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PageLife Science .................................................................................... 2

Discovery on the Galapagos Islands...........................................6A Real Cool Bird: The Penguin ...................................................8Does the Loch Ness Monster Exist? .........................................10Eyes That Migrate......................................................................12Salt Marshes...............................................................................14Getting the Facts About Bears ..................................................16Squirrels and Walnuts ...............................................................18Tent Caterpillars and Fall Webworms ......................................20The Tree Killer ...........................................................................22Watch Your Diet!........................................................................24The Language of the Laughing Gulls .......................................26An Ideal Environment for Raptors ...........................................28A Strange Fish with a Long History .........................................30Pink Warning from a Flower ....................................................32The Powerful Tools in Your Mouth ..........................................34Understanding the Language of a Dog.....................................36Colors That Shout “Beware!” ....................................................38Immunization ............................................................................40A Healthy Body ..........................................................................42The Gift of Sight ........................................................................44

Earth-Space Science................................................................... 46Dima, the Baby Mammoth........................................................50Warm-Blooded Dinosaurs? .......................................................52The Peru Current .......................................................................54Jupiter Hit! .................................................................................56Bones in the La Brea Tar Pits ...................................................58The Cold World of Glaciers.......................................................60Fire Inside the Earth .................................................................62Quiet Zones and Earthquakes...................................................64The Most Violent Storm On Earth ...........................................66The Language of Hurricane Forecasting..................................68Building in Space.......................................................................70

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CONTENTS

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Page A Blast from the Sun .................................................................72Asteroids .....................................................................................74Strange Weather.........................................................................76

Physical Science.......................................................................... 78Marking Time.............................................................................82Underwater Echoes....................................................................84Hunting by Sound .....................................................................86A Different Kind of Train ..........................................................88Global Positioning System ........................................................90Smaller Than an Atom ..............................................................92Space-Age Dentists.....................................................................94 Lighter-Than-Air Airships.....................................................96How Light Affects Humans ..................................................98Bernie Makes Power ............................................................100Two Unlikely Treasures .......................................................102Silence Is Golden..................................................................104

Environmental Science.............................................................. 106Saving the Cheetah ..............................................................110Trash: What Good Is It? ......................................................112Solar Energy Can Put You Into Hot Water! ...................114Know Your Lead ...................................................................116Danger Beneath the Earth..................................................118Electric Vehicles Are Back .................................................120New Visitors to Zoo Atlanta...............................................122Yosemite National Park ......................................................124The Vanishing Forests .........................................................126Too Hot, Too Wet, Too Dry.................................................128

Record Keeping ......................................................................... 130

Metric Tables............................................................................... 132

Bibliography............................................................................... 134

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Discovery on the Galapagos Islands

6 LIFE SCIENCE

Charles Darwin,a famous scien-tist, thought so.Darwin made animportant discov-ery in 1835, while

vis i t ing the Galapagos Islands inthe Pacific Ocean. He found evidencefor a theory (the re), or set of ideas, hehad about how living things slowlychange to adapt to their environments.Darwin found two interesting crea-tures on the islands: a finch, which isa kind of bird, and a tortoise, or turtle.

Altogether, Darwin found 14 kindsof finches. Each kind differed fromthe other only in the size and the shapeof its beak. Darwin theorized that,over thousands of years, the fincheshad adapted so that each kind couldeat a certain type of food. For exam-ple, a large, heavy beak is good forcracking seeds, and a narrow, thinbeak is good for finding insects in rot-ten wood.

Darwin found more evidence forhis theory when he discovered gianttortoises on several islands. He

observed that the tortoises wereslightly different from their rela-tives on neighboring islands. Onislands with thick vegetation, thetortoises had thick, short necks.Food is easy to reach on theseislands. On desert-like islands,tortoises had long necks to helpthem reach high into the bushesfor food. Only the tortoises andfinches that survived could haveyoung that eventually becamelike their parents. They, too,were able to survive and adapt totheir homes on the GalapagosIslands.

Do livingthings adaptto theirenvironments?

__

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LIFE SCIENCE 7

1. The word in the story that means “a set of ideas” is __________.

2. While on the Galapagos Islands, Darwin found that living things

a. adapt quickly to their environments.

b. change slowly to live in their environments.

c. never change over thousands of years.

3. Each of the Darwin finches was alike except for its __________.

4. The finches’ beaks were useful for

a. eating different foods.

b. hiding their young.

c. smelling their enemies.

5. Darwin found that tortoises with short necks

a. have difficulty finding insects in wood.

b. eat vegetation that grows close to the ground.

c. live on islands that are like deserts.

6. Which of the following is true according to Darwin’s theory?

a. Young animals are stronger than their parents.

b. Living things that do not adapt will die out.

c. Small creatures adapt more quickly to their environments.

7. What could you expect to find living on an island where only tall plants grow?

a. animals with long necks

b. tall animals

c. animals with short legs

QUESTIONS

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8 LIFE SCIENCE

A Real Cool Bird: The Penguin

Many pen-guins live in theextremely coldenvironment ofthe South Poleregion. They cansurvive tempera-

tures as low as -60ºF because they havea thick layer of fat that insulates

( ns lats ) their bodies, or keeps themwarm. Unlike most birds, penguinscannot fly. On land, they waddle clum-sily along on their short legs. In thewater, they use their short, stubbywings like flippers. Penguins aregraceful, fast swimmers and can catchfish easily.

Most penguins raise their youngin large colonies called rookeries (rookrez). Usually, theybuild nests of stonesand lay one or twoeggs. However, the Em-peror penguin nestsin the following way:

The female, with-out building a nest,lays a single egg and

goes off to the sea to feed. Then themale penguin lifts the egg onto his feetand covers it with a flap of skin toinsulate it. He carries the egg this wayfor 60 days and moves around to keepfrom being covered with snow. Often,as many as 6,000 males will form agroup to keep their eggs and eachother warm.

The female penguin returns aroundthe time when the egg hatches. Shefeeds the young with food she bringsup out of her stomach. The malereturns to the sea for food. For thenext three to four months, the maleand female penguins take turns goingback and forth between the rookeryand the sea to feed their chick.

How arepenguins differentfrom otherbirds?

_

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LIFE SCIENCE 9

1. The word in the story that means “to keep warm” is __________.

2. A place where penguins raise their young is called a __________.

3. What do penguins have that fits over their unhatched eggs?

4. Which of the following is not true of penguins?

a. They can walk better than they can swim.

b. They are protective of their young.

c. They can survive the extreme cold.

5. Number the following events (1, 2, 3) in the order in which they occur

in the story.

_____ a. The male penguin goes in search of food.

_____ b. The male penguin carries the egg.

_____ c. The female penguin feeds her young.

6. Under which of the following headings would you list the penguin?

a. A Graceful Bird in Flight

b. A Land-Loving Bird

c. A Well-Insulated Bird

Use the scale below to answer question 7.

7. Based on the story, how would you rate the Emperor penguin’s ability to

feed its young?

a. 2

b. 5

c. 9

QUESTIONS

1 2 3 4 5 6 7 8 9 10

Fair Good Excellent

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