CURRICULUM GUIDE: LEAVES · Maybe you could prepare a photo essay. Root Words Vivid fall colors of...

Volume 1, I s sue 6

© 2001 The Washington Post Company

CURRICULUM GUIDE: LEAVES

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Washington

PostNewspaperInEducationProgram

An Integrated CurriculumResource Program

KLMNO

Leaf Resources

A look at the lifecycle of a leaf

Evaluating DescriptiveWriting

Writing Descriptions

On writing about a tree on a tree—get out your journal

Word Study

The FUNdamentals of photosynthesis.

The Three Pigments

How leaves showtheir true colors.2 6Academic ContentStandards8

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ABCDE][

IN THIS ISSUE

Oct. 23, 2001

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An Integrated Curriculum For The Washington Post Newspaper In Education Program

Volume 1, I s sue 6 Oct. 23, 2001KLMNO


Lesson: An introduction to photosynthesis and the life cycle of a leaf.

Level: Grades 3-6

Subjects: Science, English Language Arts

Related Activity: Art

Procedure

Read

Read the KidsPost articles.

Examine and DiscussAsk students to answer the following questions. Discuss the answerswith particular attention to their understanding of photosynthesis.

1. What is the most visible change to leaves of deciduous trees in thefall?

2. What does chlorophyll do to help photosynthesis take place?

3. What are nutrients?

4. Photosynthesis is a process. What happens during photosynthesis?

5. It is helpful that leaves fall off tree branches before winter arrives.

Explain why.

6. Which is the dominant pigment in most leaves?

7. What gives fall leaves their yellow color?

8. List three vegetables that have the carotenoid dominant pigment.

9. What gives fall leaves their red color?

10. How do anthocyanins and carotenoids protect trees?

Read For InformationGive students copies of "Three Pigments." Read to learn more aboutchlorophyll, anthocyanins and carotenoids. Be sure studentsunderstand that the three pigments are found in flowers, plants, fruitsand vegetables as well as leaves. Distinguish the three pigments fromone another.

Observe and Write Ask students to observe a tree or a group of trees for five days. Theyare to record their observations in a journal. While observing theymay write phrases, make lists, record dialogue, sketch the scene and

Leaves ResourcesOn the Web and in PrintON THE WEBShedding Light on Photosynthesis

If you want to do more than collect fall's leaves, placethem between sheets of wax paper and iron them topreserve them, check these sites for ideas.

http://photoscience.la.asu.edu/photosyn/educa-tion/colorchange.html

Why Do Leaves Change Color in Fall?

Science Made Simple provides this site for children.Includes an elementary, large type version to downloadfor the youngest readers. This site includes three proj-ects that adults can do with children: Separate Colors ina Green Leaf Using Chromatography, Separate Colorsin a Fall Leaf Using Chromatography and ObserveHow Light Affects Color Development.

http://www.pbs.org/ktca/newtons/9/phytosy.html

Photosynthesis: How Do Plants Make Food?

To accompany Newton's Apple show number 907, youwill find a short lesson, questions, activities and vocabu-lary. You need not have seen the show to use this mate-rial.

http://photoscience.la.asu.edu/photosyn/educa-tion/photointro.html

An Introduction to Photosynthesis and Its Applications

A resource from the Arizona State University Centerfor the Study of Early Events in Photosynthesis forteachers who want the review the basics. Illustrationsare helpful.

http://www.accessexcellence.org/AE/AEC/AEF/1996/morishita_pictures.html

Photosynthetic Pictures Are Worth More Than aThousand Words

In this Access Excellence Activities Exchange, C. FordMorishita provides background, materials and all stepsto follow in this experiment. This is one for olderstudents or one for teachers to demonstrate for (andamaze) their students.

IN PRINTGardiner, John Reynolds. Top Secret.Education World recommends this fourth-grade levelbook. In it, a science fair project inspires a boy to solvethe mystery of photosynthesis.

Learn About LeavesKidsPost Article: "Fall Guys: Colorful Show Signals The Approachof Winter"

3 © 2001 The Washington Post Company

write in complete sentences. Ask that each day they view the tree fromdifferent perspectives. For example, they might sit at a distance south ofthe tree one day, under the tree on another day. Tell students that theyare not to climb the tree.They may include people in their descriptions, especially if theindividuals are raking leaves.

Either as homework or an in-class activity, students are to use theirobservation notes to write one to three paragraphs in which theydescribe the tree. They are to include enough sensory details anddescriptions so that others can picture the scene. On one of the five days,they should include information from the KidsPost article and "ThreePigments" handout. They may also research to learn more about thespecies they are observing.

At the end of five days, students are to review their journal entries anddescriptive paragraphs. Select one of the five days' descriptiveparagraphs to revise. Tell them this will be shared with their classmates.

Share and EvaluatePair students to share their revised descriptive paragraphs. Ask eachstudent to evaluate the work of his or her partner's descriptive writing.You may wish to use the "Descriptive Writing Evaluation" reproducible.

Decide and Revise Students decide which of the suggestions to include in their descriptiveparagraphs. They make spelling, punctuation and grammar corrections.

PublishStudents may print their descriptive piece on large sheets of paper in theshape of a leaf, print on paper which is the color of fall or word processand print out. Teachers may wish to "publish" the descriptiveparagraphs on a display board with leaves that students have preserved.

"Fall Guys: Colorful Show Signals The Approach of Winter" can befound at http//www.washingtonpost.com/

Enrichment 1. Conduct one of the experiments that are described in the Webresources.

2. Ask students to make a leaf collection in which they must collect 6-10leaves from different trees and identify the leaves. Explain ways topreserve and present the leaf collections.

Learn About LeavesContinued

ON THE WEB

http://www.state.me.us/doc/foliage/kids/index.html

Maine Foliage Kids' PageMaine was the first state to post weeklyfoliage reports on the Web. "Maine TreeGuide" provides a list of native conifers andbroadleaf trees and a guide to foliage speciesthat you can download for students to color.Glossary and Forest facts are good resources.Do take time to view "How the LeavesChange Color."

http://www.ces.ncsu.edu/nreos/forest/topics/leafco~1.html

Why Leaves Change ColorA useful graphic and overview provided byNorth Carolina Cooperative ExtensionService.

http://virtual.clemson.edu/groups/FieldOps/Cgs/leaves.htm

Why Do Leaves Change Color?In addition to basics of leaf chemistry andtrees by dominant coloring, the Clemson siteprovides methods for collecting andpreserving leaves.

http://scifun.chem.wisc.edu/chemweek/fallcolr/fallcolr.html

The Chemistry of Autumn ColorsScifun gives the scientific perspective as seenby a chemist.

http://nl4.newsbank.com/nl-search/we/Archives?p_action=doc&p_docid=0EF25A916E90BA84&p_docnum=75&s_subterm=Subscription%20until%3A%2012%2F31%2F2010%2023%3A59%3A59&s_subexpires=12%2F31%2F2010%2023%3A59%3A59

It's the Maine Attraction for Woodcock andGrouseA very different take on Maine's foliage,forests and hunting. For older students.



4 © 2001 The Washington Post Company

1. I think your central idea is:

2. Strengths of your descriptive writing

a. I can see:

b. I can hear:

c. I can almost feel:

d. The best sensory detail is:

3. Recommendations for improvement

a. Your description of ________________________ could be stronger if you:

b. I think your description would be stronger if you:

4. I have circled mistakes in spelling, punctuation and grammar

Signature of student evaluator

_______________________________

Descriptive Writing Evaluation

NAME ____________________________________________________________________




5

Think of leaves as the kitchen of the tree, the placewhere food is prepared. The food is sugar and starchthat's produced by taking a gas called carbon dioxideout of the air, combining it with water from theground and using a special process to create exactlywhat the tree needs to survive and grow. That specialprocess is called photosynthesis, and it depends ontwo things: sunlight and chlorophyll.

Sunlight provides the “heat” to make “cooking”possible. Without light, plants cannot make food. Iffood is not made, cells of the plant can die.

Chlorophyll [pronounced CLOR-o-fill] is a chemicalthat takes energy from sunlight and turns it into treefood. It’s not surprising that chlorophyll is green. TheGreek word for the color green is chloro.

Let’s take a closer look at “photosynthesis.” It iscomposed of three Greek words: Phot and phos,meaning light + syn, meaning with + thesis, meaningposition. So “photosynthesis” conveys the idea ofbeing in a place with light.

Here’s another way of looking at photosynthesis.

Photosynthesis is a process. During this action,plants use the energy from sunlight to produce sugar.Cellular respiration converts the sugar into ATP, the“fuel” used by all living things. The conversion ofunusable sunlight energy into usable chemical energyreceives the actions of the green pigment chlorophyll.You need photosynthesis to stay alive. Don’t forgetyou need those green vegetables, too.

Here is the way a chemist describes photosynthesis:

6H2O + 6CO2 ———> C6H12O6+ 6O2

This expression explains what happens when sixmolecules of water are added to six molecules ofcarbon dioxide. Together they produce one moleculeof sugar and have six molecules of oxygen left over.So, you can have your sweets and breathe too.

Word Study: A look at photosynthesis

We have studied photosynthesis. What other word isformed from the Greek word for light?

Want to make a collection of this fall’s leaves? Youcould gather leaves and place them between papertowels with stacks of books on top of them to drythem out. You could draw them with crayons orpaint them with watercolors. You could take acolor photograph.

What is a photograph? You know what photomeans. Light.

What does graph mean?

Graph comes from the Greek word graphikos thatmeans writing and the verb graphein that means towrite. So when you take a picture you are writingwith light.

Maybe you could prepare a photo essay.

Root Words

Vivid fall colors of maple tree leaves brighten the walk home fromschool for a high school student in Huntsville, Ala.

AP PHOTO /HUNTSVILLE TIMES, GLENN BAESKE

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ILLUSTRATION BY PATTERSON CLARK—THE WASHINGTON POST

More than a Pretty Color: Three Pigments

1. AnthocyaninsWhat is the etymology ofanthocyanin? Two Greek words:antho, meaning plant + cyan,meaning blue

What color do anthocyanins provide?Anthocyanins give plants theircolor. The colors have a wide range:salmon-pink, red, crimson, blue,purple

Where can I find anthocyanins?Fruits: blueberry, cherry, Concordgrape, cranberry, raspberryLeaves: red maple, red oak, sumacPlants: bromeliads, carnivorousplantsVegetables: carrot, red cabbage

What do anthocyanins do?■ Anthocyanins are pigments thatprovide color. Anthocyanins arenatural colorants that are found inmany flowers, fruits and vegetables.They belong to a group ofcompounds called the flavonoids.

■ Anthocyanins help plants.Anthocyanins attract insects for thepurpose of pollination. Thesepigments also play a major role inpredation in carnivorous plants by

attracting insects into the trapapparatus. Anthocyanin-relatedpigments are produced in responseto exposure of the plant to UVradiation, They become a screen toprotect the plant's DNA fromdamage by sunlight. In a lesssignificant role, anthocyanins serveas anti-feedents. Animals don't liketheir taste so they don't eat theplants.

■ Anthocyanins are antioxidants.You should eat fruits and vegetableshigh in anthocyanins againstcardiovascular and other diseases.s

What are scientists asking?Are anthocyanins able to inhibitLDL (the "bad") cholesterol,prevent blood clotting and defendcells against dangerouscarcinogens?Learn moreaboutanthocyanins

http://www.nal.usda.gov/ttic/tektran/data/000007/19/0000071970.html

Anthocyanins: Natural Colorants with PotentAntioxidant Properties

http://www.pittstate.edu/chem/courses/chem326b/chromo.html

Anthocyanins and Thin-layered Chromatography

Lab procedure to chromatograph plant extracts isprovided. Advanced level, but provides teacherswith background information.

2. CarotenoidsWhat is the etymology of carotenoid?The Greek word karoton and Latinword carota, meaning carrot + theGreek suffix eidos, shape or form.The emphasis is on the color of thepigment.

What color do carotenoids provide?Carotenoids give color to plants andanimals. These pigments give foodstheir orange-red colors and flowerstheir yellow colors. The colors havea wide range: yellow, orange,orange-red

Where can I find carotenoids?Animals: cardinal, flamingo,goldfishFruits: orange, peach

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ILLUSTRATION BY PATTERSON CLARK—THE WASHINGTON POST

Leaves: birch, cottonwoodVegetables: corn, carrot, kale,spinach, turnip

What do carotenoids do?■ Carotenoids are pigments thatprovide color.A scientist named Berzelius in 1837named the yellow pigments ofautumn leaves xanthophylls. Theyare carotenoids.

■ Carotenoids are antioxidants.Oxidation is a kind of theft. Thechemical thieves are called agents,oxidizing agents. They rob atoms,molecules and ions of one or moreelectrons. When oxygen is anoxidizing agent, you can see it. Theapple turns brown, the iron nailrusts and your blue jeans fade.In humans, carotenoids protect cellsand tissues by acting as biologicalpolice to stop the theft. Forexample, xanthophylls found in cornand spinach are believed to protectthe macular region of the retina.■ Carotenoids are essential inphotosynthesis.Carotenoids provide vitamin A.

Have you heard of beta-carotene? Itis a main source of vitamin A thatyou need to remain healthy. If youdon't have enough vitamin A whenyou are young, you can become

sick. Some children in very poorcountries (developing nations) donot receive necessary vitamin A sothey die young.

What are scientists asking?Do carotenoids help in the fightagainst cancer, heart disease anddegenerative eye disease? See whatyou can find out about recentresearch. The USDA even has aCarotenoids Research Unit at itsBeltsville Human NutritionResearch Center(http://www.barc.usda.gov/bhnrc/bhnrc.html).Learn more about carotenoidshttp://dcb-carot.unibe.ch/carot-intro.htmThe Carotenoids Page

http://www.cc.nih.gov/ccc/supplements/vita.htmlVitamin A and Carotenoids

3. ChlorophyllWhat is the etymology ofchlorophyll? Two Greekwords: chloro,meaning green +phyll, fromphullon,meaning leaf.

What color does chlorophyll provide?Chlorophyll provides the greencolor of leaves.

Where can I find chlorophyll?In green leaves. The chlorophyll inleaves decays in autumn. The greencolor fades so that the anthocyaninsand carotenoids can be seen.

What does chlorophyll do?Chlorophyll is a hard worker that isessential for photosynthesis to takeplace. Chlorophyll collects sunlight.It changes the energy of sunlightinto an energy that can combinecarbon dioxide (something that isnot good for humans to breathe) andwater. The result is a good product, acarbohydrate. Photosynthesis keepsplants alive. Since we eat plants andanimals eat plants, chlorophyll isvery important to our life.

Learn more about chlorophyllhttp://scifun.chem.wisc.edu/chemweek/chlrphyl/chlrphyl.htmlChemical of the Week: Chlorophyll

A quick overview of the chemical properties ofchlorophyll; for teachers.http://www.chm.bris.ac.uk/motm/chlorophyll/chloro

phyll_h.htmChlorophyll

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Academic Content StandardsThis lesson addresses academic content standards of Maryland, Virginia and the District ofColumbia. Among those that apply are:The main lesson addresses these academic content standards of:

MarylandScienceLife Science (3.0): Students will usescientific skills and processes toexplain the dynamic nature of livingthings, their interactions and theresults from the interactions thatoccur over time. Biochemistry: Bythe end of grade 3, students knowand are able to: 3.3.12 explain thathabitats provide basic needs, (i.e.,food, water, shelter, energy) for theorganisms living in them. Ecology:By the end of grade 3, studentsknow and are able to: 3.3.12 explainthat habitats provide basic needs,(i.e., food, water, shelter, energy) forthe organisms living in them. By theend of grade 5, students know andare able to: 3.5.12 cite evidence thatindividuals and groups oforganisms interact with each otherand their environment.

Environmental Science (6.0):Students use scientific skills andprocesses to investigate theinterrelationships of the naturalworld and to analyze environmentalissues and their solutions.Interdependence of Organisms: By theend of grade 8, students know and areable to: 6.8.2 identify and explain theinterdependency of organisms withinthe environment in a given ecosystem(i.e., producer/consumer,predator/prey, host/parasite).

Language ArtsWriting (3.0): Students produceinformational, practical, persuasiveand narrative writing thatdemonstrates an awareness ofaudience, purpose and form usingstages of the writing process asneeded (i.e., pre-writing, drafting,revising, editing and publishing).

A complete list of State Content Standards ofMaryland can be found athttp://www.mdk12.org/mspp/standards/.

VirginiaScienceLife Processes, Grade 4, 4.4: Thestudent will investigate andunderstand basic plant anatomyand life processes. Key conceptsinclude photosynthesis(chlorophyll, carbon dioxide) anddormancy. Grade 7, LS.6: Thestudent will investigate andunderstand the basic physical andchemical processes ofphotosynthesis and its importanceto plant and animal life. Keyconcepts include

■ energy transfer between sunlightand chlorophyll;■ transformation of water andcarbon dioxide into sugar, waterand oxygen; and■ photosynthesis as the foundationof food webs.EnglishWriting, Grade 3, 3.7: The studentwill write descriptive paragraphs.

■ Develop a plan for writing■ Focus on a central idea■ Group related ideas■ Include descriptive details thatelaborate the central ideaGrade 6, 6.7: The student willwrite narratives, descriptions andexplanations.■ Use a variety of planningstrategies to generate and organizeideas.■ Establish central idea,organization, elaboration andunity.■ Select vocabulary andinformation to enhance the centralidea, tone and voice.A complete list of Standards of Learning ofVirginia can be found on the Webat http://www.pen.k12.va.us/.

Washington, D.C.ScienceLife Science, Content Standard 2:Observe, investigate, describe andclassify living things; explain lifecycles, diversity, adaptations,structure and function of cells andsystems reproduction, heredity,interdependence, behavior, flow ofenergy and matter and changesover time. By the end of grade 3,the student will describe life cyclesof familiar organisms; produceevidence to explain that somesource of energy is needed for allorganisms to stay alive and grow.

EnglishLanguage as Literature, ContentStandard 2: Students respond inmany ways to a rich variety ofliterary texts and relate texts to life.Grade 3: The student connectsfacts, incidents and details asappropriate; writes topic sentences,supporting details and concludingsentences; excludes extraneousdetails and inconsistencies;evaluates writing against specificcriteria and revises text to meet thestandard; writes responses in atleast three paragraphs.

A complete list of Standards for Teaching andLearning of the District of Columbia PublicSchools can be found athttp://www.k12.dc.us/.

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