Life Science Worksheet - · PDF file1 Life Science Worksheet GRADE LEVEL: Seventh Topic: Organization of Living Things Grade Level Standard: 7-1 Compare and contrast living things

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Life ScienceWorksheet

GRADE LEVEL: Seventh

Topic: Organization of Living Things

Grade Level Standard: 7-1 Compare and contrast living things.

Grade Level Benchmark: 1. Compare and classify organisms into major groups on

the basis of their structure. (III.2.MS.1)

Learning Activity(s)/Facts/Information

Central Question:How are groups of living things classified?

1. “Classification of Animals”

2. “Additional Resources”

Activity is attached

Resources

Ready Reference InstructionalFair

Process Skills:

New Vocabulary: vertebrates/invertebrates, cold/warm blooded, single cell,

multicellular, flowering/nonflowering, mammals, reptiles, amphibians

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CLASSIFICATION OF ANIMALS

KINGDOM: ANIMALIA

The animal kingdom consists of multicellular organisms that feed by ingestion. On the simplest level, they are madeup of tissues. As the animals become more complex, these tissues form organs. At the most complex level, thesetissues and organs form organ systems. The following is an overview of a portion of the animal kingdom.

PHYLUM: PORIFERA

(SPONGES)PHYLUM: CNIDARIA

(COELENTERATES)PHYLUM: PLATYHELMINTHES

(FLATWORMS)PHYLUM: NEMATODA

(ROUNDWORMS)

These sessile animalsattach permanently tounderwater objects.Characteristics include:! two cell layers with a

jellylike substance inbetween.

! a pore-covered bodywith a skeletal structurefor support.

! no head or mouth.! no tissues or organs.! digestion by collar cells.

These animals may haveone of two main bodyforms: cylinder-shapedpolyp or umbrella-shapedmedusa. This phylumincludes coral, jellyfish,sea anemones, and seafans. Characteristicsinclude:! two cell layers

separated by a jellylikesubstance.

! radial symmetry.! tentacles with stinging

cells.! a digestive cavity with

one opening.

Many of these animals areparasitic. This phylumincludes tapeworms andplanarians. Characteristicsinclude:! bilateral symmetry.! three cell layers.! a digestive cavity with

one opening.! no circulatory or

respiratory systems.

These animals are mainlyparasitic and live in soil,water, or dead tissue. Thisphylum includes trichinae,hookworms, andpinworms. Characteristicsinclude:! a tubular body with

bilateral symmetry.! a digestive tract with

two openings.! sexual reproduction.

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PHYLUM: CHORDATA

All chordates have a strong, flexible, rod-like notocord at some stage in their lives. Chordates also have pharyngeal gillslits and a hollow dorsal nerve cord.

SUBPHYLUM: CHORDATA

SUBPHYLUM: UROCHORDATA

(TUNICATES OR “SEA SQUIRTS”)SUBPHYLUM: CEPHALOCHORDATA

(LANCELETS)SUBPHYLUM: VERTEBRATA (VERTEBRATES)

Adult tunicates are marine, saclikeanimals that are usually sessile.Only free-swimming larvae have anotocord and other chordatecharacteristics.

Lancelets are thin, fish-like marineanimals. Characteristics include:! long, thin, flattened bodies.! no jaw and a lack of appendages.! basic chordate features

throughout life.

A vertebral column replaces the notochord inmost vertebrates. The vertebral columnencloses and protects the nerve cord.Vertebrates can be divided into sevenclasses. (For more information about theseclasses, see the next page.)

CLASS:AGNATHA

CLASS:CHONDRICHTHYES

CLASS:OSTEICHTHYES

CLASS :AMPHIBIA

CLASS:REPTILIA

CLASS:AVES

CLASS:MAMMALIA

CLASS: AGNATHA

(JAWLESS FISHES)CLASS: CHONDRICHTHYES

(CARTILAGINOUS FISHES)CLASS: OSTEICHTHYES

(BONY FISHES)

This class includes the jawlesshagfishes and lampreys.Characteristics include:! a cartilaginous skeleton! a notochord that is present

throughout the animal’s life! a rasping mouth that is used to

bore a hole in the side of prey,usually another fish

This class of jawed, cartilaginousfishes includes sharks, rays, andskates. Characteristics include:! a notocord at birth that is

replaced by vertebrae in adults! cold-bloodedness (typically)! a tail fin that is usually

asymmetrical! pectoral and pelvic fins! respiration through gills

This class of animals includesfishes such as catfish, eel,flounder, trout, and tuna.Characteristicsinclude:! a bony jaw

and skeleton! scales! paired

pectoral andpelvic fins

! a tail that is usuallysymmetrical

! cold-bloodedness (typically)! respiration through gills! oviparous (egg laying)

reproduction. A few haveviviparous (live birth)reproduction

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CLASS: AMPHIBIA

(AMPHIBIANS)CLASS: REPTILIA

(REPTILES)

Most amphibians live part of their lives in water and parton land. Most hatch and begin life in water, and mostreturn to the water as adults to mate and reproduce. Thisclass includes two main orders: Anura (frogs and toads)and Urodella (salamanders). Characteristics include:! the laying of eggs without shells.! growth from larva to adult through a process of

metamorphosis.! cold-bloodedness.! hibernation during harsh winters and estivation in

warm, dry climates.! smooth skin, though some toads have thick, leathery

skin (scales absent).! larval respiration through gills.! respiration in most land-dwelling adults through lungs,

and respiration in most water-dwelling adults through gills.Some adults have both lungsand gills.

! absorption of oxygen throughthe skin and through the liningof the mouth and throat.

Most reptiles belong to one of three main orders:Chelonia (turtles and tortoises), Crocodilia (alligators andcrocodiles), and Squamata (lizards and snakes).Characteristics include:! scales, which prevent the body from drying out.! respiration through lungs.! cold-bloodedness.! a venomous bit (in some cases).! growth, in many cases, by the shedding of skin

several times each year.! leathery-shelled eggs (in most cases), though some

give birth to live young.! hibernation during the

winter and estivation intropical climates.

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ADDITIONAL RESOURCES

Classification of Living Things - Organization of Living Things (III.2.MS.1)http://anthro.palomar.edu/animal/default.htm

This site is a teacher resource that covers the classification of living things as it relatesto the principles of taxonomy with a focus on human classification categories. Webexpeditions, an audio glossary and related sites enhances this site.

Five Kingdoms - Organization of Living Things (III.2.MS.1)http://www.brainpop.com/science/plantsandanimals/fivekingdoms/index.weml?&tried_cookie=true

Students will watch a short movie on the five kingdoms detailing the majorcharacteristics found within each kingdom. Students may take a quiz after the movie.Additional links to more information and extension activities are available.

Virtual Fish Tank - Organization of Living Things (III.2.MS.1)http://www.virtualfishtank.com/fishtank/fishtank.html

This site allows students to create his/her own fish by manipulating differentcharacteristics. These fish can then be "released" into a community tank. Each fish istagged and can later be caught and get details of it's life. Using information from theentire class, the fish can be grouped by features and determine which of the featuresaffects different aspects of its life.

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AssessmentGrade 7

ORGANIZATION OF LIVING THINGS

Classroom Assessment Example SCI.III.2.MS.1

Students will classify a variety of organisms into groups according to their structure. Studentswill use the following categories:

vertebrate/invertebrate categories of vertebrates:

• mammals• birds• fish• amphibians• reptiles

single-celled/multi-cellular flowering/non-flowering

These categories could be used in class games such as Jeopardy or Concentration.

(Give students rubric before activity.)

Scoring of Classroom Assessment Example SCI.III.2.MS.1

Criteria Apprentice Basic Meets Exceeds

Correctness ofclassification

Classifies with60-69% accuracy.



Classifies with100% accuracy.

Identification ofcommoncharacteristics

Lists one commoncharacteristic foreach category.

Lists twocommoncharacteristics foreach category.

Generalizesseveral keycharacteristics foreach category.

Compiles adetaileddescription ofcommoncharacteristics foreach category.

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Topic: Organization of Living Things

Grade Level Standard: 7-1 Compare and contrast living things.

Grade Level Benchmark: 2. Explain how selected systems and processes work

together in animals. (III.2.MS.4)


Central Question:How are the parts of living things adapted to carry outspecific functions?

1. The Living Skeleton (See Web Site)http://www.accessexcellence.org/RC/VL/xrays/The Living Skeleton has x-ray images of humanskeletons with descriptions and images. For example,students can see a picture of a normal arm bone andthen a fractured arm bone, they can also see images ofthe fractured arm after the surgery to fix it.

2. Virtual Frog Dissection Kit (See Web Site)http://www-itg.lbl.gov/vfrog/This award-winning interactive program is part of the"Whole Frog" project. You can interactively dissect a(digitized) frog named Fluffy, make movies, and playthe Virtual Frog Builder Game. The interactive Webpages are available in a number of languages.

Resources

Process Skills:

New Vocabulary: digestion, circulation, respiration, endocrine, reproduction,

skeletal, muscular, nervous, excretion, transport, growth, repair

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AssessmentGrade 7

ORGANIZATION OF LIVING THINGS


Students will collaborate in small groups to write and produce a play showing the functions ofthe circulatory, digestive, and respiratory systems. The groups will present their plays to anaudience other than their class, such as the PT0, other classes, and civic groups. Each group willsubmit their script for evaluation.




Accurateexplanation offunctions

Explainsfunctions of oneto two systems,but gives sketchydetails.

Explainsfunctions of threesystems, but giveslittle detail abouthow theyinterrelate.

Explainsfunctions of allthree systems anddiscusses howthey worktogether.

Explains in detailthe functions ofall three systemsand discusseshow they worksuccessfullytogether.

Effectiveness ofcollaboration

Participates withsome teammembers inwriting,performing, orproducing theplay.

Participates withmost teammembers inwriting,performing, orproducing theplay.

Participates withall team membersin writing,performing, orproducing theplay.

Participates withall team membersequally in writing,performing, orproducing theplay.

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Topic: Heredity

Grade Level Standard: 7-2 Explain how heredity determines characteristics.

Grade Level Benchmark: 1. Describe how the characteristics of living things are

passed on through generations. (III.3.MS.1)


Central Question:How are characteristics of living things passed onthrough generations?

1. “Heredity”

2. “Heredity Association Chart”

3. “Stages of Cell Division”

4. “Writing a Generalization”

5. “Acquired vs. Inherited Traits”


Resources

Kent County Collective CoreCurriculum

Process Skills:

New Vocabulary: reproductive cells, egg, sperm, chromosome, gene

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Academic Standard: The learner will (TLW) investigate how heredity andenvironment may influence/determine the characteristics of anorganism, how characteristics are passed on through generations andhow biologists trace possible evolutionary relationships among presentand past life forms.

HEREDITY7.1

A. Given pictures of the steps in cell division, TLW describe how characteristicsare passed on through generations.

Directions: 1. Sequence the pictures of cell division in the proper order bynumbering them from 1 through 5.

2. Beside each picture write a description of what is happeningto the genes and chromosomes.

___________________________________________________

___________________________________________________

___________________________________________________

___________________________________________________

___________________________________________________

___________________________________________________

___________________________________________________

___________________________________________________

___________________________________________________

___________________________________________________

___________________________________________________

___________________________________________________

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___________________________________________________

___________________________________________________

___________________________________________________

___________________________________________________

___________________________________________________

___________________________________________________

___________________________________________________

___________________________________________________

Criteria: Cell division steps are numberedcorrectly and description of genesand chromosomes are accurate.

Proficiency: 100%

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B. TLW use a Punnet Square to analyze how dominant and recessive genesinfluence the characteristics of an organism.

Directions: Complete the Punnet Square with the correct gene types, describethe characteristics of the offspring, and how the dominant andrecessive genes determined those characteristics.

For these examples: R = redr = white

1. Cross a red (RR) flowerwith a white (rr) flower

Description:_____________________________________________________________

_____________________________________________________________

_____________________________________________________________

2. Cross a red flower (Rr)with a red flower (Rr)

Description:_____________________________________________________________

_____________________________________________________________

_____________________________________________________________

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3. Explain in writing how two brown eyed parents can produce a blue eyed child.

_____________________________________________________________

_____________________________________________________________

_____________________________________________________________

Criteria: See resource 7.f Answer Key.

Proficiency: 100%

C. TLW differentiate between acquired and inherited traits.

Directions: List five human characteristics which are inherited and five whichare acquired and justify their designation.

INHERITED TRAITS JUSTIFICATION

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ACQUIRED TRAITS JUSTIFICATION

Criteria: Accurate categorization of traits.Justifications are reasonable.

Proficiency: 100%

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HEREDITY ASSOCIATION CHARTSTUDENT PAGE 7.1a

Write definitions for these key words:

Key Words Definitions

1. egg 1. ____________________________________________

_______________________________________________

2. sperm 2. ____________________________________________

_______________________________________________

3. embryo 3. ____________________________________________

_______________________________________________

4. nucleus 4. ____________________________________________

_______________________________________________

5. chromosomes 5. ____________________________________________

_______________________________________________

6. fertilization 6. _____________________________________________

_______________________________________________

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HEREDITY ASSOCIATION CHARTTEACHER PAGE

Key Words Definitions

1. egg 1. Carries the female inherited traits.

_______________________________________________

2. sperm 2. Carries the male inherited traits.

_______________________________________________

3. embryo 3. Developing fertilized egg.

_______________________________________________

4. nucleus 4. Contains genetic information and controls cell

activity.

5. chromosomes 5. Carries genes that transmit hereditary information.

_______________________________________________

6. fertilization 6. The joining of egg and sperm cells, which

combines male and female genetic information in the

embryo.

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STAGES OF CELL DIVISION7.1b

Draw each step of cell division:

Step 1 Step 2 Step 3 Step 4 Step 5

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WRITING A GENERALIZATION7.1c

PRELIMINARY INFORMATION

A generalization is a law, principle, or general statement. It is a statementwhich briefly describes characteristics, rules, explanations, reasons, or truthsthat will apply to many individual and specific examples.

Generalizations are usually only one or two sentences long.

Generalizations are used in science to show how a large number of differentobservations or situations are related to a single scientific idea. They are usedto help people understand and explain what they see and experience in theworld around them.

CRITERIA FOR WRITING A GOOD GENERALIZATION

1. Statement is brief, clear and to the point.

2. Is a large concept which includes all related variations and examples andcan be applied in all situations.

3. Adequately explains all observations related to the concept.

4. Uses complete sentences, correct spelling and appropriate punctuation.

REMEMBER

Compare your generalizations with the criteria above before calling it done.

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ACQUIRED VERSUS INHERITED TRAITS7.1e

DIRECTIONS1. Get two pieces of paper.

Head one paper, “INHERITED TRAITS”.Head the other paper, “ACQUIRED TRAITS”.

2. Place the human traits given in the list belowonto one paper or the other and write yourjustification for placing it there.

3. When you have classified all of the traits given,add three of your own traits to each paperand give a justification for each.

HUMAN TRAITS LIST

BROWN EYESRED HAIRBROKEN LEGSMALL NOSESCAR ON FOREHEADMUSICAL TALENTKNOWING THE NAMES OF THE CONTINENTSDARK SKINFRECKLESFEAR OF SPIDERSCHIPPED TOOTHCROOKED TEETHLONG HAIRATTACHED EAR LOBES

________________________________________

________________________________________

________________________________________

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ASSESSMENT ANSWER KEYPART B

7.1f

1. Cross a red (RR) flowerwith a white (rr) flower R R

r rR rR

r rR rR

Description:

All offspring are red flowers because each received one dominant gene

(R) for red color.

2. Cross a red flower (Rr)with a red flower (Rr) R r

R RR Rr

r rR rr

Description:Three-fourths of the offspring will be red because they contain at least

one dominant gene for red color and one-fourth of the offspring will be white

because it received two recessive genes for white color.

3. Explain in writing how two brown-eyed parents can produce a blue eyed child.

____________________________________________________________

____________________________________________________________

____________________________________________________________

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AssessmentGrade 7

HEREDITY


Using the Internet, encyclopedias, books, and magazines, students will select pictures of twodogs. Assuming one dog is female and the other dog is male, students will predict either throughillustration and/or written description what traits might appear in the offspring. Possible traits:hair color, hair length, leg length, tail, ears, distinct markings, eye color, nose length.




Completeness ofexplanation

Provides a limitedexplanation oftrait(s).

Provides aminimum of twotraits and areasonableexplanation forthose traits.

Provides adetaileddescription ofthree traits.

Provides adetailed writtenand visualdescription ofthree or moretraits.

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Topic: Heredity

Grade Level Standard: 7-2 Examine how heredity determines characteristics.

Grade Level Benchmark: 2. Describe how heredity and environment may

influence/determine characteristics of an organism. (III.3.MS.2)


Central Question:In what ways do living things adapt to survive in theirenvironments.

1. “Trait Combos”

2. “Endangered Species”


Resources

Process Skills:

New Vocabulary: inherited, acquired

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TRAIT COMBOSby Sue Shollenbarger

INTRODUCTORY STATEMENTThrough various activities students collect and analyze data on similarities and differencesin their physical appearance.

MATH SKILLS SCIENCE PROCESSESUsing fractions ObservingUsing decimals Reporting dataDetermining probability Classifying and sorting dataUsing a dichotomous key Interpreting dataFinding combinations Making and testing hypothesesCollecting statistics

MATERIALSMirrorsCalculators optional

KEY QUESTIONSWhat is the probability that people have certain traits and combinations of traits?

BACKGROUND INFORMATIONProbabilityProbability is a tool used to do statistical work. It involves the mathematical prediction ofsomething happening in a larger group by examining the same thing in a smaller samplegroup. As an illustration, if we were able to obtain information about the ear lobes of everyperson in the world, we would know for sure how many of these in the total population hadfree ear lobes. Since this is not possible, we need a way to use a smaller number of people(a sample) and find out how many of them have free ear lobes; then, we need to expressthe resulting data in a way that we show its relationship to the data that the total populationof the world would probably have. The larger the sample, the more reliable the databecomes, because the sample size is closer and closer to the total population.

When we use a sample, something smaller than the total population, we must rememberthat there will probably not be exactly the same proportion of any trait, like free ear lobes, asthere would be in the total population. In this activity, the sample utilized may be one classor several classes; the larger the sample, the more reliable the resulting data.

The estimated probability is the ratio of the number of students with a chosencharacteristic to the number of students in the sample. This is expressed as a ratio whichmay be read, "Out of every _____(denominator) people, ______(numerator) have free earlobes." The ratio may then be converted to a decimal by dividing the numerator by thedenominator. The decimal form is especially useful when the same study is repeated with asample of a different size; you can compare the data from the two studies.

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GENETIC TRAITSHeredity has influenced everyone's life. People tell you thatyour hands are just like your mother's or that your facialfeatures identify you with a certain branch of the family. Otherless visible traits include susceptibility to some diseases, lifeexpectancy, and some behavioral patterns. The total numberof human traits is unknown. There are more than five billionpeople on earth, and each one has a different combination oftraits.

The foundation for much of the research in the area ofheredity was laid by an Augustinian teaching monk namedGregor Mendel, who lived during the latter part of thenineteenth century. As he worked in the monastery garden helping to raise vegetables, henoticed that various garden pea plants had differing characteristics, such as blossom color,height, and seed characteristics.

Mendel conducted experiments to change the normal self-pollinating pattern of these plants.He cross-pollinated one plant (purple flowers) with another (white flowers), planted theresulting seeds, and observed the results. By repeating his experiments with other plantsand then with bees and mice, he made what are considered major scientific discoveries. Inthis area he developed what is often called Menders First Law; The Law of Dominanceand Recessiveness.

Dominance means that in a pair of genes, one tends to be superior or dominant andthe other recessive. If there is one gene for free ear lobes and another for attached earlobes, the free ear lobes gene tends to be dominant. If both parents have free ear lobes, itis more likely that most of their children will have free ear lobes than that will have attachedear lobes.

In this activity four traits, usually considered to be hereditary, are involved. The choice ofthese was limited since it was necessary to have visible characteristics of which thedominant and recessive manifestations were comparatively easy to identify.

The genetics aspect of this activity is less formal than the probability aspect, andconsequently the goals are more modest. It is hoped that students will learn a few basicconcepts, such as the difference between dominant and recessive traits and the reality thatpeople are made up of many different combinations of traits. Discussions on genetic traitswill probably be handled during the statistical activities rather than in separate topicalsessions. If interest in genetics persists, it is suggested that you consult books on genetics,heredity, and biology for a better understanding than is possible in this simplifiedexplanation.

MANAGEMENT1. In doing the activities on page I, students should work in pairs. On page 2-4, the

activities can best be done if students are in cooperative groups of four or five students,although you may need to work through the mathematics with the whole class. Page 5should also be done with the whole class, but it is clearest if each student has a copy ofthe activity sheet.

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2. There are many dominant (and recessive) genetic traits in humans. For this activity wehave chosen four traits considered by many authorities to be dominant::

• free ear lobe: the lobe joins theside of the neck above the lowestpart of the lobe (student must haveat least one free ear lobe)

• widow's peak: the foreheadhairline forms a definite point

• can roll tongue: person can rollthe sides of the tongue togetherinto a kind of tunnel, using the lipsif necessary

• right-thumbed: when hands arefolded, the right thumb is on topfrom the student's viewpoint

3. Before copying page 2, fill in with class names. This is the only page which need not becopied for every student unless you wish to do so; post one completed copy and letstudents refer to it.

4. This activity has a dual purpose. It is intended to help students gain an introductoryunderstanding of probability by observing physical characteristics and grouping theminto combinations or combos. It is also intended to afford a rich opportunity to introducethe idea of dominant and recessive traits, a basic concept in the area of heredity.

PROCEDURE1. Discuss the key question: "In what ways are we alike and different?" Let students

discuss similarities and differences without much guidance, so that they discover someof these for themselves: height, eye color, hair color, dimples, widow's peak, lip shape,etc.

Page 12. Guide students to understand the use of the terms observer and subject. Remind them

that the person collecting the data is the observer, and the person being observed (thepartner) is the subject.

3. Define each dominant trait and identify a student possessing it. (Note that everyone hasthe trait, but not everyone has the dominant trait.

4. Discuss what size sample you should use. Although most classes will use the classgroup as the sample, it is useful to have students discuss this and make the decision tohelp them understand what a sample is.

5. Partners answer the questions as they observe their partners. After they finish the page,encourage them to use mirrors to check themselves and compare with what theyobserved in their partners.

Page 26. For pages 2-4, students work in cooperative groups with whole-class discussions as

necessary. They also change from collecting data on their partners to collecting data onthemselves.

7. Beside their names on the class record sheet, students record "y" (yes) or "n" (no) toshow whether or not they have each of the four dominant traits. Post in a centrallocation where students can refer to it.

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Page 3Part 1: Finding the estimated probability (EP) for one trait.8. In this section, students predict the probability of people in the general population

(everyone in the world) having each of the four dominant traits. To begin, they fill inColumn 1 using the data obtained on Page 2.

9. In Column 2 note the total number of students in the class (or in the sample if otherthan the class); repeat beside each dominant trait.

10. In Column 3 construct the estimated probability as a ratio. Make a ratio for eachdominant trait by combining Columns 1 and 2 as shown. (See background)

11. To express the estimated probability as a decimal (a more useful form for comparisonpurposes), divide the numerator by the denominator. Write the result in Column 4.

12. To express as a percentage, multiply the figure in Column 4 by 100.13. To predict how many people will have this trait in a group of 1000 people, multiply the

figure in Column 5 by 10.

Part 2: Finding the EP for two dominant traits14. Under "Trait Combos" student lists all possible combinations of two traits. (6 in all -

extra spaces are provided to avoid giving students necessary clues to the correctnumber of answers. )

15. Find the number of students who have each of these combos.16. Guide students to fill in the rest of the table as they did in Part 1.17. As a class, compare the data from Part I with that of Part 2.18. Arrange the combos in order, starting with the most probable.

Page 4Part 3: Finding the EP for three dominant traits19. List the combinations of three dominant traits. (four in all)20. Find the number of students who have each trait combo. Fill in the rest of the table as

before.21. List the combos in order.

Part 4: Finding the EP for all four dominant traits22. How many students have all four dominant traits? Fill in the chart to help students

realize the mathematical implications.23. Help students to compare all the data to see what changes from Part I to Part 2 and

so on. Emphasize the comparison of Column 6 in the various tables.

Page 5 - Dichotomous key24. To use this, it is least confusing if each student has a copy.25. Start with the whole class. This is a group they are all in, so everyone will circle the

words "all students".26. The class will divide itself into two groups one that has free ear lobes and the other

that has attached (not free) ear lobes. Everyone is in one group or the other. Theyshould circle the trait (either dominant or recessive) of their own groups.

27. The group with free ear lobes is divided into two groups, those who can fold theirtongues and those who can't. They decide which group they are in and circle it.

28. Those with attached ear lobes do the same thing.29. Continue in this way, working with one circled group at a time.

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30. When the group that can roll tongues and are right-thumbed is identified, havestudents write their initials on the top line. Continue doing this with each of the othergroups. All students should have their initials on one of the lines.

DISCUSSION1. Discuss these terms; observer, subject, sample.2. How do you tell the difference between free and attached ear lobes? Is there a third

type of ear lobe?3. How would you describe a widow's peak?4. What is the difference between a dominant and a recessive trait?5. (Page 2) What do you notice about the number of students in the sample that have

the dominant traits?6. (Page 3, Part 2) What is the estimated probability ratio for a person in our sample to

have free ear lobes and a widow's peak (or free ear lobes and not a widow's peak)?7. What would happen if we repeated the activity with a larger sample? (Data would be

more reliable)8. Have a class discussion to review what has been learned during the activity. See if

students can explain:• the concept of estimated probability• how to obtain estimated probability• the difference between dominant and recessive traits• how millions of people can have different combinations of dominant and

recessive traits (as shown on Pages 3 and 4)• how we are alike and yet different from one another

Extend the discussion as appropriate for your group.

EXTENSIONS1. Do part of all of the activity with a larger sample. Compare the resulting data,

especially the estimated probability.2. Change one of the traits to "has a dimple" and repeat the activity. What happens to

the data?3. On Pages 3 and 4, use the same tables to record data for recessive traits (e.g.,

attached ear lobes, cannot fold tongue, etc.)4. On Page 5, note for each category the number of students in each group. This is a

checking device, since all students should be accounted for, both those with dominantand those with recessive traits.

5. Build a bulletin board of a Venn diagram with two circles inside a rectangle. Label thecircles with two traits. Have students write their names in the proper regions.

CURRICULUM CORRELATIONSocial StudiesDiscuss prejudices based on genetic traits. How much alike are we according to thedichotomous key on Page 5? How reasonable or logical are such prejudices?

Language ArtsHave students do research on heredity or the life of Gregor Mendel.

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HOME LINKSEncourage students to build a dichotomous key of dominant traits in their families. Note thecaution in the Background section.

The editors are indebted to Ben Van Wagner and Richard Thiessen for their help in editingthis activity.

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TraitCombos

Observer_____________________

Subject______________________

What is the probability that people have certain traits or combinations of

traits?

1. Use these four traits for your study.

2. What size sample do you plant o use to obtain adequate data? Explain your

decision.

_______________________________________________________

_______________________________________________________

_______________________________________________________

3. Take a good look at your partner.

Yes No

Does your partner have free ear lobes?

Does your partner have a widow’s peak?

Can your partner roll his or her tongue?

Is your partner right-thumbed?

MAY/JUNE 1992 © 1992 AIMS EDUCATION FOUNDATION

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TraitCombos

CLASS RECORD SHEET Page 2

ear peak roll thumb ear peak roll thumb

TOTALS TOTALS


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Page 3

Name _________________

TraitCombos

Part 1: Find the estimated probability (EP) for a person to have 1 of these

dominant traits: free ear lobe, widow’s peak, ability to roll tongue, and right-

thumbed.

Traits

1

total #

with each

trait

2

Actual #

in sample

3

EP (ratio):

Col. 1/ Col.

2

4

EP as a

decimal

5

EP as % of

sample

6

Predicted

# per

1000

free ear lobes

widow’s peak

can roll tongue

right-thumbed

Part 2: Find the EP for a person to have a combination of 2 dominant traits.

Trait combos:

free, peak, roll,

right

1

total #

with each

trait

2

Actual #

in sample

3

EP (ratio):

Col. 1/ Col.

2

4

EP as a

decimal

5

EP as % of

sample

6

Predicted

# per

1000

Arrange the trait combos in order from most probably to least probable.

________________________________________________________

________________________________________________________


34

Page 4

Name _________________

TraitCombos

Part 3: Find the EP for a person to have a combination of 3 dominant traits.

Trait combos:

free, peak, roll,

right

1

total #

with each

trait

2

Actual #

in sample

3

EP (ratio):

Col. 1/ Col.

2

4

EP as a

decimal

5

EP as % of

sample

6

Predicted

# per

1000

Arrange the trait combos in order from most probable to least probable

________________________________________________________

________________________________________________________

Part 4: Find the EP for a person to have all 4 dominant traits.

Trait combos:

free, peak, roll,

right

1

total #

with each

trait

2

Actual #

in sample

3

EP (ratio):

Col. 1/ Col.

2

4

EP as a

decimal

5

EP as % of

sample

6

Predicted

# per

1000

What observations can you make? _______________________________

________________________________________________________


35

TraitCombos

Name _______________ Page 5

can rolltongue

right-thumbed __: ________________

widow’s peak

left-thumbed __: ________________

freeear lobes

can’t rolltongue

right-thumbed __: ________________

left-thumbed __: ________________

all students

can rolltongue

right-thumbed __: ________________

no widow’speak

left-thumbed __: ________________

can’t rolltongue

right-thumbed __: ________________

left-thumbed __: ________________

can rolltongue

right-thumbed __: ________________

widow’s peak

left-thumbed __: ________________

attached earlobes

can’t rolltongue

right-thumbed __: ________________

left-thumbed __: ________________

can rolltongue

right-thumbed __: ________________

no widow’speak

left-thumbed __: ________________

can’t rolltongue

right-thumbed __:________________

left-thumbed __: ________________


36

ENDANGERED SPECIES

PURPOSETo realize the impact of endangered species on our environment today and in the future.

PROBLEMThe John Ball Park Zoo is looking to purchase an endangered species. Your job is tochoose a specific endangered species and influence the zoo officials to buy the animal youhave chosen by delivering a short, informative presentation. It should include generalinformation about the animal and why the animal would benefit by being at the zoo, as wellas why the zoo would benefit by having the animal.

ASSIGNMENT1. Prepare an oral and visual presentation about the endangered species your group has

chosen. Your presentation should include the following general information.• Common name/Scientific Name• Class (insect, fish, amphibian, reptile, bird, mammal)• Description: size, weight, color• Unique characteristics and/or behavior• Food-diet• Habitat• Reproduction characteristics (number of offspring, destination period)• Endangered status• Factor(s) that threaten or endanger animals• Role in ecosystem (relationship among other organisms/possible effects due to

changes in one population in a food web on other populations)

2. Prepare a written outline of your presentation that will be turned in prior to giving yourpresentation. This outline will include a bibliography of sources used. You may useonly one encyclopedia. MINIMUM OF THREE RESOURCES.

EXIT STANDARDSEffective communicatorsInvolved citizensSelf-directed learnersCooperative contributorsCreative producersCritical thinkers

37

ENDANGERED SPECIES PRESENTATIONCRITERIA

Presentation Quality Outline Visual

• 8-10 minutes

• covered all major facts

• persuasive (benefits toanimal and zoo)

• actively involvesaudience (questioning/awareness)

• gives each groupmember an equallyimportant role

• outline and bibliographyin proper form

• presentation followsoutline

• more than threeresources

• incorporated fully intopresentation

• appealing/easy to read

• information is wellorganized within thespace

• 5-7 minutes

• missing 1-2 facts

• somewhat persuasive

• is aware of audience

• gives each groupmember a role

• few errors in outline andbibliography

• presentation somewhatfollows outline

• three resources

• visual explained notincorporated

• somewhatappealing/most of theinfo is easy to read

• organization is adequate

• over 10 minutes, under5 minutes

• missing 3-4 facts

• merely informative

• show little/no awarenessof audience

• some group membershave no role

• outline and bibliography

• presentation does notfollow outline

• less than threeresources/more thanone encyclopedia

• visual not fully explained

• slightly appealing/info isdifficult to read

• organization is poor

38

ENDANGERED SPECIES PRESENTATIONCRITERIA (continued)

Delivery Social Skills

• clear and good volume

• fluent

• occasional reference to notes

ALWAYSstays in groupis on taskuses quiet voicelistens actively in groupmakes contributions

• somewhat clear - difficult to hear attimes

• stumbles occasionally

• heavy reliance on notes

USUALLYstays in groupis on taskuses quiet voicelistens actively in groupsmakes contributions

• difficult to hear and understand

• stumbles frequently

• reads off paper

OCCASIONALLYstays in groupsis on taskuses quiet voicelistens actively in groupmakes contributions

39

ENDANGERED SPECIES PRESENTATIONRUBRIC GRID

Criteria Assessment

1. Presentation Quality

4Excellent

3-2Satisfactory

1-0Not Satisfactory

Length of presentation

Facts covered

Persuasive

Audience involvement

Equal roles

2. Outline/Bibliography

4Excellent

3-2Satisfactory

1-0Not Satisfactory

Proper form

Presentation guide

Resources

3. Visual

Incorporation

Visually appealing

Organization

4. Delivery

Projection

Fluency

Eye contact

5. Social Skills

Social Skills

TOTAL POINTS

40

Name: ______________________________

Name of animal: ________________________

ANIMAL PROJECT EVALUATION

Respond to the following questions honestly and carefully. This evaluation will beconsidered before final grades on this project will be issued.

1. Which animal do you think the zoo should adopt? _________________________

_________________________________________________________________

_________________________________________________________________

2. Rate this project using a scale of 1 (poor) to 5 (excellent).

_____ Was there enough information on your animal?_____ Did you learn valuable information about your animals._____ Did you learn valuable information about other endangered animals._____ Do you feel this would be a good activity to do in future years?_____ Was it helpful to have both your English and Science teacher involved it

this project? Please explain your response.

________________________________________________________

________________________________________________________

_____ Did you enjoy this experience?

3. Please list two things you feel your group did well.a. __________________________________________________________b. __________________________________________________________

4. Please list one thing you feel your group could improve.a. __________________________________________________________

5. Do you feel that anyone in your group deserves extra credit for this week on thisproject? If so, please explain why.

41

6. Do you feel that anyone in your group did not take on enough responsibility orfollow through on their responsibilities? If so, please explain why.

7. Please write down any comments or suggestions you may have about this projectthat will help us make improvements for next year.

8. In carrying out this project, in what way(s) do you feel you were a(n):A. EFFECTIVE COMMUNICATOR:

B. INVOLVED CITIZEN:

C. SELF-DIRECTED LEARNER:

D. COOPERATIVE CONTRIBUTOR:

E. CREATIVE PRODUCER:

F. CRITICAL THINKER:

42

AssessmentGrade 7

HEREDITY


Students will construct a model that shows the traits that a futuristic insect might acquire as aresult of a current environmental change.

Students will present their models to the class and explain their answers to the followingquestions:

Why did the insect acquire those traits? What two changes did the insect undergo? What factors might have influenced natural selection? What traits might be passed on from this insect to its future offspring to ensure reproductive

success?




Accuracy ofModel

Develops a modelshowinginaccurate traitsof a futuristicinsect.

Develops a modelthat shows thetraits of afuturistic insect.

Develops anaccurate modelthat clearly showsthe traits of afuturistic insect.

Develops an in-depth, accuratemodel that clearlyshows the traits ofa futuristic insect.

Presentation ofmodel

Presentsinformation in anincomplete,difficult tounderstandmanner.

Presentsinformation in aneasy tounderstandmanner.

Presentsinformation in aninteresting, easyto understand,creative manner.

Presentsinformation in aninteresting, easyto understand,creative mannerwith additionalvisuals.

43



Topic: Ecosystem

Grade Level Standard: 7-3 Describe patterns of interdependence and

interrelationships in various ecosystems.

Grade Level Benchmark: 1. Describe common patterns of relationships among

populations. (III.5.MS.1)


Central Question:How are parts of an ecosystem related and how do theyinteract?

1. “How can the Number of a Population be Estimatedfrom a Sample”

2. “Mutualism and Commensalism” (Seehttp://www.nearctica.com/ecology/pops/symbiote.htm)


Resources

Process Skills:

New Vocabulary: predator, prey, parasite, competition, mutually beneficial

44

HOW CAN THE NUMBER OF A POPULATION BEESTIMATED FROM A SAMPLE?

BACKGROUNDWhen biologists want to know the number of living things in a given area, they canselect from two different counting methods. The best data would be obtained bycounting the entire population. However, this counting method is impractical andvery time-consuming. The other method is to count a small sample of thepopulation. The sample counted must represent the entire population. If thesample is not a true representative of the given population in question, then the datacollected are biased and therefore inaccurate. The random selection of areas inwhich to count organisms eliminates bias in the selection. As a result, everymember of the population stands an equal chance of being counted. In thisinvestigation, you will demonstrate the technique of counting a random sample ofpopulation. You also will count a sample from an actual population.

OBJECTIVEAfter completing this investigation, you will be able to

Compare biased selection with random selection. Conduct a random sampling of a given population. Estimate the total number of population based on a sampling.

MATERIALS(per student)

• 1 sheet plain white paper• metric ruler• felt-tipped pen

PROCEDURETechnique—Counting a Random Sample of a Population• Draw a 20 cm x 20 cm square on a sheet of plain white paper. With a felt-tipped

pen, mark 200 dots anywhere within the measured square.• Divide the 20 cm x 20 cm square into 100 equal squares. Each small square will

measure 2 cm x 2 cm. Number the small squares from 1 to 100.• Randomly select 10 numbers out of 100. Record the 10 numbers in Table 63-1

on the Answer Sheet.• Count the dots in each of the randomly selected small squares. Count the dots

that are completely within each square. Also count those dots that are touchingthe left and top lines of each square record the number of dots in each of therandom selected squares in Table 63-1 on the Answer Sheet.

• Calculate the average of the total number of recorded in Table 63-1. Record theaverage in Table 63-1 on the Answer Sheet.

• Multiply the average number of the random squares by 100, the total number ofsquares in the square. Record this number in Table 63-1 on Answer Sheet.Complete numbers 1 through 4 on the Answer Sheet.

45

HOW CAN THE NUMBER OF A POPULATION BEESTIMATED FROM A SAMPLE?

ANSWER SHEET________________________________________________

Table 63-1

Square Number Number of Data

Totals

Average

X 100

1. How accurate was your estimate from the random count compared to the actual totalnumber of dots.______________________________________________________________________

2. Was there any possible bias in the number selected from the 100 small squares?______Explain your answer.______________________________________________________________________

______________________________________________________________________

3. Was there any bias in the original marking of dots on the paper? __________________Explain your answer.______________________________________________________________________

______________________________________________________________________

4. Would the results be closer to the expected number if an average of your classmates’results were taken? ______________________________________________________Explain your answer.______________________________________________________________________

______________________________________________________________________

46

AssessmentGrade 7

ECOSYSTEM


The teacher will present small groups with the following scenario:

"Survivor II, The Next Generation" is coming out next season. The rules have changed slightly.This season, teams of survivors will be placed on separate islands where they will remain for onemonth.

The teacher will select a variety of islands from around the world and write the names of theislands on slips of paper. Each team will draw a slip and then research the island. The winningsurvivors will be chosen as a result of their fine scientific journaling. To win the one million, youmust discover a way to show all of the relationships you see among the different islandpopulations on Earth.

Team journals should include the following information:

predator/prey relationships parasitic relationships (parasite/host) competitive relationships mutually beneficial relationships




Description ofrelationships

Lists onerelationship.

Describes tworelationships.

Describes twocompleterelationships.

Describes three ormore completerelationships.

47



Topic: Ecosystem

Grade Level Standard: 7-3 Describe patterns of interdependence and

interrelationships in various ecosystems.

Grade Level Benchmark: 2. Describe the likely succession of a given ecosystem

over time. (III.5.MS.4)


Central Question:How do communities of living things change over time?

1. “Succession of Ecosystem” (seehttp://www.plainedge.ourschools.org/teachercenter/succession.htm)

2. “A Forest Forever” (seehttp://www.teachtheteachers.org/projects/MBergey/navbar.htm)

Resources

Process Skills:

New Vocabulary: succession, stages, climax, community, pioneer

48

AssessmentGrade 7

ECOSYSTEM


Each student will work with a partner to draw a storyboard of the stages of succession in aspecific ecosystem of their choice. Possible choices may include terrestrial or aquatic ecosystems– farm fields, beaches, sand dunes, fence rows, barren rocks, abandoned wetlands, ponds, orlakes. Students will research this ecosystem. They will illustrate their research using a flow chart,diorama, 3-D display, or multimedia presentation. The project should illustrate the likely stagesof succession of a given ecosystem from a pioneer species to a climax community. They willpresent their project to another class.




Accuracy ofsequence

Illustrates nosuccessionalstages frompioneer to climaxcommunities.

Illustrates a fewsuccessionalstages frompioneer to climaxcommunities.

Illustrates mostsuccessionalstages frompioneer to climaxcommunities.

Illustrates detailedsuccessionalstages frompioneer to climaxcommunities.

Quality ofcontent

Includes fewdetails and listsfew organisms.

Includes somedetails and listsdifferentorganisms.

Includesimportant detailsand lists differentorganisms.

Includes manyadditional detailsand lists a diversevariety oforganisms.

49

Physical ScienceWorksheet


Topic: Motion of Objects

Grade Level Standard: 7-4 Compare common forces and motions of objects in

two dimensions.

Grade Level Benchmark: 1. Qualitatively describe and compare motion in two

dimensions. (IV.3.MS.1)


Central Question:How can the motion in two dimensions be describedand compared qualitatively?

1. “Hover Craft”

2. “Rocket Balloons”

3. “Experiencing Forces”


Resources

Process Skills: Observing, Predicting, Estimating, Applying, Generalizing, Recording data,Controlling variables, Inferring, Classifying

New Vocabulary: two-dimensional motion, speed, direction, change in speed and

direction

50

INTRODUCTORY STATEMENTStudents will learn more about how a rocket works and how the force of the enginescan be controlled.

MATH SKILLSTimingAveraging

SCIENCE PROCESSESObservingPredicting and estimatingApplying and generalizing

MATERIALSBalloons–long and/or round (At least at first, give all students the same size andshape.)Soda strawsMasking tapeStopwatch(es) or a watch with a sweep second handRuler or measuring deviceStudent worksheet (Hover Craft)

KEY QUESTION“How can you overcome gravity and make a balloon hover in the air in a stableposition?”

BACKGROUND INFORMATIONThis investigation will demonstrate how a spaceship may someday land on Earth orhow the LEM (Lunar Escape Module) piloted by Neil Armstrong first landed on themoon. Certainly students realize that an object landing in a vertical position mustslow its speed so as not to impact the landing area with such great force that severedamage to craft and pilot will result. Here, students will control the escape of airfrom the balloon in such a way that the force of the thrust will be sufficient only tokeep the balloon up, not enough to make it go up.

This is also the principle that is used by the British Royal Air Force with the HarrierJet. This airplane can take off or land in a vertical position and may also hover in astationary position, as a helicopter does.

51

MANAGEMENT SUGGESTIONS1. The size and shape of the balloon can cause differences in a way the balloon will

fly. Shape and size may be added later as a variable or extension.2. The size of the straw (weight and diameter) will affect the flight of the balloon.

This may be added as a variable or extension later.3. Make sure the straws are taped to the balloon securely so that no leaks exist.4. Groups of three will work best, with one student to release the balloon, one

observer to tell when to start and stop the clock, and a timer. A fourth could beadded if necessary.

5. Allow 45-60 minutes for construction, flying, recording, and discussion.

PROCEDURE1. Students will need, for each group, at least one balloon, two (or more) straws,

masking tape, and a timing device.2. Students need to crimp the end of one straw and insert it into the end of the

other straw. This will allow them to adjust the length of the straws.3. Insert the straw(s) into the end of the balloon and tape with no leaks allowed.4. With observers ready, measure and record the length of the straw, inflate the

balloon and release it.5. The object of this activity will be to adjust the straws in such a way so as to keep

the balloon up (in the air) as long as possible.6. Repeat as desired or necessary.

DISCUSSIONWhat does make an aircraft hover? (The force of the engines is constricted untilthere is only enough force left to overcome the force of gravity on the weight of thecraft.)

52

53

ROCKET BALLOONSCHART #1

INTRODUCTORY STATEMENTStudents will learn how a rocket works.

MATH SKILLSMeasurementAveraging

SCIENCE PROCESSESRecording dataObservingControlling variables

MATERIALSSausage-type balloonsSoda strawsMasking tapeString (monofilament fishing line works best)Measuring tape or meter stickStudent worksheets

KEY QUESTION“How does a rocket work? What gets it off the ground?”

BACKGROUND INFORMATION1. In this initial investigation, we are going to consider the relationship between the

length of the balloon and distance which it travels.2. Logically, the more air in the balloon, the longer it will be and, therefore, the

farther it will travel.3. This is an example of Newton’s Third Law of Motion: For every action there is

an equal but opposite reaction. The backward thrust of the air produces theforward motion of the balloon.

MANAGEMENT1. This activity will take one to two class periods, or 45-90 minutes.2. Try to have as many different lines strung as possible to use as tracks for the

balloons to run on. Hang the strings at student eye level.3. This activity works best in small groups.4. Assign jobs which can be rotated: one person to (a) launch the balloon, (b)

record the distance, (c) observe and check.5. If room is limited, you will have to lessen the size of the balloons.

54

PROCEDURE1. As air escapes from the balloon, the rocket will travel along the track (string).2. Thread string through a straw and attach the ends of the string to a wall or other

object. Stretch the string as tightly as possible.3. Blow up a balloon to the desired size, measure it, and record the data.4. Tape the balloon to the straw. It is best to tape the soda straw and balloon

together near the opening of the balloon, with tape pieces fairly close together.5. BE CAREFUL - don’t let the air out yet!6. Release balloon. Observe and record the distance it travels.

WHAT THE STUDENTS WILL DO1. Students will make balloon rockets and measure, record the length of the

balloon.2. Students will attach the balloon rocket to the track.3. Students will measure the distance the balloon travels when it is released.4. Students will record data.

DISCUSSION1. Why does the balloon travel along the string? (Thrust: the backward thrust of the

released air creates the forward motion of the balloon.)2. What happened as the length of the balloon was increased? (From student

observation.) Why? (More air was released.)3. What factors could cause a balloon not to go as far as it should?

55


Balloon length vs. Distance Traveled

BalloonLength

Distance Traveled AverageDistanceTrial 1 Trial 2 Trial 3

1.

2.

3.

4.

5.

THE SKY’S THE LIMIT! © 1987 AIMS Education Foundation

56


INTRODUCTORY STATEMENTStudents will explore the ways in which the angle of ascent might affect a rocket.

MATH SKILLSMeasurement – linearMeasurement – anglesAveraging


MATERIALSSausage-type balloonsSoda StrawsMasking tapeString (Monofilament line, again)

KEY QUESTION“Does the distance a balloon rocket travels change as the angle of ascentincreases?”

BACKGROUND INFORMATION1. Since the balloon will have to travel up the line at an angle, some of the thrust

will be expended in this effort.2. We will be comparing the distance traveled when the rocket is traveling at

different angles.

MANAGEMENT1. This activity works best in small groups and will take 45-60 minutes.2. Try to have as many different lines strung as possible.3. Again, assign jobs which can be rotated—a launcher, a recorder and a checker.4. Hopefully, if students are careful when checking the measurements of an angle

when they move the lines, they will also be careful in the physical process ofmoving the lines.

5. Again, if space is limited, lessen the size of the balloon.PROCEDURE

1. Follow steps 1-6 of the procedure in part A of this investigation.

57

2. After each distance is recorded, change the angle of the track the rocket balloonmust travel. To measure the angles easily, cut off the bottom margin of aclinometer and use it.

3. Repeat the above procedure for the different angles of the string.4. After making rocket balloons and measuring their lengths as before, students will

measure the distance the balloons travel along the track or line.5. Students will retest their balloons (blown up to the same length each time) each

time that the angle of the track is changed.6. Students will record the data and compare the distance traveled at each angle.

DISCUSSION1. What happens when the line is changed from level flight to a different angle or

flight?2. Does it take more or less power to lift the balloon rocket “off the ground” when

the line is at an angle than it does when it is level? Why?3. Does it take more or less power to move the balloon rocket the same distance

along an upward path as it does to move it along a level path? Why?

EXTENSIONStudents can calculate the speed at which their rocket balloons travel by dividing thedistance traveled by the time it took.

58


Angle of Flight vs. Distance Traveled

BalloonSize

Distance Traveled

Horizontal 45° 90°

1.

2.

3.

4.

5.

59


INTRODUCTORY STATEMENTThe students will investigate the effects on the rocket balloon’s flight when itsopening is changed.

MATH SKILLSMeasurement-linearMeasurement-anglesGeometry-diameter, circumference


MATERIALSSausage-type balloonsSoda strawsMasking tapeVarious devices to regulate size of opening in balloonsString (monofilament)Measuring tape or meter stickProtractor or clinometerStudent worksheet

KEY QUESTION“How does the size of the opening affect the balloon rocket’s flight?”

BACKGROUND INFORMATION1. We are introducing a new variable here – the size of the opening of the balloon.2. The greater the opening, the faster the air will escape. One question is whether

the increased force of the thrust is great enough to compensate for the shorterlength of time that the air is escaping.

3. Different sized openings can be made by taping short pieces of straw inside theend of the balloons; soda straws, McDonald’s straws, and “cocktail sippingstraws” would give three variations. You might also want to try bent paper clips ifyou watch the sharp ends and roll the mouth of the balloon around the shapecreated. Wine corks which have been sliced thin and had different sized holesmade in them also make good end pieces. Scour the dime store or hardwarestore for small, lightweight plastic rings of various sizes.

60

4. Make sure that students are consistent when they measure the openings;establish that they will measure only the inside diameter of the opening. (If youhave a pair of calipers rusting in the closet, this might be a fun time to bring themout.) Mention “diameter” and “circumference” if you wish.

5. After students have tested their rockets with the five different openings using thehorizontal track, reintroduce the second variable of the angled track. As theangle of the string approaches 90º, perpendicular to the floor, the size of theopening needs to increase to overcome gravitation.

MANAGEMENT1. As before, this activity works best in small groups, with students rotating the jobs.

It will require one to two class periods.2. Have students experiment with fitting end pieces into the mouth of a balloon

before testing as this takes some dexterity. Also, set the standards for measuringthe openings and have students practice.

3. Once the students have established the different “mouthpieces” they are going touse, run the activity using only the horizontal line and recording the variations indistance traveled caused by the difference in openings.

4. Discuss the results from the horizontal test with the students. Have them predictthe results when the line is set at 45° and 90°.

5. Run the last two sections of the test changing both the angles of the line and thecircumference of the opening.

PROCEDURE1. The students will construct rocket balloons as they did before, in parts A and B of

investigation, but they will experiment with creating different-sized, measurableopenings at the mouth of the balloon.

2. When they have established the method of making the openings, have themmeasure the diameter of five, “mouthpieces” of various circumferences andrecord the information of the students worksheet.

3. Have students test each of the five mouthpieces using a horizontal track andrecord the results. Make sure that the balloon used is always the same length.

4. After discussing the results obtained on a horizontal flight, ask students whatthey think will happen on the angled flights.

5. Finally, have students test their rocket balloons using the same mouthpieces,”but on the 45° tracks.

6. Record all data and discuss the results.

WHAT THE STUDENTS WILL DO1. Students will make rocket balloons as before, but will also create end pieces

which will produce five different openings for their rockets.2. Students will test their balloon rockets on the horizontal track using each of the

five “mouthpieces” successively and record the results.3. After discussing the results of that test and predicting what will happen when the

rocket balloons are tested at an angle, students will complete the tests for the45° and 90° tracks.

61

4. Students will complete the student worksheet by filling in the results of thosetests.

5. Comparisons may be among all the charts. What balloon actually went farthest?

DISCUSSION1. What happens if you decrease the size of the opening of the balloon rocket on a

horizontal flight? Why?2. What happens if you decrease the size of the opening of a balloon rocket on an

angled flight? Why?3. How great was the difference in the distance the rockets traveled? What was

the average distance each rocket with the same diameter opening traveled onthe same path?

EXTENSIONIf students are interested, have them add the variable of different balloon lengthsonce again. You can challenge them to design the best rocket balloon for each ofthe three tracks by varying length and size of the opening.

String two parallel lines and run a relay race. Divide the groups into teams. Havethem each mount the first balloon. At the word “Go!”, each team releases its firstrocket, which will go until it stops. It must then be re-blown up and proceed fromthat point. When it reaches the opposite, it must be turned around and startedagain. When the rocket returns to home base, the second balloon replaces it and“flies” the course, and so on. Students will have to decide for themselves which isthe most effective design – opening and length – before the race begins in order toobtain optimum speed and distance in each “heat.”

62


BalloonSize

Size ofBalloonOpening

Distance Traveled

Horizontal 45° 90°

1.

2.

3.

4.

5.

63

EXPERIENCING FORCES

The seven mini-experiments in this exploration provide examples of specific forces atwork. Each one is set up at its own station in the classroom. Your purpose at eachstation is to discover which forces are at work. As you work through the mini-experiments, think about these questions:

What is the agent, receiver, and effect of each force? Are there any new types of forces? How are they different? Are there any non-contact forces—forces exerted by an agent that does not

touch the receiver?Record your observations and conclusions in your Journal.

MATERIALSAn empty jarA pailWaterA glassPaper clips and rubber bandsA magnetA plastic bread bag, cut in stripsA sockHooked massesStringBooksDrinking strawsA bottleNewspaper and cloth towel

OBJECTIVESBy the end of the lesson, students should be able to:1. Identify and classify different types of forces.2. Distinguish between contact and non-contact forces.3. Analyze the forces at work in several new situations.

SCIENCE PROCESSESObservingAnalyzingInferringClassifying

64

STATION ONE

MATERIALSEmpty jar, pail, water

PROCEDURE1. Push the empty jar slowly into a pail of water. Keep its open end facing up.2. Submerge it. Let the water fill the jar.3. Now take the jar out of the water.

What forces do you feel at each step?

Answer: Agent: person’s hand and the water Receiver: the glass Effect: as the empty bottle is pushed into the water, the water exerts an

opposing upward buoyant force upon the bottle. If the bottle is released, it popsupward. As the filled bottle is lifted upward, the opposing downward force (theweight of the bottle and water) is apparent.

New force: buoyant force Non-contact force: none

STATION TWO

MATERIALSMagnet, glass, paper clips

PROCEDURE1. With paper clips under the glass container, bring a strong magnet near the glass

container.2. Try to lift the paper clips to the top of the glass.3. Lift the container off the table.

Think about the forces involved.

Answer: Agent: the magnet Receiver: the paper clip Effect: the magnet, if it is strong enough, attracts the paper clip even though the

glass is between it and the paper clips. These forces are magnetic. New force: magnetic force Non-contact force: magnetic force

65

STATION THREE

MATERIALSScissors, plastic bread bag, wool sock

PROCEDURE1. With one hand, hold up two long strips cut from a plastic bread bag. Observe

them as they hang freely.2. Now Rub both sides of the strips with a wool sock. Allow the strips to hang freely

again. Observe any forces at work.3. Bring one of the strips near the table or wall. What happens?

Identify the force acting on the plastic strips.

Answer: Agent: electrons (static electricity) Receiver: the plastic strips Effect: when the plastic strips are rubbed with a wool sock or piece of fur, they

move apart from each other. Also, the strips tend to be attracted to whateverelse is close by. These pulling and pushing forces, which are exerted at adistance, are electrical.

New force: electrical force Non-contact force: electrical force

STATION FOUR

MATERIALSSeveral sheets of paper

PROCEDURE1. How fast does paper fall? Why does it fall? Try dropping the following:

• A single sheet of paper• A piece folded into quarters• A piece crumpled into a ball

2. Try two different pieces at the same time. Do some fall faster than others?

What are the forces involved here?

Answer: Agent: gravity (the earth) and air resistance Receiver: paper Effect: there is a downward force (gravity) pulling on the pieces of paper. There

is also an upward force (air resistance) pushing on the paper, especially on theuncrumpled piece. The single sheet of paper falls more slowly because of airresistance.

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STATION FIVE

MATERIALSRubber bands, hooked masses, soft object

PROCEDURE1. Hang a hooked mass on the rubber band.2. Add more masses. How many are needed to break the band? Let the masses

drop onto something soft.3. Replace the broken rubber band with a new one so the next person can try the

experiment.

Identify all forces.

Answer: Agent: The masses Receiver: the rubber band Effect: the rubber band is exerting an upward force (elastic) on the weights and

the weights are exerting a downward force (gravity) on the rubber band. New force: none Non-contact force: gravity

STATION SIX

MATERIALSRubber bands, scissors, paper clips, two books, string, drinking straws, metric ruler

PROCEDURE1. Cut a rubber band and tie it securely to a paper clip. Attach the clip to a string

tied around a book and place on a table top. How long must the band stretchbefore the book starts moving?

2. Try it again with another book placed on top of the first one. What do younotice?

3. Place the books on drinking straws and repeat the experiment. How has theopposing force changed? What tends to prevent the books from moving?

Answer: Agent: hand pulling rubber band and rubber band pulling the book Receiver: the book

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Effect: the rubber band applies a pulling force on the rubber band. It takes moreforce to start two books moving than it did for one book. The friction between thebooks and the books and the table opposes the forward motion of the books.The opposing forces of fraction is lessened by the use of the drinking straws.

New force: none Non-contact force: none

STATION SEVEN

MATERIALSBottle, newspaper, cloth towel, board, book, metric ruler

PROCEDURE1. Find out how far a bottle will roll on the floor before stopping.2. Place several sheets of newspaper on the floor and try again.3. Repeat the experiment by rolling the bottle over other surfaces, such as a cloth

towel spread on the floor.

What is slowing down the bottle?

Answer: Agent: gravity (the earth) and the surface of which the bottle rolls Receiver: the bottle Effect: the force of friction opposes the motion of the bottle. The amount of

frictional force depends upon the type of materials over which the bottle rolls. New force: none Non-contact force: none

WHICH FORCES DID YOU MEET IN THE“CARNIVAL OF SCIENCE”?

Water exerted an upward buoyant force on the empty bottle at Station One. Wheredid you see this force before?

A magnetic force was present at Station Two. Did the magnet need to touch thepaper clips to exert an attractive force on them?

An electrical force acted upon the charged plastic strips at Station Three. Whichstrip was exerting force on the other? Is this a non-contact force like the magneticforce?

A gravitational force acted upon the sheets of paper at Station Four. Is this a non-contact force? What agent is exerting the force? Why did the un-crumpled sheetsfall more slowly?

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A stretching or elastic force affected the rubber bands at Stations Five and Six.Where else could you find elastic forces?

Frictional forces were exerted on the bottle and book at Stations Six and Seven. Asan object moves in one direction, frictional forces push the object in the oppositedirection. In what direction was the frictional force at Station Six and Seven acting.

ANSWERS TO WHICH FORCES DID YOU MEET IN THE“CARNIVAL OF SCIENCE”?

1. Floating or swimming are examples of a buoyant force. The sailboat in the storywas kept afloat because of the buoyant force of the water.

2. The magnet does not have to touch the paper clips to attract them. This is anexample of a non-contact force.

3. Each strip exerts a non-contact force on the other. That is, the forces act in pairs.4. The earth exerts a gravitational force that pulls the paper to the ground. It is a non-

contact force, since the earth does not have to touch the paper to exert a pullingforce on it. The un-crumpled sheets fall more slowly due to their larger surfaceareas. The air puts more frictional force on them.

5. Other examples of elastic forces are the ropes and sail being stretched by the windin the story and the elastic forces of the bow acting upon an arrow.

6. Friction acts in a direction opposite to the direction of the motion of an object.

FOLLOW UP

ASSESSMENT1. Ask students to name an example of a buoyant force, an electrical force, a

frictional force, and an elastic force. In each case, ask them to identify the agentand the receiver of the force, and to state what effect the forces has or mighthave on the receiver.

2. What is the most obvious type of force (electrical, frictional, etc) in each situationbelow? Explain your choice.a. A jack in the box (elastic)b. A gymnast on a trampoline (buoyant)c. Deep sea diving (buoyant)d. Parachuting (frictional and gravitational)e. A skier heading down a mountain (gravitational)

EXTENSION1. Have students adjust a faucet so that a very thin stream of water flows from it.

Give a comb a charge by running it through your hair several times. Hold thecomb two or three cm from the stream of water. (The water should be stronglyattracted by the charge of the comb.)

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2. Have students cut a strip of thin cardboard about 2 cm by 10 cm. Fold it in halflengthwise and balance it on a pencil point. The pencil point should indent butnot puncture the paper, so that the paper can turn easily. Put a charger on acomb by running it through your hair. Hold it near one end of the cardboard strip.The cardboard turns on the pencil point and moves toward the comb.

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AssessmentGrade 7

MOTION OF OBJECTS

Classroom Assessment Example SCI.IV.3.MS.1

Small groups of students will set up two identical ramps with distinctly different slopes (onesteep slope and one gradual slope). Before using two identical toy cars, each student will write aprediction about which car will go down the ramp the fastest and which car will go down theramp the farthest. Each student will record his or her hypothesis. The students will take turnsreleasing both cars at the same time. Students will write observations of what happened andexplain reasons why their prediction was correct or incorrect.


Scoring of Classroom Assessment Example SCI.IV.3.MS.1


Accuracy ofhypothesis

Does not write ahypothesis andcontains possiblemisunderstandings.

Provides partialhypothesis withpossiblemisunderstandings.

Provideshypothesis withfew exceptions.

Provides athorough andaccuratehypothesis.

Completenessof conclusions

Does not write acompleteconclusion orconclusion iserroneous.

Writes aconclusion basedon erroneousinformation orcorrectinformation withno details.

Writes aconclusion basedon correctinformation withsome details.

Writes aconclusion basedon correctinformation withmany details.

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Grade Level Standard: 7-4 Compare common forces and motion of objects in

two dimensions.

Grade Level Benchmark: 2. Relate motion of objects to unbalanced forces in

two dimensions. (IV.3.MS.2)


Central Question:How do forces affect the motion of an object?

1. “May The Force Be With You”

2. “The Great Catapult Caper”


Resources

Process Skills: Observing, Predicting, Identifying and controlling variables, Measuring andcomparing, Collecting and recording data, Interpreting data, Inferring

New Vocabulary: changes in motion, friction, gravity, attraction, repulsion,

action/reaction, mass

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MAY THE FORCE BE WITH YOU

INTRODUCTORY STATEMENT:In this group of investigations (May the Force Be With You, May The Force Be With You II, andReturn Of the Force), the students will be isolating variables in order to learn about the energybalance that is in nature.

MATH:AveragingMeasuring - length, massUsing formulaeUsing rational numbers - ratios, percentagesGraphingUsing calculators

SCIENCE:Physical science - simple machines

MATH/SCIENCE PROCESSES:ObservingPredictingIdentifying and controlling variablesMeasuring and comparingCollecting and recording dataInterpreting dataInferring

MATERIALS (per group of five students)2 1/4" diameter x 35" long dowels2 inch ball of clay1 50 cm length of 14 gauge galvanized wire (for catapult)1 25 cm length of 14 gauge galvanized wire (for platform)10-15 wide rim fender washers (washer with small holes but large total diameter ) 1/4" hole with a 1-1/4" diameter2 10 cm x 25 cm pieces of pegboard with 1/4" diameter holespliersbalancemasses - 70 grams1 small empty thread spoolmeter stickchart paper, chalkboard, or overhead projector

KEY QUESTION:What variables affect how high an object will go off the end of a catapult?

BACKGROUND INFORMATION:The First Law of Thermodynamics states that there is an energy balance in nature: energy in =energy out

The potential energy that an object has is its mass x gravity x height (mgh). Mgh is a measure or aunit of energy. In the catapult lesson that follows, the students will do a variety of investigationswhich will lead them to an understanding of mgh. On one side of the catapult, we have the mass(the effort-m) under the force of the gravitational pull of the earth (g) being dropped from a certain

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height (h). By multiplying these three quantities, we have mgh or potential energy on the effort sideof the catapult.

Once the mass is released, the following chain of events takes place in what is called an energybalance:

effort arm resistance armpotential > potential-kinetic > kinetic > kinetic-potential > potential

As the mass is released, the potential energy changes into kinetic energy (the energy of motion)causing the object on the resistance arm (the resistance) to be forced to a certain height on theother side of the catapult.

By manipulating the variables of mass and height, the students will begin to recognize the energybalance in nature. They will discover that the energy going in (mgh of dropped mass) isapproximately equal to the energy going out (mgh of object catapulted). For example: If a 40 gramweight is dropped from a 45 cm height, how high do you have to drop a 50 gram weight in order toforce the resistance to reach approximately the same height as with the 40 gram weight? In thiscase, you know the mass and the height of the effort and you want the height of resistance toremain the same when you are using a different mass. You can calculate mgh = mgh. Because theforce of gravity remains the same (9.82 cm/sec2) whether it is on the potential energy side or thekinetic energy side of the catapult, it cancels itself out. Thus, we are left with mh = mh.

40 g x 45 cm = 50 g x ?40 x 45 = 50 x height

1800 = 50 h1800/50 = h

36 = h

Therefore, a 50 g weight dropped from 36 cm and a 40 g weight dropped from a 45 cm height willforce the resistance to reach approximately the same height. Some error in results will be caused byfriction from the effort or the resistance; the fulcrum, not being the midpoint; leaning dowels;unevenly distributed weights; etc.

Consider the journal story of Mucky Mass. He weighs 300 kg and needs to be lifted six meters. Themass will be dropped from the 3 meter board for a total drop of nine meters. Thus,

? kg x 9 m = 300 kg x 6 mh x 9 = 300 x 6

9h = 1800h = 1800/9

h = 200

Fantastic Force will need to drop at least 300 kg of mass from the diving board.

MANAGEMENT:1. This activity is divided into three parts. In May the Force Be With You, students isolate the

variable of effort’s drop height. In May the Force Be With You II, the students experiment withthe effort’s mass. Return Of the Force has students combine what they know about the effort’smass and height to get the resistance to go a given height.

2. In preparation for teaching the activities, make a catapult for your own experimentation and touse as a model for the students to follow as they build their own.

3. The activities work well with students in groups of five.4. To complete the set of activities requires four to five periods: one period to construct the

catapult system, one period for May the Force Be With You, one period for May the Force Be

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With You II, a fourth period for Part 1 Return Of the Force, and another period for Part 2 ReturnOf the Force.

5. Use 14 gauge wire so the catapult will be sturdy enough to withstand the force of the weights.6. When making the weights, use fender washers and a minimal amount of clay. To economize on

the number of washers necessary for these activities, have the students keep adding washersto make heavier weights (Ex. 30 g = 3 washers, 40 g = 4 washer, etc.).

7. Careful construction of catapults is necessary for the appropriate outcomes of the activities.Stress that the students build the catapults so friction of the masses and the spool are minimal.Be aware that final outcomes are prone to some error due to the simple crudeness of thesystem.

8. To culminate the series of activities on levers, the teacher may want to consider the GreatCatapult Caper which ties together the elements of these force activities and the lever lessons.

PROCEDURE:Construction of the catapults:1. Divide students into groups of five. Distribute the handout Catapult Construction.2. Have students construct the catapults and mark the dowels with lines indicating 5 cm intervals.

Set up the structure using the two pieces of pegboard as a base.3. Brainstorm with the class the variables which they believe will affect the height the resistance

will go. Write the suggested variables on the chalkboard, chart paper, or the overhead projectorto be used later for a discussion of the effects of the individual variables.

ACTIVITY 1: May The Force Be With You1. Discuss the questions: If we drop the same mass (30 g) from different heights onto a catapult,

how will it affect the height the resistance (spool) rises? How could you predict how high thespool will go before you dropped the mass?

2. Distribute and review the activity sheet May the Force Be With You. Explain the procedures ofmaking the weights.

3. Caution students to make certain that they need to hold the dowels straight during the trials.4. Have the students follow the directions, observe and record the results, and complete the

graph.5. As students complete the activity, discuss what relationship exists between the height the effort

was dropped and the height the resistance traveled? (The height of the resistance increased asthe height of the drop increased.)

ACTIVITY 2: May the Force Be With You II1. Ask: What will be the effect on the spool (resistance) when we change the weight but not the

height of the effort in our catapult system?2. Distribute and review the activity sheet May the Force Be With You II.3. Suggest to students that they can use the same washers for the various weights by adding clay

and more washers.4. Have them conduct the trials, then record, average, and graph their results.5. At the completion of the activity, discuss the following questions: What effect did changing the

weight have on the height the spool (resistance) rose? (The heavier weight forced theresistance higher.) Does increasing the weight dropped have the same effect as increasing theheight the mass was dropped? Explain.

ACTIVITY 3: Return Of the Force, Part 11. Discuss how you could determine from what height to drop a weight to get the spool to rise a

given distance.2. Using the catapult equipment, have students take a 30 g weight and drop it so that it causes the

spool to rise to the 40 cm mark on the dowels.3. When the drop consistently gives a 40 cm rise, direct the students to record the height of the

drop.4. Have students calculate the mass x height on the effort arm data.

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5. Repeat steps two to four changing the height of the resistance to 60 cm as indicated on theactivity page.

6. Have students increase the weight of the washers to 10 g , 50 g, 60 g, and 70 g repeating stepstwo to five for each different mass.

7. Have students discuss what pattern they see in the mass x height of the efforts column. (To getthe resistance to rise to a given height, the mass times height of the effort is alwaysapproximately the same.)

ACTIVITY 3: Return Of the Force, Part 21. Have students experiment with the height of the drop needed to get a 30 g weight to raise the

resistance to 50 cm.II. Direct the students to record the drop height needed to make the given rise and calculate the

mass times the height in the first row on the chart.3. Using the mass times the height from the top row of the chart, have the students predict what

height drop will be needed for a 40 g, 50 g, and 60 g weight.4. Allow time for the students to try the different masses to see how close their predictions are to

the actual outcomes and record their results on the chart.5. Have students discuss their conclusions and write a summary statement and formulate.

DISCUSSION:1. What is the relationship between the mass and the height?2. What happens to the height of the effort as you increase the mass of the effort when holding the

resistance constant?3. What is the energy balance that exists?

CURRICULUM CORRELATION:History: Have students research the history of the catapult including the significance of engineers

to the war effort (especially Archimedes). The reports can be done individually or with agroup, oral or written.

MAJOR CONCEPTUAL COMPONENTS: Energy comes in many forms. Mechanical energy is the energy due to the position or the movement of something. Energy cannot be created or destroyed. The amount of energy or work put into a machine will come out of the machine in some form. Energy is used to accomplish work. Work is done when something is moved. The amount of work done is determined by how much force was used to move the object and

how far the object was moved. Levers help to lift loads with less effort. The force needed for lifting changes as the distance of

the effort arm changes.

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THE GREAT CATAPULT CAPER

INTRODUCTORY STATEMENT:Students will apply the information they have learned about catapults and levers in orderto build a high performance catapult.

MATH:AveragingMeasuringUsing formulaeUsing rational numbers ratiosGraphingUsing calculators

SCIENCE:Physical Science - simple machines

MATH/SCIENCE PROCESS SKILLS:ObservingPredictingMeasuringComparingCollecting and recording dataInferringIdentifying and controlling variables

MATERIALS:See Materials and Catapult Construction from May the Force Be With You.

KEY QUESTION:How will you build a catapult to win a high performance catapult contest?

TEACHER BACKGROUND:A lever is a bar that rests on a fixed point called the fulcrum. The force exerted on thelever is called the effort. The object that the lever lifts is called the resistance. Thedistance from the fulcrum to the point where the effort is exerted is called the effort arm.The distance from the fulcrum to the point where the resistance is located is called theresistance arm. The closer the fulcrum is to the resistance, the less effort will be neededto move or lift the resistance. However, this means that the effort must move over a longerdistance while the resistance moves a shorter distance. When the opposite occurs, theeffort arm is closer to the fulcrum than the resistance arm, a greater force will be neededto lift the resistance. In this case, the effort will move a shorter distance while theresistance moves a greater distance.

MANAGEMENT:1. This activity should follow the other lever activities and the series of activities found in

May the Force Be With You.

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2. This activity can be assigned as homework and brought back to class for thecompetition, or it could be assigned as class work with students working in groups todesign their catapults.

3. A class graph can be made on chart paper or drawn on the chalkboard. Atransparency of the student Worksheet could also be used for collecting class data.

4. Each group or individual will need only 50 grams of weight.

PROCEDURE:1. Have students make catapults using procedures similar to May the Force Be With

You. In this activity, they should be experimenting with different fulcrum points in orderto attain maximum results. Fifty (50) grams of weight will be held constant for theeffort.

2. Instruct students to select their most successful designs and name their catapultentries.

3. Conduct the competition.4. Gather and record data of class results.5. Have students complete the graph.

DISCUSSION:1. Was there any relationship in the length of the resistance arms or effort arms and the

rankings? Explain.2. What were some of the reasons that certain catapults worked better than others?

EXTENSIONS:What is the lightest weight that must be dropped on the effort side in order for theresistance to be forced off the dowel? From what height must it be dropped? Could weuse the mgh formula that we used in the previous lessons to help us discover this?

MAJOR CONCEPTUAL COMPONENTS: Energy comes in many forms. Mechanical energy is the energy due to the position or movement of something. Energy cannot be created or destroyed. The amount of energy or work put into a machine will come out of the machine in

some form. Energy is used to accomplish work. Work is done when something is moved. The amount of work done is determined by how much force was used to move the

object and how far the object was moved. Levers help to lift loads with less effort. The force needed for lifting changes as the

distance of the effort arm changes.

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AssessmentGrade 7

MOTION OF OBJECTS


Each student will draw a picture of two teams of students playing tug-of-war. Using the words“balanced forces,” “unbalanced forces,” and “motion,” each student will write an explanation ofwhat happens when the tug-of-war teams both pull away from each other but there is nomovement. Students should use arrows on the diagram to represent the forces of both teams. Thestronger force should be represented by a larger arrow. Using the words “balanced forces,”“unbalanced forces,” and “motion,” each student will write an explanation of what needs tohappen for one team to be the winner of the tug-of-war.




Accuracy ofdescription -forces in nomovementsituation

Identifies nobalanced forcesand incorrectly orincompletelydraws forcearrows ondiagram.

Identifies both ofthe balancedforces andincorrectly orincompletelydraws forcearrows ondiagram.

Identifies bothbalanced forcesand correctlydraws forcearrows ondiagram.

Provides clear andcompleteidentification ofbalanced forcesand correctlydraws force arrowson diagram.

Accuracy ofdescription -forces inwinningsituation

Identifies none ofthe unbalancedforces andincorrectly orincompletelydraws forcearrows ondiagram.

Identifies both ofthe unbalancedforces andincorrectly orincompletelydraws forcearrows ondiagram.

Identifies both ofthe unbalancedforces andcorrectly drawsforce arrows ondiagram.

Provides clear andcompleteidentification ofunbalanced forcesand correctlydraws force arrowson diagram.

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Grade Level Standard: 7-4 Compare common forces and motion of objects in

two dimensions.

Grade Level Benchmark: 3. Design strategies for moving objects by application of

forces, including the use of simple machines. (IV.3.MS.5)


Central Question:How can we control the motion of objects?

1. Newton’s three laws with experiments/observations.

2. “Making a Steam Power Rocket Boat”


Resources

Seehttp://www.reachoutmichigan.org/

and

http://www.ed.uri.edu/SMART96/ELEMSC/SMARTmachines/machine.html

Process Skills:

New Vocabulary: levers, pulley, screw, inclined plane, wedge, wheel and axle,

gear

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NEWTON’S FIRST LAW OF MOTIONActivity

PURPOSETo demonstrate Newton’s First Law of Motion

MATERIALSPer person or group of 2:

1 paper or plastic cup1 marbleA table top

DIRECTIONSFIRST PROCEDURE:

1. Place the cup on its side on the table.2. Put the marble in the cup.3. Grasp the cup in your right hand making sure the open end of the cup is

facing left.4. Quickly move the cup to your right along the table top.

SECOND PROCEDURE:1. Place the cup on its side on the table.2. Put the marble in the cup.3. Grasp the cup in your right hand with the open end of the cup facing left.4. Quickly move the cup to the left along the table top.

QUESTIONS1. What happened to the marble in the first procedure?

________________________________________________________________

________________________________________________________________

2. What happened to the marble in the second procedure?________________________________________________________________

________________________________________________________________

3. How is Newton’s First Law of Motion demonstrated in each of these twoprocedures?________________________________________________________________

________________________________________________________________

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NEWTON’S SECOND LAW OF MOTIONActivity

PURPOSETo demonstrate Newton’s Second Law of Motion by propelling a projectile with a“slingshot” launcher.

MATERIALS1. 1 wooden block (2 by 4 stock that is 16 cm long) with three nails pounded in; two

nails at one end have heads, and one at the other end is a finishing nail. Seediagram for making slingshot.

2. 1 small container like a covered film canister and 20 pennies.

3. 1 rubber band around 6 cm in diameter.

4. 1 meter stick or tape measure.

5. Safety glasses for each student.

DIRECTIONS1. Secure wooden block at one end of your lab table with a clamp or tape.

2. Loop a rubber band over the 2 heads with nails.

3. Next, stretch both bands over the finishing nail “trigger” that has no head.

4. Place the covered film canister with no pennies in the slingshot.

5. Shoot the slingshot by releasing the rubber band and record the distance theprojectile moves.

6. Repeat 4 and 5 over and over, but increase the mass of the covered canister byone penny each trial.

7. Make a table to display your data.

8. Display the data on your data table.

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QUESTIONS1. Explain what you observed?

________________________________________________________________

________________________________________________________________

2. What is Newton’s Second Law of Motion?________________________________________________________________

________________________________________________________________

3. How does this activity demonstrate Newton’s Second Law of Motion?________________________________________________________________

________________________________________________________________

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NEWTON’S THIRD LAW OF MOTIONActivity

PURPOSETo demonstrate how rocket liftoff is related to Newton’sThird Law of Motion.

MATERIALSOne sheet heavy paper (60-110 stock), 8 ½ x 11Clear Plastic 35 mm film canister with internal sealing lid

(Fuji, Scotch brands)Cellophane (clear) tapeScissors½ Antacid Tablet (Alka-seltzer) ½ tablet per launchPaper towelWaterSafety glasses

DIRECTIONS1. Cut 1/4 of the paper off end and set aside to use for the cone and fins.

2. Roll the 3/4 piece of paper into a cylinder around the film canister. Make surethe top of the canister is sticking out below the paper. Tape the cylinder directlyto the canister.

3. Cut the 1/4 piece of paper in half, and roll one half into a cone and tape it to thetop of the paper cylinder which is at the opposite end of the canister.

4. With the remaining piece of paper, make four fins for the rocket and tape them tothe end of the canister, but do not let them extend beyond the canisters lid.Make sure the rocket can set upright without falling over.

5. Remove the canister lid and fill the canister half full of water.

6. Drop ½ an antacid tablet into the canister and secure the lid.

7. Set the rocket upright on a piece of paper towel on a level surface.

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QUESTIONS1. What did you observe and explain why it happens?

________________________________________________________________

________________________________________________________________

2. How does this activity relate to Newton’s Third Law of Motion?________________________________________________________________

________________________________________________________________

3. Does the amount of water in the canister have any effect on how high the rocketwill go?________________________________________________________________

________________________________________________________________

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Energy and Science Projects

For Students

MAKING A STEAM-POWERED "ROCKET BOAT"

WHAT YOU'LL NEED

Metal tube (a cigar tube works great -- ask an adult to get you one)

Two pieces of strong, stiff wire (like clothes hanger wire) about 18-inches long

Cork that fits snugly into the end of the tube

Two food warmer candles (in metal cups)

Balsa wood (4 inch by 8 inch, ½-inch thick)

Masking tape

Hammer and three nails

Matches

You'll need an adult's help with the matches and the hammer and nails!

WHAT TO DO

1. Put the cork into the end of the metal tube making sure its very tight. Carefully poke ahole through the cork with a nail.

2. Take the two 18-inch lengths of wire. Wrap the wire around metal tube about one-inchfrom each end of the tube, and twist the wiretightly with the pliers so the tube is firmly held bythe wire and won't slide

3. Cut a boat shape out of the balsa wood, making atriangle bow an one end. Hammer two large nailsin each end about one inch in from each end. Thenails will help to stabilize.

4. Mount the two candles about 1-1/2 inches fromeach end of the wood. Use loops of masking tapeto stick the metal cups to the wood.

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5. Take the tube with the wire and mount the tube so the wire will hold the tube just abovethe candles. Wrap the ends of the wire around and under the board and twist the endsneatly on the underside. (See picture.)

6. Carefully remove the cork from the tube and fill the tube about three-quarters full withvery hot water. Tightly replace the cork. Make sure water will drip out the hole in thetube.

7. Fill up a bath tub or a large sink with water.

8. Put your boat in the water and ask an adult to carefully light the candles.

RESULTS

The heat of the candle will cause the water in the tube toboil. The water will change to steam and the steam willescape out the hole in the cork pushing the boat forward inthe water.

Here are some questions to think about:

Why use hot water in the tube?

What would happen if you used cold water?

What would happen if you didn't put a hole in the cork?(DON'T TRY THIS!)

What would happen if the hole in the cork were larger

WHAT'S HAPPENING

There are two different things to learn here.

The first is what makes rockets fly off into space. It's a law of physics that says "for everyaction there is an equal and opposite reaction." What this means is that the steam escapingout the hole in the cork is an action in one direction. The reaction is that the escaping steamwill push the boat forward.

A rocket works the same way. Hot gases and fire come out of the motor of a rocket. Thegases coming out the nozzle at the bottom of the rocket come out in one direction. Theseescaping gases push the rocket in the opposite direction.

Second, energy from the candles changes the water into a gas (water vapor or steam). Thesteam can escape Steam is used in a lot of energy power plants.

This Energy Education Project comes from the California Energy Commission

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AssessmentGrade 7

MOTION OF OBJECTS


The following assessment can be used at the end of the pulley section of the simple machine unit.

The teacher will read the following scenario to the class:

A man has fallen into a deep hole with slippery sides. He has tried but cannot climb out. Beforefalling into the hole, he left a long rope, two fixed pulleys, and two movable pulleys on theground above. Traveling with the man was his small son. The man can shout directions to hisson but his son cannot pull him out or run for help. There are no ladders or anyone else to help.The only way out is to use the pulleys and rope.

Each student will write out directions that explain to the son what to do in order to get the manout of the hole and will draw a picture of the procedure to get the man out of the hole.




Completeness ofdirections

Writes fewdirections with nodetails.

Writes most stepsof the directionsin correct orderusing pulleys andincluding a fewdetails.

Writes step-by-step directions incorrect orderusing pulleys andincluding somedetails.

Writes step-by-step directions incorrect orderusing pulleys andincluding manydetails.

Completeness ofdiagram

Draws a partialdiagram with nolabels.

Draws a diagramwith mostinformationcorrect and a fewlabels.

Draws a diagramthat includes theproper set-up anduse of pulleyswith some labels.

Draws a diagramthat includes theproper set-up anduse of pulleyswith all labels.

Documents

Life Science Worksheet - · PDF file1 Life Science Worksheet GRADE LEVEL: Seventh Topic: Organization of Living Things Grade Level Standard: 7-1 Compare and contrast living things