice Hall 3– 3 Transpiration is part of the water cycle. carbon cycle. nitrogen cycle. phosphorus cycle.

72. End Show Slide 72 of 21 Copyright Pearson Prentice Hall 3– 3 Carbon is found in the atmosphere in the form of carbohydrates. carbon dioxide. calcium carbonate. ammonia.

73. End Show Slide 73 of 21 Copyright Pearson Prentice Hall 3– 3 Biologists describe nutrients as moving through cycles because the substances start as simple organic forms that plants need. provide “building blocks” and energy that organisms need. are passed between organisms and the environment and then back to organisms. are needed by organisms to carry out life processes.

74. End Show Slide 74 of 21 Copyright Pearson Prentice Hall 3– 3 The only organisms that can convert nitrogen in the atmosphere into a form useful to living things are nitrogen-fixing plants. bacteria. detritivores. animals.

75. End Show Slide 75 of 21 Copyright Pearson Prentice Hall 3– 3 When an aquatic ecosystem receives a large input of a limiting nutrient, the result is runoff. algal death. algal bloom. less primary productivity.