Skills Worksheet Active Reading

Name

Class

Date

Skills Worksheet

Active Reading

Section: 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 food and use

energy from carbohydrates, the energy travels 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.

c. carbon dioxide

a. solar energy

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

Name

Class

Date

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.

______12. Organisms consume food

and use energy from

carbohydrates.

a. Carbohydrates are produced.

b. Energy travels from one organism

to another.

c. Energy from the plant is transferred and used to move, grow,

and reproduce.

______13. A plant uses sunlight for

photosynthesis.

______14. An animal eats a plant.

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How Ecosystems Work

TEACHER RESOURCE PAGE

14.

15.

16.

17.

Active Reading

Surfaces left biologically barren (by

events, such as a very intense fire) may

appear to be ¡°previously unoccupied¡±;

however, the plants which grow in such

places are correctly referred to as

¡°secondary succession.¡±

The phosphorus cycle would eventually stop. Without the sun, plants

would die, depriving the consumers

of their source of food and phosphorus. Without plants to eat, consumers

would starve. The carbon cycle would

also stop because it is driven by photosynthesis, which could not take

place without sunlight. The nitrogen

cycle would probably stop as well.

Although some nitrogen could continue to move between the soil and

the atmosphere without the help of

plants (i.e., through processing by

bacteria), the ground would eventually freeze without the heat from the

sun, and the bacteria would presumably freeze as well.

Answers may vary. Sample answer:

Leaf lettuce uses photosynthesis to

produce its energy. The lettuce is at

the bottom of the energy pyramid

and is the producer. A grasshopper

eats the leaf lettuce. The grasshopper

is a primary consumer. A bird eats

the grasshopper. The bird is the secondary consumer. A house cat eats

the bird. The cat is the tertiary

consumer.

Lichens break up the rock and begin

the process of turning it into soil that

can support plant life.

Clover is part of the carbon cycle

because it uses photosynthesis to

convert carbon dioxide into carbohydrates. It is part of the nitrogen cycle

because it is a legume, which has

nitrogen-fixing bacteria in the nodules on the roots of the plant. This

bacteria converts atmospheric nitrogen into nitrogen compounds that are

useful for other organisms. Clover is

part of the phosphorus cycle because

it gets the phosphorus that it needs

from the soil. Organisms that eat this

clover will get the phosphorus they

need from the plant.

SECTION: ENERGY FLOW IN

ECOSYSTEMS

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

11.

12.

13.

14.

a

a

a

b

carbohydrates

photosynthesis

3

1

5

2

4

b

a

c

SECTION: THE CYCLING OF

MATERIALS

1.

2.

3.

4.

5.

6.

7.

8.

9.

fossil fuels

carbon dioxide

vehicles

six billion metric tons

Answers may vary. The author wants

to point out how much fuel people in

the United States use and how much

carbon dioxide is emitted because of

it. Most people reading this textbook

are from the United States, so the

author knows this example will be

most relevant.

b

c

burning of fossil fuels, natural burning

of wood, and forest fires

They may contribute to global warming.

SECTION: HOW ECOSYSTEMS CHANGE

1. secondary succession

2. Answers may vary. Pioneer species

grow rapidly, then taller plants grow

and the pioneer species die. Finally,

trees grow and deprive the taller

plants of light and water. Eventually, a

climax community develops.

3. Accept reasonable responses, which

may include secondary succession, climax community, and pioneer species.

4. secondary succession: the sequence

of plant growth that occurs when an

area of land is allowed to return to its

natural state; climax community: the

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How Ecosystems Work

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