Name ______________________________ Class__________________ Date __________________

Skills Worksheet

Active Reading Section 1: Energy Flow in Ecosystems Read the passage below and answer the questions that follow.

Energy from the sun enters an ecosystem when a plant uses sunlight to make sugar molecules by a process called photosynthesis. During photosynthesis, plants, algae, and some bacteria capture solar energy. Solar energy drives a series of chemical reactions that require carbon dioxide and water. The result of photosynthesis is the production of sugar molecules known as carbohydrates. Carbohydrates are energy-rich molecules which organisms use to carry out daily activities. As organisms consume other plants or animals, energy is transferred from one organism to another. Plants produce carbohydrates in their leaves. When an animal eats a plant, some energy is transferred from the plant to the animal. Organisms use this energy to move, grow, and reproduce. IDENTIFYING MAIN IDEAS

One reading skill is the ability to identify the main idea of a passage. The main idea is the main focus or key idea. Frequently a main idea is accompanied by supporting information that offers detailed facts about main ideas. In the space provided, write the letter of the term or phrase that best completes each statement or best answers each question.

_____ 1. Plants, algae, and some bacteria capture ______________________during photosynthesis. a. solar energy c. carbon dioxide b. carbohydrates d. organisms _____ 2. The chemical reactions driven by solar energy require a. carbon dioxide and water. c. organisms and water. b. plants and algae. d. carbon dioxide and sugar molecules. _____ 3. During photosynthesis, plants make a. carbohydrates. c. water. b. carbon dioxide. d. None of the above _____ 4. Where does the production of carbohydrates in a plant take place? a. in the carbohydrates c. in the ecosystem b. in the leaves d. in the stems

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How Ecosystems Work

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Active Reading continued VOCABULARY DEVELOPMENT Read each question and write the answer in the space provided.

5. Energy-rich molecules that organisms use to carry out daily activities are. ______________________ 6. The process by which a plant uses sunlight to make sugar molecules is called ______________________ SEQUENCING INFORMATION

One reading skill is the ability to sequence information, or to logically place items or events in the order in which they occur. Sequence the statements below to show the steps in the process of energy production and consumption. Write “1” on the line in front of the first step, “2” on the line in front of the second step, and so on.

_____ 7. Photosynthesis produces carbohydrates. _____ 8. Plants, algae, and some bacteria capture solar energy. _____ 9. Energy is transferred from one organism to another. _____ 10. Solar energy drives a series of chemical reactions. _____ 11. Other organisms consume carbohydrates found in plants, algae, and some bacteria. RECOGNIZING CAUSE AND EFFECT

One reading skill is the ability to recognize cause and effect. In the space provided, write the letter of the effect that best matches the cause.

a. Carbohydrates are produced. b. Energy is transferred from one organism to another. c. Energy from the plant is transferred and used to move, grow, and reproduce.

_____ 12. Organisms consume food and use energy from carbohydrates. _____ 13. A plant uses sunlight for photosynthesis. _____ 14. An animal eats a plant.

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How Ecosystems Work

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Skills Worksheet

Critical Thinking ANALOGIES Mark the letter of the pair of terms that best completes the analogy shown. An analogy is a relationship between two pairs of words or phrases written as a : b :: c : d. The symbol : is read “is to,” and the symbol :: is read “as.” ______ 1. producer : consumer ::

a. b. c. d.

car : driver factory : shopper deer : wolf photosynthesis : decomposition

______ 2. herbivores : omnivores ::

a. b. c. d.

photosynthesis : respiration elephant : ocean fruit : bird deer : bear

______ 3. carbon dioxide : carbon cycle ::

a. b. c. d.

fertilizer : phosphorus cycle atmospheric nitrogen : nitrogen cycle decomposers : carbon cycle limestone : carbon cycle

______ 4. deep ocean : hydrogen sulfide ::

a. b. c. d.

sunlight : deep ocean darkness : sunlight surface : carbon dioxide photosynthesis : sunlight

______ 5. oxygen : cellular respiration ::

a. b. c. d.

cup : saucer carbon dioxide : photosynthesis plants : adaptation needle : thread

______ 6. climax forest : clear-cut forest ::

a. b. c. d.

plants : animals food web : food chain sun : fire full : empty

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How Ecosystems Work

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Critical Thinking continued INTERPRETING OBSERVATIONS Read the following passage, and then answer the questions below.

Your family is considering buying a house near a nature preserve that has been established to maintain a portion of the original ecosystem. You attend a meeting in which the developer is explaining the plans for the project. One woman in the audience complains that she does not like the natural prairie grasses on the nature preserve. She wants the grasses removed and replanted with an imported grass. A man in the audience suggests that exotic animals on the preserve would make it more beautiful. One woman proposes that the developer construct a playground in the center of the preserve and build a paved road to it. She wants picnic tables set up throughout the preserve for family picnics. 7. What would be your response to the woman who wants to replace the native grasses? ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________

8. What would be your response to the man who wants exotic animals placed on the site? ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________

9. What would be your response to the woman who wants to put a playground on the site? ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________

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How Ecosystems Work

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Critical Thinking continued AGREE OR DISAGREE Agree or disagree with the following statements, and support your answer.

10. There would be no life on Earth without the sun. ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________

11. Our activities do not affect the carbon cycle. ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________

12. A severe drought in a grassland will reduce the number of consumers in the entire energy pyramid. ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________

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How Ecosystems Work

Name ______________________________ Class___________________ Date __________________

Critical Thinking continued REFINING CONCEPTS The statements below challenge you to refine your understanding of concepts covered in the chapter. Think carefully, and answer the questions that follow.

13. Explain why the difference between primary and secondary succession is not always clear. ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________

14. Explain what you think would happen to the phosphorus, carbon, and nitrogen cycles if the sun were to burn out. ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________

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How Ecosystems Work

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Critical Thinking continued

15. Energy pyramids are useful for describing the energy losses in a food chain. Describe an energy pyramid for a group of organisms in your area. ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________

16. Explain the importance of lichens to primary succession. ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________

17. Explain how a clover is part of the carbon, nitrogen, and phosphorus cycles. ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________

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Holt McDougal Environmental Science

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How Ecosystems Work

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Skills Worksheet

GLOBAL WARMING

Map Skills

FO Global warming is a rise in the average temperature of Earth’s atmosphere over a long period of time. It is caused by the release of gases, especially carbon dioxide. Harmful levels of carbon dioxide are emitted into the air by car exhaust, power plants, and other human activities. This map shows which regions of Earth contribute most to global warming. Use the map above to answer the questions below.

1. Using a Key Are developed regions or developing regions responsible for the highest percentage of carbon dioxide output from fossil fuels? _______________________________________________________________ 2. Finding Locations Which region has the highest percentage of carbon dioxide output? the lowest? _______________________________________________________________ 3. Making Conclusions Why do you think developed regions have a higher output of carbon dioxide? _______________________________________________________________ _______________________________________________________________ 4. Making a Hypothesis What might explain the fact that although Australia is developed, it has the lowest percentage of carbon dioxide output? _______________________________________________________________ © Houghton Mifflin Harcourt Publishing Company

Holt McDougal Environmental Science

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How Ecosystems Work

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Skills Worksheet

Study Guide MATCHING In the space provided, write the letter of the term or phrase that best matches the description.

_____ 1. two types of consumers _____ 2. a diagram showing the many feeding relationships that are in an ecosystem _____ 3. the process in which energy from the sun is used by plants to make sugar molecules _____ 4. illustrates the loss of energy from one trophic level to the next _____ 5. organisms that get their energy by eating other organisms

a. b. c. d. e. f. g. h. i. j. k. l.

photosynthesis rabbit and coyote fossil fuels producers food web consumers atmospheric CO2 energy pyramid algal bloom atmospheric N2 food chain old-field succession m. nitrogen-fixing bacteria

_____ 6. stored carbon from the remains of plants and animals that died millions of years ago _____ 7. organisms that make their own food _____ 8. change that occurs on an abandoned farm _____ 9. a part of the carbon cycle _____ 10. results from excessive use of fertilizers

_____ 11. organisms that transform atmosphereic nitrogen into usable nitrogen compounds _____ 12. part of the nitrogen cycle _____ 13. transfer of energy from one organism to another

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Holt McDougal Environmental Science

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How Ecosystems Work

Name ______________________________ Class___________________ Date __________________

Study Guide continued MULTIPLE CHOICE In the space provided, write the letter of the term or phrase that best completes each statement or best answers each question.

_____ 14. What are the first organisms to colonize any newly available area called? a. climax species b. ferns c. pioneer species d. mosses

_____ 19. Which of the following is an herbivore? a. cow b. lion c. bear d. grass _____ 20. Which of the following is a producer? a. oak tree b. raccoon c. cockroach d. human

_____ 15. Which of the following is a producer that breaks down rock? a. pioneer producer b. fungal species c. algae d. lichen

_____ 21. Which of the following is a process in the cell where by glucose and oxygen produce carbon dioxide, water, and energy? a. photosynthesis b. cellular respiration c. synthesis d. decomposition

_____ 16. Humans are affecting the balance of the carbon cycle by a. burning fossil fuels. b. using carbonates at an alarming rate. c. using fertilizers. d. replanting the rain forests.

_____ 22. Which of the following organisms would be found at the top of an energy pyramid? a. alga b. krill c. leopard seal d. killer whale

_____ 17. What is a pattern of change that occurs on a surface where an ecosystem has previously existed? a. primary succession b. secondary succession c. tertiary succession d. climax community

_____ 23. Humans usually get the phosphorus that their bodies need from a. eating plants and animals that contain phosphorus. b. mining. c. food additives. d. drinking water.

_____ 18. What do deep-ocean bacteria use to make their food? a. the sun b. hydrogen sulfide c. carbon dioxide d. sugar molecules

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How Ecosystems Work

Nombre

Clase

Fecha

Hoja de destrezas

Guía de estudio RELACIONAR En el espacio en blanco, escribe la letra de la palabra o frase que corresponda mejor con la descripción.

a. fotosíntesis

______ 1. dos tipos de consumidores ______ 2. diagrama que muestra las múltiples relaciones alimenticias que existen en un ecosistema

b. conejo y coyote c. combustibles fósiles d. productores

______ 3. proceso en el cual las plantas usan la energía del Sol para fabricar moléculas de azúcar

e. red alimenticia

______ 4. ilustra la pérdida de energía de un nivel trófico al siguiente

h. pirámide de energía

______ 5. organismos que obtienen su energía al comerse otros organismos ______ 6. carbono almacenado a partir de los restos de plantas y animales que murieron hace millones de años ______ 7. organismos que producen su propio alimento

f. consumidores g. CO2 atmosférico i. proliferación desmedida de algas j. N2 atmosférico k. cadena alimenticia l. sucesión en terreno anterior m. bacterias fijadoras de nitrógeno

______ 8. cambio que ocurre en una granja abandonada ______ 9. parte del ciclo del carbono ______ 10. se produce por el uso excesivo de fertilizantes ______ 11. organismos que transforman el nitrógeno atmosférico en compuestos utilizables de nitrógeno ______ 12. parte del ciclo del nitrógeno ______ 13. transferencia de energía de un organismo a otro

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Cómo funcionan los ecosistemas

Nombre

*XtDGHHVWXGLR

Clase

Fecha

(continuación)

OPCIÓN MÚLTIPLE En el espacio en blanco, escribe la letra de la palabra o frase que complete mejor la oración o que sea la mejor respuesta a la pregunta.

______ 14. ¿Cómo se llaman los primeros organismos que colonizan un área recientemente disponible? a. especie clímax b. helechos c. especie pionera d. musgos

______ 19. ¿Cuál de los siguientes es un herbívoro? a. la vaca b. el león c. el oso d. el pasto

______15. ¿Cuál de estos es un productor degradador de roca? a. productor pionero b. especie de hongo c. alga d. liquen

______ 16. Los seres humanos afectan el equilibrio del ciclo del carbono al a. quemar combustibles fósiles. b. usar carbonatos a una tasa alarmante. c. usar fertilizantes. d. replantar los bosques tropicales.  ______ 17. Un tipo común de sucesión que ocurre en una superficie donde anteriormente hubo un ecosistema es una a. sucesión primaria b. sucesión secundaria c. sucesión terciaria d. comunidad clímax

______20. ¿Cuál de los siguientes es un productor? a. el roble b. el mapache c. la cucaracha d. el ser humano ______21. ¿Cuál de los siguientes es un proceso de la célula en el que la glucosa y el oxígeno producen dióxido de carbono, agua y energía? a. la fotosíntesis b. la respiración celular c. la síntesis d. la descomposición ______22. ¿Cuál de los siguientes organismos se encontraría en la punta de la pirámide de energía? a. el alga b. el krill antártico c. el leopardo de mar d. la orca ______23. Los seres humanos generalmente obtienen el fósforo que necesitan a partir de a. la ingestión de plantas y animales que contienen fósforo. b. la minería. c. los aditivos alimenticios. d. el agua potable.

______ 18. ¿Qué usan las bacterias de las profundidades del océano para producir su alimento? a. el Sol b. el sulfuro de hidrógeno c. el dióxido de carbono d. las moléculas de azúcar © Houghton Mifflin Harcourt Publishing Company Holt McDougal Environmental Science

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Cómo funcionan los ecosistemas