AGC/United Learning 1560 Sherman Ave., Suite 100 Evanston, IL Photosynthesis. Grades 5-8. Teacher's Guide

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AGC/United Learning • 1560 Sherman Ave., Suite 100 • Evanston, IL 60201 • 800-323-9084

Photosynthesis

Grades 5 - 8

Teacher's Guide

Written and Produced by

John Colgren and Paul Fuqua

AGC/United Learning

1560 Sherman Avenue, Suite 100

Evanston, Illinois 60201

(800) 323-9084, Fax (847) 328-6706

http://www.agcunitedlearning.com

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This video is the exclusive property of the copyright holder. Copying, transmitting, or reproducing in any form, or by any means, without prior written permission from the copyright holder is prohibited (Title 17, U.S. Code Sections 501 and 506).

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Photosynthesis

Table of Contents

Introduction ... 1

Instructional Notes ... 1

Links to Curriculum Standards ... 1

Student Objectives ... 2

Assessment Tools ... 2

Teacher Preparation ... 2

Introducing the Video ... 2

View the Video ... 3

Discussion Questions ... 3

Blackline Master Descriptions ... 3

Enrichment Activities ... 4

Answer Key ... 4

Internet Resources ... 6

Script of Video Presentation ... 7

This video is closed captioned

The purchase of this video program entitles the user to the right to reproduce or duplicate, in whole or in part, this teacher's guide and the blackline master handouts that accompany it for the pur-pose of teaching in conjunction with this video, Photosynthesis. This right is restricted only for use with this video program. Any repro-duction or duplication in whole or in part of this guide and the black-line master handouts for any purpose other than for use with this

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PHOTOSYNTHESIS

GRADE LEVELS: 5 - 8

This lesson is designed for use in grades 5 - 8 as an introduction to the major ideas and concepts associated with the food making process known as photosynthesis. Only plants are capable of making their own food. In fact, as humans, all food on which we depend can be traced back to the plant world. In addition, plants release oxygen into the atmosphere as a by-product of photosynthesis. Thus, for two very important needs we owe a debt to the plant world.

INSTRUCTIONAL NOTES

Before presenting these lessons to your students, we suggest that you pre-view the video and repre-view this guide and the accompanying blackline master activities in order to familiarize yourself with their content.

As you review the materials presented in this guide, you may find it neces-sary to make some changes, additions, or deletions to meet the specific needs of your class. We encourage you to do so, for only by tailoring this program to your class will they obtain the maximum instructional benefits afforded by the materials.

It is also suggested that the video presentation take place before the en-tire group under your supervision. The lesson activities grow out of the con-text of the video; therefore, the presentation should be a common expe-rience for all students.

LINKS TO CURRICULUM STANDARDS

As stated in the the National Science Education Standards, "In the middle-school years, students should progress from studying life science from the point of view of individual organisms to recogninizing patterns in ecosys-tems." The specific content standards addressed in this lesson are: • A population consists of all individuals of a species that occur together at a given place and time. All populations living together and the physi-cal factors with which they interact compose an ecosystem.

• Populations of organisms can be categorized by the function they serve in an ecosystem.

• For ecosystems, the major source of energy is sunlight. Energy entering ecosystems as sunlight is transferred by producers (plants) into chemical energy through photosynthesis. This energy then passes from organism to organism in food webs.

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STUDENT OBJECTIVES

After viewing the video and participating in the follow-up activities, stu-dents/participants should be able to...

• Identify photosynthesis as the food-making process used by green plants.

• Describe the important contributions to survival on earth green plants provide through photosynthesis and the releasing of oxygen into the atmosphere.

• Identify the necessary materials needed for photosynthesis to take place.

• Identify the fossil fuels and describe their link to energy from the sun and plants that lived millions of years ago.

ASSESSMENT TOOLS

This lesson provides you with three different assessment tools. Together they make it possible to closely follow the progress of your students and to judge their mastery of the subject matter it covers.

The Pre-Test (Blackline Master #1) can be used to get some idea of stu-dents' understanding of the topic before the video is presented.

The Post-Test, presented as Blackline Master #7, can be used as a final test for this Unit of Study.

The Video Quiz and its accompanying answer sheet (Blackline Master #2) can be used either as a way to introduce the topic prior to showing the video or to judge student mastery once the video has been presented.

TEACHER PREPARATION

View the video and review the accompanying activities. Duplicate any blackline masters you wish to distribute. If you plan to use the Video Quiz, which immediately follows the video presentation, you may wish to have copies of the quiz ready to distribute at the completion of the video pro-gram. Also, plan to pause the tape between questions if students require more time.

INTRODUCING THE VIDEO

This videotape is about the food-making process known as photosynthe-sis. Green plants use photosynthesis to manufacture their food. During the process carbon dioxide, water, and energy from the sun combine to form glucose, a form of sugar used by the plant as food. This only occurs in green plants that contain a chemical called chlorophyll. As a by-product of photosynthesis oxygen is released into the air. Green plants are respon-sible for releasing oxygen and as a result replenishing the earth's supply of oxygen.

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VIEW THE VIDEO

Viewing Time is 10 minutes for the program and about 5 minutes for the Video Quiz.

DISCUSSION QUESTIONS

1. Discuss the relationship plants and animals share. What is it that plants need from animals and what do plants produce that is essential to ani-mals?

2. Reinforce the importance of green plants to all life on earth. Trace different foods back to plants. Also, all forms of energy on earth such as fuels are traceable to plants and the energy of the sun.

3. Why will space missions to distant planets require the transportation and inclusion of green plants.

BLACKLINE MASTER DESCRIPTIONS

This program contains seven blackline masters that can be used to rein-force ideas and information presented in the video. Answers to Blackline Master activities appear on pages 4-6 of this guide.

• Blackline Master #1: Pre-Test provides a way of finding out how much students know about the material covered in this lesson before you present it. Student scores on the pre-test can be compared with their scores on the final Post-Test (Blackline Master #7).

• Blackline Master #2: Video Quiz is to be used at the end of the video program. At the completion of the video, there is a short quiz. The narrator will read the questions which are displayed on the screen. Stu-dents can use Blackline Master #2: Video Quiz to record their answers. • Blackline Master #3: Crossword is both a crossword puzzle and a fill-in assignment. Students will read the paragraph at the bottom of the page and place the missing words in the crossword.

• Blackline Master #4: Tracing Back is designed as a way for students to describe how various common items and foods can be traced back to the plant world.

• Blackline Master #5: Carbon Dioxide and Plant Growth is an experiment to illustrate the importance of carbon dioxide to green plants.

• Blackline Master #6: Oxygen as a By-Product is an experiment to show that oxygen is given off by green plants during photosynthesis.

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ENRICHMENT ACTIVITIES

1. Here is the chemical formula for photosynthesis: 6CO₂ + 6H₂O equals C₆H₁₂O₆ + 6O₂. Write this on the board and have a discussion about what everything stands for in the equation. Don't forget to mention sunlight is required and that this happens in green plants that contain chlorophyll.

2. Discuss the importance of green plants to all life on earth. Why must we be careful not to disrupt the wonderful partnership shared by animals and plants?

ANSWER KEY • PRE-TEST, Blackline Master #1

1. photosynthesis

2. water, carbon dioxide, energy from the sun, and chlorophyll within the plant's cells

3. chlorophyll 4. chloroplasts 5. glucose

6. stoma (plural: stomata)

7. Plants are the only living things capable of producing food. All food can be traced back to plants. Oxygen is released during photosynthesis. Also, fuels used to run our vehicles and equipment come from plants.

8. Animals exhale carbon dioxide which plants need for food making and plants release oxygen which animals need to breathe.

9. starch

10. Fossil fuels which include natural gas, oil, and coal were formed from the dead remains of animals and plants that lived millions of years ago. Their remains have changed into these various fuels which are so important to people today.

• VIDEO QUIZ, Blackline Master #2 1. false 2. true 3. false 4. true 5. hydrogen 6. root hairs 7. fossil fuels 8. chlorophyll 9. sun 10. water

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• CROSSWORD, Blackline Master #3

• TRACING BACK, Blackline Master #4

1. wool comes from sheep. Sheep feed on grass. 2. book - paper comes from trees

3. leather purse - made from animal hides. Animals eat plants. 4. cotton - from the cotton plant

5. cake - many materials that go into a cake are from plants (flour, sugar, chocolate, vanilla, fruit)

6. hamburger - comes from cattle which are fed grains and other plants

7. milk - comes from cows that feed on grass and grains

8. bread - made from flour which is ground up grain from plants 9. coal - formed millions of years ago from the remains of

plants

10. honey - made by bees from the nectar of plants • CARBON DIOXIDE AND PLANT GROWTH, Blackline Master #5

This experiment will show that plants need carbon dioxide from the air to carry on photosynthesis. It will also show that the carbon dioxide is taken in through the stomata located on the underside of the leaf. • OXYGEN AS A BY-PRODUCT, Blackline Master #6

This is an experiment to collect oxygen from a live elodea leaf.

1 2 3 4 5 6 7 8 9 p h o t o s y n t h e s i s s o m a c r b o n d i o x i d e h l o r o p h y l l c l o r o p l a s t s x y g e n l u c o s e u n w t e r n e r g y

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INTERNET RESOURCES

The following websites may be valuable sources of additional information to reinforce the objectives of this lesson:

(1.) Tropical Feast at http://www.mobot.org/mobot/education/feast il-lustrates various edible plants and fruits.

(2.) Tropical Rain Forests at http://www.mobot.org/mobot/education/ tropics.

(3.) Coloring Book Drawings at http://www.nps.gov/plants/color/ 20.htm.

(4.) Plant Watch at http://www.devonianm.ualberta.ca/pwatch. • POST-TEST, Blackline Master #7

1. photosynthesis

2. stoma (plural: stomata)

3. water, carbon dioxide, minerals from the soil, energy from the sun

4. chlorophyll 5. chloroplasts 6. glucose 7. starch

8. carbon dioxide, water, glucose, oxygen

9. Green plants are the only living things capable of making food. Plants are at the base of all food chains. Plants release oxygen, which living things need to breathe. Energy used by humans is traced back to plants.

10. All fossil fuels, such as natural gas, oil, and gasoline, have been formed over millions of years from dead animals and plants that received their energy from the sun.

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Photosynthesis Script of Narration

Our fellow humans, the many kinds of plants and animals around us, we’re all alike in one very important way: We all need nourishment. We all need food. Food, in all its forms, is the fuel that keeps the fires of life burning. We humans, and the many different critters sharing the planet with us, get the food we need by eating. Eating isn’t the only way, however, that living things can get their nourishment.

Take green plants, such as the beauty I’m looking at here, for example. They can’t eat. So green plants get their food another way. They make it using one of the most vital process in all nature - photosynthesis. Today we’ll explore how photosynthesis works and why it’s so important.

Let’s start by looking at the word “photosynthesis.” Photo means light, and synthesis means to put something together. And that’s exactly what happens. During photosynthesis, plants use the sun’s energy to put together glucose, a type of sugar, from simpler chemicals.

Here’s an outline of how the process goes. First, plants collect the raw materials they need for photosynthesis. These are two common substances. Water is the first. The second is carbon dioxide. It’s a common gas in the air around us. Their roots absorb the water plants need for photosynthesis. Roots are covered with tiny hair-like growths. Called “root hairs,” they absorb water from the soil. This is then transported to the plant’s leaves, where it’s used.

Leaves are nature’s food factory. They’re where green plants carry on most of their photosynthesis. Here’s a cross-section of a typical leaf as it looks through a microscope. Notice the tiny openings, or pores, on its underside. Called a “stoma,” each of these openings is a tiny “door” through which air, and the carbon dioxide it contains, enters leaves. Once they have water and carbon dioxide, leaves have the raw materials needed for photosynthesis. However, something else is required before the process can actually start. And that “something” is sunlight. That’s because it’s light from the sun that provides the energy for photosynthesis. Look carefully at leaves and you’ll see how well they’re suited to capture the sun’s energy. Their thin shape allows sunlight to easily reach the cells where photosynthesis takes place.

And here’s the leaf’s inside again. The small granules you see in its cells are called “chloroplasts.” They contain a complex, green-colored chemical called “chlorophyll.” However, in this slide, the chloroplasts look blue because of the way in which it was prepared.

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It’s chlorophyll that gives leaves, such as these giant water lilies, their characteristic green color. Chlorophyll also gives the green color to plants such as these cacti and this paloverde bush.

Both live in sun-baked desert areas, and to reduce water loss they grow few, or no, leaves. Instead, as their green color shows, they have chlorophyll in their trunks, stems, and branches, letting them carry on photosynthesis there.

But regardless of where it is, when sunlight falls on chlorophyll, light energy is absorbed and a series of complex chemical reactions begins. These reactions split some of the carbon dioxide molecules plants take in into carbon and oxygen atoms. The same thing happens to some of the water molecules plants absorb. They’re broken apart into hydrogen and oxygen atoms.

Some of the resulting carbon, hydrogen, and oxygen atoms then join together to make glucose, a kind of sugar. This glucose contains stored energy which came from the sun. Plants do different things with the glucose their photosynthesis produces. They use some of it right away as food to provide the energy they need to carry on their life processes. Plants can also change some of the sugar they make into starch and store it for later use. And here we see some of that stored energy. Whenever we dine on potatoes, yams, and similar foods, we’re eating food which plants stored in their roots as starch to meet their future energy needs.

Plants also store energy in their seeds, or, as we sometimes call them, “ grains.” Later, this stored food energy is used by the young plants that sprout from these seeds. We humans also benefit greatly from these energy-rich foods, both by eating them ourselves and by feeding them to our animals.

But, as important as it is, photosynthesis provides far more than just food alone. Take, for example, breathing. It may be hard to believe, but without photosynthesis, we couldn’t. And that’s because the world’s oxygen supply is a by-product of photosynthesis.

Here’s how. Remember how earlier we learned that during photosynthesis plants use light energy to split water molecules into hydrogen and oxygen atoms?

Plants use some of these oxygen atoms for their own life processes. Some of them, however, are released into the air around them. We humans breathe this oxygen - the oxygen photosynthesis produces - as do all the many other other critters, both big and small, that share the planet with us.

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In addition, some of the oxygen photosynthesis produces becomes dissolved in the world’s waters. This is the oxygen that fish and other aquatic critters, such as this crab use, use.

And then there are our fuels! Believe it or not, nearly all the fuels that do such things as power our vehicles, cook our food, and keep us warm come to us thanks to photosynthesis.

Called “fossil fuels,” much of the energy we use comes from fuels formed from the remains of green plants and other organisms that lived, and carried on photosynthesis, millions of years ago. Since then, their remains have changed, into natural gas, oil, and coal. Today, when we burn these fuels, we are actually reaching back into time and benefiting from energy that photosynthesis captured from the sun hundreds of millions of years ago. As we’ve seen today, photosynthesis is one of nature’s most important processes. Powered by the sun’s energy and fueled by water and carbon dioxide, photosynthesis not only gives us, and countless other living things, food, it also provides the oxygen we, and other organisms, breathe, as well as fuels to warm us and power our vehicles.

Now let’s take a few minutes to answer some questions. They’ll help you remember the key points we covered today. The directions are simple. When you hear this tone, check either “true” or “false” or fill in the blank with the correct word. Good luck, and let’s get started.

True or False. One of the raw materials used by green plants during photosynthesis is the gas carbon monoxide.

True or False. Plants can store some of the food they manufacture as starch. True or False. The tiny holes through which gases enter and exit leaves are called chloroplasts.

True or False. During photosynthesis green plants manufacture a sugar called glucose.

Now let’s change the way we’re doing things. Instead of checking “true” or “false,” just fill in the blanks with the correct words after you hear the beep tone.

During photosynthesis water molecules are split into atoms of oxygen and ______ .

Roots absorb the water they need for photosynthesis through tiny outgrowths called ______ .

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Because they are produced from long-dead plants and other organisms, coal, gasoline, and oil are often called ______ fuels.

Green plants get their color from a chemical called ______ .

The energy plants use during photosynthesis comes from the ______ . During photosynthesis sunlight provides the energy to split molecules of carbon dioxide and ______ .

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Name ___________________________

Photosynthesis

PRE-TEST

DIRECTIONS: Answer the following questions in the space provided.

1.Green plants make their own food in a process called ____________________.

2.What are the ingredients plants need to produce their food?

3.The plant's characteristic green color comes from the chemical _____________.

4.This chemical is found in special cells in the leaves called __________________.

5.The plant's food is a form of sugar called _________________.

6.The tiny openings on the underside of leaves are called ___________________.

7.All life on earth depends on plants. How is this possible?

8.Plants and animals have a wonderful partnership. What is it that plants need from

animals and what do plants produce that is essential to animals?

9.Glucose that isn't used by the plant can be stored as _______________.

10.All forms of energy on earth such as the fuels used in our cars are traceable to

plants and sunlight. Explain that statement.

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Name ___________________________

Photosynthesis

VIDEO QUIZ

At the end of the video production is a short quiz. You may right the answers to

the quiz on this sheet.

DIRECTIONS: Mark the following statements either "True" or "False" or fill in the blanks

with the correct words after you hear the tone.

1. True or False? One of the raw materials used by green plants during

photosynthesis is the gas carbon monoxide.

2. True or False? Plants can store some of the food they manufacture as

starch.

3. True or False? The tiny holes through which gases enter and exit leaves

are called chloroplasts.

4. True or False? During photosynthesis, green plants manufacture a sugar

called glucose.

Directions: Answer the following questions by filling in the missing word or with

short answers after you hear the tone.

5. During photosynthesis water molecules are split into atoms of oxygen

and ________________.

6. Roots absorb the water they need for photosynthesis through tiny out

growths called ________________.

7. Because they are produced from long-dead plant material, gasoline

and oil are often called _______________ fuels.

8. Green plants get their color from a chemical called _________________.

9. The energy plants use during photosynthesis comes from the

_________________.

10. During photosynthesis, sunlight provides the energy to split molecules of

carbon dioxide and _________________.

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Name ___________________________

Photosynthesis

CROSSWORD

DIRECTIONS: Fill in the boxes below with the words that complete the paragraph at

the bottom of the page.

Green plants make their own food in a process called (1) _____________________.

They need (2 across) _____________________ _____________________ from the air and

(9) _____________________ from the soil as well as (5) _____________________ from the

(8) _____________________ . The (2 across) _____________________ _____________________

is collected through small openings on the underside of the plant's leaves. Each of

these openings is called a (6) _____________________ . The plant gains its

characteris-tic green color from the chemical (2 down) _____________________ , which is found in

special cells called (4) _____________________ . The leaf's main job then is to make (3)

_____________________, a form of sugar. During this food-making process (7)

_____________________ is released by the plant into the air. That gas is essential for

animal and human survival.

3

1 2 3 4 5 6 7 8 9

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Name ___________________________

Photosynthesis

TRACING BACK

Many things can be traced back to plants. For example, petroleum, which is used

to run cars and trucks, was formed millions of years ago when prehistoric plants and

animals died and were buried under layers and layers of rock and soil.

DIRECTIONS: Try to trace things listed below back to plants. The first one has been

done for you.

1. woolen sweater

Wool comes from sheep. Sheep feed on grass.

2. book

3. leather purse

4. cotton dress

5. cake

6. triple-decker hamburger

7. milk

8. bread

9. coal

10. honey

4

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Name ___________________________

Photosynthesis

CARBON DIOXIDE AND PLANT GROWTH

Purpose:

Green plants produce food during the process of photosynthesis.

One of the ingredients needed by plants is carbon dioxide. Carbon

dioxide is released by animals when they exhale. It is a gas that mixes

with the other gases in the air. The leaves of plants collect the

car-bon dioxide through small openings on the underside of each leaf.

The openings are called stomata. This experiment will illustrate the

importance of carbon dioxide to plants.

Materials:

1. a plant with good sized leaves such as a geranium

2. petroleum jelly

3. towels

Procedures:

1. Cover the top of one leaf with petroleum jelly.

2. Cover the bottom of another leaf with petroleum jelly.

3. Place the plant in sunlight and water it regularly.

Observations:

After three or four days, examine the leaves. Take the petroleum

jelly off each leaf with paper towels. Record what you see.

1. How did the leaf that had petroleum jelly on top compare with other leaves on

the plant?

2. How did the leaf that had petroleum jelly on the bottom compare with other

leaves?

Conclusions:

How can you explain your findings?

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Name ___________________________

Photosynthesis

OXYGEN AS A BY-PRODUCT

Purpose:

Green plants produce food during the process of photosynthesis.

Oxy-gen is given off by plants during this food production. This gas is very important to

life froms on our planet. This experiment will show that oxygen is released by plants

only when photosynthesis is taking place.

Materials:

1. two elodea plants (you can get them from most pet shops)

2. Two test tubes with stoppers

3. Two pans with deep sides

4. Two glass funnels

Procedures:

1. Fill each pan with water almost to the top.

2. Put an elodea plant in the bottom of each pan.

3. Fill the test tubes with water and keep one submerged in each

pan.

4. Place a glass funnel over each plant, making sure the neck of the

funnel is above the water.

5. Put one pan with plant in direct sunlight.

6. Hold the water filled test tube over the funnel and watch the gas

bubbles rise into the tube. As the bubbles rise into the test tube the

water will be displaced and empty out. Wait until most of the test

tube is filled with the gas given off by the elodea.

7. Remove the test tube but stopper it so the gas can't escape.

8. Repeat everything for the other pan and plant but this time put the

set-up in a dark closet.

Observations:

Did gas bubbles rise from the elodea plant in the closet?

To test the gas collected follow these procedures:

a. Remove the stopper from the test tube while holding the test

tube mouth side down.

b. Light a long fireplace match and then blow out the flame.

The match should be glowing.

c. Put the glowing end of the match into the test tube. If it

bursts into flames then pure oxygen is present.

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Name ___________________________

Photosynthesis

POST-TEST

DIRECTIONS: Answer the following questions in the space provided.

1. The process of food making performed by green plants is called

_____________.

2. The tiny openings on the underside of leaves are called ________________.

3. What are the ingredients plants need for their food making process?

4. The green color that leaves have is caused by the chemical

_____________.

5. This green colored chemical is found in cells of the plant's leaf called

____________________.

6. The plant's food is a kind of sugar called ________________.

7. Plant sugar that isn't used by the plant can be stored as _______________.

8. Here is the chemical formula for the food making process that plants

undertake:

6CO

2

+ 6H

2

O C

6

H

12

O

6

+ 6O

2

Identify the various chemicals shown in the formula.

9. How can you support the statement that all life on earth is dependent on

plants?

10. List as many examples as you can that the energy we use on earth is

actually traceable to plants and sunlight.