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What's Up in Science?Puzzles and Problem-Solving Activities to Build Science Literacy, Grades 6-10
By Robert G. Hoehn
John Wiley & SonsCopyright © 2004 John Wiley & Sons, Inc.
All right reserved.
Chapter OneSection 1 Preserved Evidence of Past Life
This section offers twelve activities related to the discovery of fossils. Fossils are the preserved evidence of past geological life. The remains of ancient plants and animals tell a great deal about their surroundings and the conditions under which they lived.
The puzzle exercises, open-ended questions, and brain builder activities in this section are designed to encourage students to use their creative and critical thinking skills. At the end of this section you will find a list titled Challenge Activities. These may serve as a reward for those students who desire extra credit.
1 What Fossils Have to Say
Fossils provide evidence of how life and environmental conditions have changed.
Fossils are preserved evidence of ancient geologic life. Ancient geologic life extends from the earliest ages recorded in rocks through the last Ice Age. A fossil may be an insect trapped in amber or a leaf imprint in a layer of sandstone. A saber-toothed cat, preserved in asphalt, and a woolly mammoth, frozen in ice, are examples of fossils. A scientist who studies fossils is known as a paleontologist.
What can be learned from studying fossils? Some reveal their shape, size, and where they lived; others tell a great deal about the conditions under which they lived. Regardless of what fossils say, one thing is clear: Certain plants and animals lived during past ages and then became extinct.
In 2000, a fisherman in Southern California spotted the fossilized remains of a 25-million-year-old organism thought to be an evolutionary link between a modern organism and its ancient ancestor.
1. Use the clues to help you identify the mystery organism. CLUES: a mammal; a fluke-powered, plankton-eater; three of the letters spell law. Answer: _________________
2. A paleontologist visited the site and collected parts of the skull and a tooth. He found a third bone. What was it? CLUE: The letters spelling the answer appear in these two words: one, bare. Answer: __________________________
3. Now it's your turn to find fossil animal bones. Let's say you discover four fossil bones while hiking in the hills. In order to receive credit for your find, you must write the bone names in spaces below the sketch. The groups of letters needed to spell the name of each bone are scattered along the hill. Place the bone names in alphabetical order. CLUE: Look for the names of the collarbone, thigh bone, kneecap, and breastbone.
PASS THE CHEESE
In 2001, a tiny skull reported to be 195 million years old turned up in China. Some scientists believe the organism could be an ancestor to humans. What kind of animal are the scientists talking about?
4. Unscramble five of the eight underlined letters below to reveal the answer. NOTE: Read the material below for a clue as well as pulling out the letters.
B i g b r a i n, c o m p l e x s k u l l
P r o b a b l y a t e b u g s a n d w o r m s
H a d c a n i n e - l i k e t e e t h.
The animal was a ________________________________.
Challenge Number One: What do you think this means?
0 degrees Centigrade Age 32 degrees Fahrenheit
Challenge Number Two: Plants grow in soil. Think of a way to get soil out of a fossil plant.
2 Long-Ago Life Forms
Scientists rely on fossils to provide evidence about Earth's past.
A slow-moving snail. A thorn-covered rosebush. A jellyfish drifting in the sea. These are examples of multi-cellular or many-celled organisms. Some live on land; others prefer a watery environment. And according to one theory, the multi-cellular organisms have been on Earth for 500 million years. A recent fossil find suggests the evolution of multi-cellular life forms may have started a billion years ago.
ONLY A TRACE
Scientists in India have found what appear to be tunnels left by prehistoric animals. They found the burrows in 1.1 billion-year-old rocks. There were no remains of the tunnel-digging creatures. The fossilized tunnels are known as trace fossils. A trace fossil provides evidence that a once-living organism lived there but left no remains behind. Even so, scientists study trace fossils and gain valuable information about prehistoric life.
1. What sort of animals can you think of that might dig tunnels?
2. Scientists believe the tunnels are twice as old as any other evidence for multi-cellular life yet discovered. What evidence might support this condition?
WHAT DO YOU KNOW ABOUT WORMS?
Some scientists think wormlike creatures tunneled through sand beds underneath a shallow sea covering what is now central India. Since no remains exist, scientists can't say for sure what these ancient organisms looked like. However, we do know a few things about modern-day squirmy worms.
3. Let's test your worm I.Q. Use the clues to help you complete the puzzle.
W __ __ __ __ __ a worm's short, jerky motion
O __ __ __ __ __ a worm's internal structures
R __ __ __ __ some worms have this body shape
M __ __ __ __ __ these worms live in the sea
S __ __ __ where some worms live
4. Look at the tunnels labeled A, B, and C in the illustration below. What do you notice about the diameter of the burrow holes?
I noticed the burrow holes ______________________________________________ _______________________________________________________________________ If you noticed that Tunnel A was much wider than Tunnel B, that will help you understand why scientists assume that the longer a tunnel was used by the organisms, the wider it became.
Challenge Number One: Think of a way to illustrate a WIDE tunnel using six letters and five dashes.
Challenge Number Two: Gophers are burrowing rodents. They leave holes or openings in the ground. What four letters in GOPHER spell a name that describes a small opening?
3 Footprints from the Past
Organisms become preserved as fossils in a variety of ways.
Fossils are preserved evidence of past ancient life. Scientists find many fossil bones, shells, and teeth in different parts of the world. These hard parts may stay buried for millions of years and undergo little change.
Paleontologists are scientists who study plant and animal fossils. Many fossils reveal secrets about life in the past, such as climate and environmental conditions. Most fossils are found in sedimentary rock.
MORE FOSSIL GOSSIP
Not all fossils come from the hard parts of organisms. Animal footprints, worm burrows, and trails of animals may harden as a mold. A mold is a cavity or imprint left by an organism. In time the mold becomes buried under layers of sedimentary material.
STEP BY STEP
In April 2000, a man in St. George, Utah, found about 150 dinosaur footprints in his backyard. Scientists say the footprints are representative of a mix of plant- and meat-eating dinosaurs that lived about 200 million years ago.
1. Read the statements below. Then arrange them in the order you think best describes how dinosaur footprints might turn into fossils. Write the statements in the empty spaces.
They plod through mud and leave footprints behind. They seek food along a river bank or lake shoreline.
Layers of mud, clay, or rock build up over the prints.
A mixture of sand and water covers the prints.
Millions of years pass by.
Several dinosaurs are present.
Fossilized footprints form in sedimentary rock. The mixture turns into cement and hardens.
They step in soft mud and sink.
2. What do you think dinosaur footprints tell scientists?
3. Circle the four parts of a foot hiding in the series of letters that could easily be identified in a fossil footprint.
o c r a n i n s t e p h e e l t o r i d c l a w e t o l t o e b y a k l e
4. If you discovered fossil tracks like those below, what would you say the animal was doing?
Challenge Number One: What four letters in DINOSAUR spell the name of rock material finer than gravel?
Challenge Number Two: Five letters in DINOSAUR spell radio. If you take a DINOSAUR's radio away, the remaining letters would spell the name of a star in the solar system. What is the name of the star?
4 Early Wings
Scientists base their explanations of nature using observations, experiments, and a variety of scientific models. These interpretations are tentative and subject to change.
SCIENCE IS ...
The process of science is based on producing knowledge about the physical world. A scientist may collect evidence by observing a subject over time or by gathering data from technical sources. Although much information has been collected over the years, many natural processes and events remain a mystery.
MAYBE OR MAYBE NOT
Many scientists believe birds evolved from dinosaurs. Fossils found in central Asia in 1969 by a Russian scientist have recently come under study. The fossils show a feathered reptile from about 220 million years ago. Surprisingly, this would be 75 million years BEFORE the first bird.
1. Does the fossil evidence prove that birds evolved from an earlier reptile rather than a dinosaur? Why or why not?
2. The fossil evidence indicates that the early reptile lacked the muscles needed for flight. If so, what might have been the function of the feathers?
3. According to the findings, the teeth and various body structures of the fossil remains are like those of birds. Is this enough evidence to say that birds evolved from earlier reptiles? Why or why not?
A paleontologist is a fossil scientist who, like a detective, gathers information to solve problems. A paleontologist often has to determine past events from a limited amount of evidence. Here's your chance to play Fossil Detective. Use the clues to help you solve the following problems:
4. Dr. Jennifer Ortiz, paleontologist, found an extinct amphibian bone. Name the bone and tell where it belongs in the animal's body. Fill in the blanks with the answers. Use the clues to help you find the answers.
CLUE: A straight line from the center of a circle to the surface.
CLUE: Not in the head or the pelvic zone. Try what lies next to the ulna bone.
The __ a __ __ __ s is found in the _________________________________.
5. Dr. Lewis Means, paleontologist, uncovered an extinct reptile bone. Name the bone and tell where it belongs in the animal's body. Fill in the blanks with the answers.
CLUE: Rearrange these groups of letters: le dib man
CLUE: It rests below the eyes and nose, and serves to rip its deadly foes.
The __ __ n __ __ __ l __ is found in the ______________________.
Challenge Number One: The feathered, four-legged reptile was 83 percent of one foot long. How long is that in inches?
Challenge Number Two: Use four letters in FOSSIL to describe the surface layer of earth.
5 Two Steps Ahead of the Rest
Fossils indicate that many organisms living long ago are now extinct. Lizards appeared about 200 million years ago. Some survived extinction and continue to live today.
A LOOK AT LIZARDS
Lizards are reptiles with long, slender, scaly bodies. They travel on four legs and carry a long tail. They live in hot, dry deserts all over the world. Lizards have external (outside) ears and legs with clawed toes on each foot. They can move their eyelids. Lizards measure from 5 cm (about 2 inches) to 12 feet in length. Some legless lizards bear a close resemblance to snakes.
In 2000, researchers in Germany found the fossil remains of a new species of lizard. They removed the fossil from a stone quarry. A quarry is a place where rocks are cut or blasted out of an area. The rocks are used for building materials.
1. Why were the researchers lucky to find a new species of lizard in the stone quarry?
2. After the researchers brought the 10-inch fossil to the lab, it took them two years to remove the rock that encased the lizard. Why do you think it took so long?
The new find amazed the researchers. The remains showed the lizard to be a two-footed sprinter able to outrun the hungriest predator. The ability to walk upright on two feet is known as bipedalism.
3. Many bipeds have long, strong hind legs. This gives them excellent jumping ability and allows them to run at a fast clip. Use this information to complete the drawing of the lizard.
OLDER THAN TIME
4. Scientists use a process called age dating to tell the approximate age of a fossil. They believe the lizard may be _______ million years old. Solve the problem and write the answer in the blank space. PROBLEM: Multiply 5.9 by 60. Add 2,140 to the answer. Subtract 372 from the total. Add 1,400. Now divide the total by 6, then subtract 297. NOTE: This problem is an arithmetic stretching exercise, not a model of age-dating.
Excerpted from What's Up in Science? by Robert G. Hoehn Copyright © 2004 by John Wiley & Sons, Inc.. Excerpted by permission.
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