Matter and Energy in Ecosystems

Content Vocabulary LESSON 3 Matter and Energy in Ecosystems Directions: Complete the triangles below. In the bottom left section, write a definition for the term; include the word transfer in at least one of the definitions. In the bottom right section, draw a picture to illustrate the term. For the food chain and food web illustrations, include diagrams with arrows. consumer 1. 2. producer 3. 4. food chain 5. 6. food web 7. 8. 46 Interactions of Life

Lesson Outline LESSON 3 Matter and Energy in Ecosystems A. Matter and Energy 1. Most of the on Earth today has been here since our planet formed. 2. Matter can neither be created nor, but it can change. 3. As organisms grow, die, and, matter cycles through. 4. cannot be recycled, but it can change from one form to another, as when the to and thermal energy. energy in burning wood changes B. Obtaining Energy 1. Every organism needs a constant supply of to stay alive. 2. The energy that is used by most organisms on Earth comes from the. a. Using the process of, some organisms use light energy, produce., and carbon dioxide to b. Organisms that use an outside energy source such as the Sun to produce their own food are called. c. The in food is stored in the bonds that hold the molecules in the food together. d. When these bonds break during the process of, is released. 3. Organisms that cannot make their own food are called ; there are four main kinds of consumers. a. are consumers that eat plants and other kinds of producers; some examples are snails, deer, rabbits, and bees. b. are consumers that eat herbivores and other types of consumers; some examples are cats, snakes, hawks, frogs, and spider. Interactions of Life 47

Lesson Outline continued c. are consumers that eat both producers and other consumers; some examples are bears, robins, pigs, rats, and humans. d. are consumers that break down the bodies of dead organisms; some examples are fungi, bacteria, wood lice, termites, and earthworms. e. Decomposers help matter. C. Transferring Energy 1. Energy can be from one organism to another in ecosystems when one organism another organism. 2. A(n) is a model that shows how energy flows in an ecosystem through feeding relationships. a. A food chain always begins with a(n) because they are the source of community. for all other organisms in a b. Energy moves in a food chain from producer to or omnivore and then to other omnivores and carnivores, and finally to. c. The in a food chain show the direction of the energy transfer. 3. A model of energy transfer that can show how the food chains in a community are interconnected is called a(n). 48 Interactions of Life

Content Practice A LESSON 3 Matter and Energy in Ecosystems Directions: Circle the term or phrase in parentheses that correctly completes each sentence. 1. Matter can (change form/be created). 2. Some matter (disappears/cycles) through ecosystems as organisms grow, die, and decompose. 3. Energy can be converted and (recycled/transferred). 4. (Photosynthesis/Cellular respiration) is the process during which some organisms produce their own food. 5. (Nitrogen/Carbon dioxide) is used during photosynthesis, along with water and light energy. 6. Organisms that use photosynthesis are called (producers/consumers). 7. (Photosynthesis/Cellular respiration) is the process that breaks the chemical bonds that hold food molecules together. 8. (Consumers/Producers) are organisms that cannot make their own food. 9. People eat plants and animals, so they are classified as (omnivores/carnivores). 10. Food chains and food webs are models used to show how (matter/energy) is transferred. 11. A food chain always begins with a (decomposer/producer). 12. To show all the interconnected feeding relationships in an ecosystem, you would use a food (chain/web). 50 Interactions of Life

Content Practice B LESSON 3 Matter and Energy in Ecosystems Directions: Answer each question or respond to each statement in the space provided. Question Answer 1. Describe how matter moves through ecosystems. 2. Describe how energy moves through ecosystems. 3. How do producers get the energy they need to maintain life? 4. How do consumers get the energy they need to maintain life? 5. Compare an herbivore and a carnivore. 6. Compare a carnivore and an omnivore. 7. What role do decomposers have in ecosystems? 8. Compare a food chain and a food web. Interactions of Life 51

Key Concept Builder LESSON 3 Matter and Energy in Ecosystems Key Concept How do matter and energy move through ecosystems? Directions: On each line, write the term from the word bank that correctly completes each sentence. Each term is used only once. chemical energy converted created cycles destroyed energy form matter thermal energy Almost all the (1.) planet formed. Matter can change (2.) on Earth today has been here since the, but it cannot be (3.) or (4.). Some matter (5.) through ecosystems as organisms grow, die, and decompose. Unlike matter, (6.) cannot be recycled. However, it can be (7.). For example, the (8.) in a log converts to light energy and (9.) Directions: Draw how matter moves through ecosystems in the space provided. when the log burns. Interactions of Life 55

Key Concept Builder LESSON 3 Matter and Energy in Ecosystems Key Concept How do organisms obtain energy? Directions: Complete the chart with the correct terms from the word bank in the space provided. Each term is used only once. carnivore decomposer herbivore omnivore Types of Consumers 1. Eats only plants and other producers. 2. Eats herbivores and other consumers. 3. Eats producers and consumers. 4. Breaks down dead organisms. Directions: Answer each question on the lines provided. 5. Where does most energy on Earth come from? 6. What is a producer? 7. What happens during photosynthesis? 8. What happens during cellular respiration? 56 Interactions of Life

Key Concept Builder LESSON 3 Matter and Energy in Ecosystems Key Concept What are the differences between a food chain and a food web? Directions: On each line, write the term from the word bank that correctly completes each sentence. Each term is used only once. ecosystems energy energy transfer food chain food web interconnected models omnivore predator prey producer transferred 1. Energy can be from one organism to another. 2. Food chains and food webs are used to describe energy transfers. 3. A model that shows how energy flows in an ecosystem through feeding relationships is a(n). 4. A food chain always begins with a(n) because these organisms are the source of energy for the other organisms in a community. 5. In a food chain, moves from producer to herbivore or, and then on to other consumers. 6. In a food chain, arrows show the directions of. 7. Most contain many food chains. 8. A(n) is a more complex model of energy transfer that can show how the food chains in a community are. 9. In a typical food web, an arrow points from a(n) such as a mouse to a(n) such as a cat. Interactions of Life 57

Key Concept Builder LESSON 3 Matter and Energy in Ecosystems Key Concept What are the differences between a food chain and a food web? Directions: Use the diagram to answer each question on the lines provided. Hawk Berries Pigeon Butterfly Insects Grass Mouse Cat 1. Which organisms in the food web are producers? 2. Which organism is an omnivore? How do you know? 3. Which organisms would be affected if the producers disappeared? Explain. 58 Interactions of Life

Name Date Class Ecosystems and Biomes Section Summary Energy Flow in Ecosystems Guide for Reading What energy roles do organisms play in an ecosystem? How does energy move through an ecosystem? How much energy is available at each level of an energy pyramid? An organism s energy role is determined by how it obtains energy and how it interacts with the other living things in its ecosystem. Each of the organisms in an ecosystem fills the energy role of producer, consumer, or decomposer. Plants, algae, and some bacteria can carry out photosynthesis. In this process, the organism uses the sun s energy to turn water and carbon dioxide into sugar molecules. An organism that can make its own food is a producer. Producers are the source of all the food in an ecosystem. Other organisms cannot make their own food. They depend on producers for food and energy. An organism that obtains energy by feeding on other organisms is a consumer. Consumers are classified by what they eat. Consumers that eat only plants are called herbivores. Consumers that eat only animals are called carnivores. A consumer that eats both plants and animals is called an omnivore. A scavenger is a carnivore that feeds on the bodies of dead organisms. An organism may play more than one role in an ecosystem. Organisms that break down wastes and dead organisms and return the raw materials to the environment are called decomposers. As decomposers obtain energy for their own needs, they return simple molecules to the environment to be used again by other organisms. The movement of energy through an ecosystem can be shown in diagrams called food chains and food webs. A food chain is a series of events in which one organism eats another and obtains energy. The first organism in a food chain is always a producer. The second organism, called a first-level consumer, eats the producer. The next consumer, called a secondlevel consumer, eats the first-level consumer. A food chain shows just one possible path of energy through an ecosystem. Most producers and consumers are part of many food chains. A more realistic way to show the flow of energy through an ecosystem is a food web. A food web consists of the many overlapping food chains in an ecosystem. When an organism makes its own food or eats other organisms, it obtains energy. The organism uses most of this energy for its own life processes. Only some of the energy will be available to the next organism in the food web. A diagram called an energy pyramid shows the amount of energy that moves from one feeding level to another in a food web. The most energy is available at the producer level of the pyramid. As you move up the pyramid, each level has less available energy than at the level below. In general, only about 10 percent of the energy at one level of a food web is transferred to the next higher level. For this reason, most food webs have only three or four feeding levels, with few organisms at the highest level in a food web. Pearson Education, Inc., publishing as Pearson Prentice Hall. All rights reserved.

Name Date Class Ecosystems and Biomes Review and Reinforce Energy Flow in Ecosystems Understanding Main Ideas Answer the following questions on a separate sheet of paper. Hawk Coyote Mouse Rabbit Grasshopper Grass Alfalfa 1. Which organism in the food web above is sometimes a first-level consumer and sometimes a second-level consumer? Explain. 2. Choose one food chain in the web. Name all the organisms in that chain. Start with the producer and end with the top-level consumer. 3. Draw an energy pyramid for the food chain you chose. Label the pyramid to tell how much food energy is available at each level. Building Vocabulary On a separate sheet of paper, write the term that fits each definition below. 4. Organisms that make their own food 5. Organisms that obtain energy by feeding on other organisms 6. Organisms that break down wastes and dead organisms and return the raw materials to the environment 7. Consumers that eat only animals 8. Consumers that eat only plants 9. Consumers that eat both plants and animals 10. Consumers that feed on the bodies of dead organisms Pearson Education, Inc., publishing as Pearson Prentice Hall. All rights reserved.

Ecosystems and Biomes Name Date Class Ecosystems and Biomes Enrich Food Webs at Hydrothermal Vents Deep below the ocean s surface are strange ecosystems called hydrothermal vents. Here, heated water rises up through cracks in the ocean floor. The water contains minerals from Earth s interior. No sunlight ever reaches these vents. No plants or algae live there. The table below lists the organisms found at hydrothermal vents. Life at a Hydrothermal Vent Organisms Shrimp Crabs Giant clams Bacteria Giant tube worms Obtain food energy from... Bacteria in the water Remains of other organisms Bacteria in the water Make their own food from chemicals in the water Bacteria living inside their bodies Use the information in the table to respond to the following items. 1. Which organisms are the producers at hydrothermal vents? 2. Which organisms are first-level consumers? 3. What type of consumer are the crabs? 4. In the space below, draw the food web at a hydrothermal vent. Label each organism to identify its energy role in the ecosystem. Pearson Education, Inc., publishing as Pearson Prentice Hall. All rights reserved.

Third-Level Consumers (1 kcal) Second-Level Consumers (10 kcal) First-Level Consumers (100 kcal) Producers (1,000 kcal)

Quick Vocabulary Lesson 1 Lesson 2 abiotic factor nonliving part of an ecosystem atmosphere the whole mass of air surrounding Earth biotic factor living or once-living things in an ecosystem community all the populations living in the same area at the same time ecosystem all the living things and nonliving things in a given area habitat place within an ecosystem that provides food, water, shelter, and other biotic and abiotic factors an organism needs to survive and reproduce population all the organisms of the same species that live in the same area at the same time population density size of a population compared to the amount of space available commensalism symbiotic relationship in which one organism benefits but the other neither benefits nor is harmed competition demand for resources, such as food, water, and shelter, in short supply in a community mutualism symbiotic relationship in which both organisms benefit niche way a species interacts with abiotic and biotic factors to obtain food, find shelter, and fulfill other needs overpopulation when a population becomes so large that it causes damage to the environment parasitism symbiotic relationship in which one organism benefits while the other is harmed predation act of one organism, a predator, feeding on another organism, its prey symbiosis close, long-term relationship between two species that usually involves an exchange of food or energy Interactions of Life 3

Quick Vocabulary Lesson 3 consumer organism that cannot make its own food; obtains food by eating producers or other consumers food chain model that shows how energy flows in an ecosystem through feeding relationships food web model of energy transfer that can show how the food chains in a community are interconnected producer organism that uses an outside energy source, such as the Sun, and produces its own food transfer to pass from one to another 4 Interactions of Life

Lesson Quiz A LESSON 3 Matter and Energy in Ecosystems True or False Directions: On the line before each or statement, write T if the statement is true or F if the statement is false. If the statement is false, change the underlined word(s) to make it true. Write your changes on the lines provided. 1. Energy can be recycled through ecosystems as organisms grow, die, and decompose. 2. Most of the energy used by organisms on Earth comes from the Sun. 3. A food chain is a model that shows how matter flows through an ecosystem. Matching Directions: On the line before each definition, write the letter of the term that matches it correctly. Each term is used only once. 4. eats producers and consumers 5. eats only producers 6. makes its own food 7. eats dead organisms 8. eats consumers but not producers A. carnivore B. decomposer C. herbivore D. omnivore E. producer Interactions of Life 61