Overview

Lesson Procedure

60-65 minutes of class time across 5 phases.

1. Warm-Up10 minutes
2. Direct Instruction15-20 minutes
3. Guided Practice15 minutes
4. Independent Practice15 minutes
5. Closure5 minutes

1. Warm-Up10 minutes

   Warm-Up Prompt

   "Think of a movie trailer or the table of contents of a book. What do they tell you before you start? Write one sentence that previews what you will tell a friend about your weekend, in the order you will tell it."

   Take a few answers. Point out that a good preview names the parts in the order they will come, so listeners can follow along. Explain that in grade 7, the introduction of an informative text does the same job. Then introduce today's topic: why leaves change color in the fall. Read the research notes aloud. Students number the 14 notes, put a check next to each note that helps explain the color change, and an X next to any note that is true but off the topic.

   1Note 1. A pigment is a substance that gives something its color. Chlorophyll is the green pigment in leaves.

   2Note 2. Plants use chlorophyll to capture energy from sunlight. In photosynthesis, they use that energy to make sugar from water and carbon dioxide.

   3Note 3. Carotenoids are yellow and orange pigments. They are also what make carrots orange.

   4Note 4. Carotenoids are in leaves all summer, but the larger amount of green chlorophyll hides them.

   5Note 5. As nights grow longer in late summer and fall, many trees make less chlorophyll and then stop making it. The chlorophyll that is left breaks down.

   6Note 6. Anthocyanins are red and purple pigments. Many trees, such as red maples, make them in the fall from sugars in the leaf.

   7Note 7. Sunny fall days and cool nights that stay above freezing lead to the brightest reds. An early frost can weaken the reds.

   8Note 8. In the fall, a layer of cells called the abscission layer grows across the base of each leaf stem. It slowly seals the leaf off from the branch and traps sugars in the leaf. When the layer is complete, the leaf falls.

   9Note 9. Oaks often turn brown. The brown comes from tannins, substances that stay in the leaf after the other pigments break down.

   10Note 10. Birches, aspens and hickories usually turn yellow or gold.

   11Note 11. Pines, spruces and firs are evergreens: they keep most of their needles through the winter.

   12Note 12. It takes about 40 gallons of sugar maple sap to make 1 gallon of maple syrup.

   13Note 13. The General Sherman Tree, a giant sequoia in California, is the largest living tree on Earth by volume.

   14Note 14. Interview with a state park forester (invented for this lesson): "Weather decides how bright the colors are each year, but the calendar decides when they start. The trees are reading the length of the night."

2. Direct Instruction15-20 minutes

   Teach the words of the standard and leave them on the board:

   • Informative/explanatory text: writing that teaches readers about a topic or explains how or why something happens, without arguing for an opinion.
   • Preview: a sentence or two in the introduction that tells readers what the text will explain, in the order it will explain it.
   • Organizing strategies: definition (what a term means), classification (sorting things into groups by what they share), comparison/contrast (how things are alike and different) and cause/effect (why something happens and what it leads to).
   • Formatting, graphics and multimedia: headings over sections; charts, tables and diagrams; and, in a digital text, video, audio or animation. Use them when they help readers understand, not as decoration.
   • Develop: support each section with facts, definitions, concrete details, quotations and examples.
   • Cohesion: the way a text holds together. Writers create it with transitions (as a result, however, at the same time), repeated key terms (the same word for the same thing every time) and words that point back (this layer, those sugars).
   • Domain-specific vocabulary: the exact words of a subject, such as pigment or photosynthesis, defined for readers the first time they appear.
   • Formal style: careful, objective school language with no slang and no opinions.
   • Concluding section: an ending that follows from the information and pulls it together.

   Work through the five examples below. Then show Diagram 2 to explain the preview promise.

   • Previewing what is to follow

     A report on volcanoes has three sections: What Magma Is, How Pressure Builds, and Explosive and Quiet Eruptions. First try at the introduction: This report is about volcanoes.

     Result: Revision: This report explains what magma is, how pressure builds beneath a volcano, and why some eruptions explode while others ooze. The preview names each section in order, so readers know the plan before they start (Diagram 2).

   • Comparison and contrast

     Notes 3, 4 and 6 describe two kinds of pigments: carotenoids and anthocyanins. How can a writer show how they are alike and different?

     Result: Both are pigments that show in fall leaves. However, carotenoids are in the leaf all summer, hidden by green, while many trees make anthocyanins only in the fall. The words both, however and while signal the likeness and the difference.

   • Cause and effect with cohesion

     Three separate notes for the volcano report in Diagram 2: Gas builds up in magma. Pressure rises. The volcano erupts.

     Result: Linked: As gas builds up in the magma, the pressure beneath the volcano rises. Eventually, that pressure grows strong enough to force the magma to the surface, and the volcano erupts. As shows the cause, eventually shows time, and that pressure points back to the sentence before.

   • Selecting relevant content

     A section explains how the leaf is sealed off. Which note belongs there: Note 8 (the abscission layer) or Note 12 (maple syrup)?

     Result: Note 8 belongs, because it explains what seals the leaf off and traps its sugars. Note 12 is true and even mentions a maple, but syrup has nothing to do with how leaves change color, so the writer leaves it out.

   • Precise, domain-specific words

     Draft sentence: Trees grow a wall thing on the leaves and then they drop.

     Result: Revision: A layer of cells called the abscission layer grows across the base of each leaf stem; when the layer is complete, the leaf falls. The revision names the structure, defines it by what it is and where it grows, and replaces drop with the exact event.

   Hand out the model text with Table 1 and Diagram 1. Read it once for meaning. On the second reading, students highlight each item in the preview in one color and the matching heading in the same color, then circle every transition and word that points back. Ask: Which notes did the writer use? Which did the writer leave out, and why? Would a short time-lapse video of a leaf turning red help readers of a digital version, and where would it go?

   1Every fall, hillsides across much of the United States turn from green to gold, orange and red in a few weeks. The trees are not painting their leaves with new colors. Most of those colors were there all along, hidden. This report explains the pigments that color a leaf, what happens to them as the days get shorter, why different trees turn different colors, and why some autumns are brighter than others.

   2The Pigments in a Leaf
   A pigment is a substance that gives something its color. Leaves contain three main kinds, shown in Table 1. The first, chlorophyll, is green. Plants use it to capture energy from sunlight for photosynthesis, the process in which a plant makes sugar from water and carbon dioxide. The second kind, the carotenoids, are yellow and orange; they are the same pigments that make carrots orange. The third kind, the anthocyanins, are red and purple. Unlike the other two, anthocyanins are made mainly in the fall, and only by some trees.

   3What Happens as the Days Get Shorter
   In summer, a leaf holds so much chlorophyll that its green hides the carotenoids. As nights grow longer in late summer and fall, many trees make less chlorophyll and then stop making it. The chlorophyll that remains breaks down, and as the green fades, the yellow and orange carotenoids finally show. At the same time, a layer of cells called the abscission layer grows across the base of each leaf stem. This layer slowly seals the leaf off from the branch and traps sugars inside it. In trees such as red maples, those trapped sugars become red anthocyanins. Once the layer is complete, the leaf falls. Diagram 1 shows this chain of causes and effects.

   4Why Different Trees Turn Different Colors
   Each kind of tree shows the pigments its leaves contain. Birches, aspens and hickories usually turn yellow or gold, because their fall color comes from carotenoids. Red maples add anthocyanins, so their leaves turn red. Oaks often turn brown, the color of tannins, which are substances that stay in the leaf after the other pigments break down. Evergreens such as pines, spruces and firs keep most of their needles through the winter, so they stay green.

   5Why Some Years Are Brighter
   The timing of the change depends mainly on the length of the night, which is the same on the same date every year. The brightness, however, depends on the weather. Sunny fall days help leaves make plenty of sugar, and cool nights that stay above freezing help keep that sugar in the leaf, where it becomes red pigment. An early frost, on the other hand, can weaken the reds. A state park forester put it this way: "Weather decides how bright the colors are each year, but the calendar decides when they start."

   6A leaf's fall colors, then, are the end of a chain of events that begins with longer nights. As the chlorophyll fades, hidden yellows and oranges appear; where sugars are trapped, reds develop; and where only tannins remain, the leaf turns brown. With this chain in mind, anyone who looks at an October hillside can tell which pigments each tree is showing.

   Table 1 (part of the model text): The pigments in a leaf

   Pigment	Color	When the leaf has it	Trees that show it in fall
   Chlorophyll	Green	All summer; breaks down in fall	Evergreens stay green
   Carotenoids	Yellow and orange	All summer, hidden by green	Birches, aspens, hickories
   Anthocyanins	Red and purple	Made mainly in fall, by some trees	Red maples

3. Guided Practice15 minutes

   Pairs complete the map of the model text below in their own words. For each body section, they name the main organizing strategy and copy one word or phrase that ties it to the section before. Circulate and ask each pair to show which part of the preview each heading answers.

   Map of the model text (students fill in the last three columns)

   Paragraph	Heading	What this part explains	Main strategy	Link to what came before
   1	(introduction)
   2	The Pigments in a Leaf
   3	What Happens as the Days Get Shorter
   4	Why Different Trees Turn Different Colors
   5	Why Some Years Are Brighter
   6	(conclusion)

   Next, pairs read the weak draft below on the same topic. They list its problems with the introduction, the facts chosen, the organization, the words, the links between sentences and the ending. They do not rewrite it yet; that happens in Activity 3.

   Leaves change color in the fall and it's really pretty. There's green stuff in them. Then it goes away. Some trees are red and some are yellow. Also it takes 40 gallons of sap to make syrup!! And the General Sherman tree is huge. The leaves fall off too. So that's why leaves change color.

4. Independent Practice15 minutes

   Each student writes a new section for the model text titled What Evergreens Do Differently. Use Note 11 and at least one other note. The section needs the heading, a first sentence that ties it to an earlier section with a word that points back, one comparison between evergreens and trees that lose their leaves, at least two transitions, and one domain-specific word with its meaning. Then students revise the preview in paragraph 1 so that it promises the new section in the right place, and explain the change in one sentence. Collect the sections to check that every fact is relevant and accurate.

5. Closure5 minutes

   Exit ticket: (1) Copy your revised preview. (2) Circle one word in your section that points back to an earlier idea and name what it points to. (3) Name one note you left out and say why.

   Hand out the homework fact sheet below. It gives 14 facts about hurricanes for students to select from, organize and explain. Students also use it for questions 7, 13, 17, 19 and 20 of the quiz.

   1Fact 1. A hurricane is a large, rotating storm that forms over warm ocean water and has sustained winds of at least 74 miles per hour.

   2Fact 2. Hurricanes usually form where the surface of the ocean is at least about 80°F (about 27°C).

   3Fact 3. Warm, moist air rises from the ocean surface. As the air rises and cools, its water vapor turns into cloud droplets and releases heat. That heat powers the storm.

   4Fact 4. A rotating storm with sustained winds of 39 to 73 miles per hour is called a tropical storm, and it is given a name.

   5Fact 5. The eye is the calm, often clear center of a hurricane. The eyewall, the ring of thunderstorms around the eye, has the strongest winds.

   6Fact 6. In the Northern Hemisphere, a hurricane's winds turn counterclockwise. In the Southern Hemisphere, they turn clockwise.

   7Fact 7. The Saffir-Simpson scale sorts hurricanes into five categories by wind speed, from Category 1 (74 to 95 miles per hour) to Category 5 (157 miles per hour or higher).

   8Fact 8. The same kind of storm is called a typhoon in the northwestern Pacific Ocean and a cyclone in the South Pacific and Indian Oceans.

   9Fact 9. The Atlantic hurricane season runs from June 1 to November 30.

   10Fact 10. Over land or cool water, a hurricane loses its supply of warm, moist air and weakens.

   11Fact 11. Storm surge is a rise in sea level that a storm's winds push onto the shore. It can flood coastal towns.

   12Fact 12. The English word hurricane comes from the Spanish word huracán, which was borrowed from the Taíno language of the Caribbean.

   13Fact 13. Flight crews known as Hurricane Hunters fly specially equipped airplanes into hurricanes to collect measurements.

   14Fact 14. Comment from a meteorologist (invented for this lesson): "A hurricane is a heat engine. Take away the warm water, and it runs out of fuel."

Differentiation Strategies

Assessment Guidance

1. Question 1 of 20 · Multiple Choice

   A report on glaciers has three sections: Where Glaciers Form, How Glaciers Move and How Glaciers Shape the Land. Which sentence best previews what is to follow?

   AGlaciers are some of the most amazing sights on Earth, and they are worth a visit. BThis report explains where glaciers form, how they move, and how they shape the land. CThis report is about glaciers, which are large, slow-moving bodies of ice found on land. DSome glaciers move less than a meter a day, while others can move much faster.

2. Question 2 of 20 · Multiple Choice

   In paragraph 1 of the model text, which sentence previews what is to follow?

   AEvery fall, hillsides across much of the United States turn from green to gold, orange and red in a few weeks. BThe trees are not painting their leaves with new colors. CThis report explains the pigments that color a leaf, what happens to them as the days get shorter, why different trees turn different colors, and why some autumns are brighter than others. DMost of those colors were there all along, hidden.

3. Question 3 of 20 · Multiple Choice

   Which organizing strategy does the section Why Different Trees Turn Different Colors (paragraph 4) mainly use?

   AClassification: it sorts trees into groups by the pigment they show. BDefinition: it explains what the word pigment means before using it. CTime order: it tells what happens to one tree from spring to winter. DProblem and solution: it names a problem trees face and how they solve it.

4. Question 4 of 20 · Multiple Choice

   According to paragraph 3, why do the yellow and orange carotenoids "finally show" in the fall?

   ABecause the leaf makes new carotenoids once the nights grow longer BBecause the green chlorophyll that hid them all summer breaks down CBecause an early frost turns the chlorophyll in the leaf yellow DBecause the abscission layer traps yellow sugars inside the leaf

5. Question 5 of 20 · Multiple Choice

   Why does the model text use headings such as The Pigments in a Leaf and Why Some Years Are Brighter?

   ATo make the report look longer and more serious than it would without them BTo replace the first sentence of each section, which would otherwise be needed CTo show the writer's opinion of each topic before the facts are explained DTo show readers what each section explains, in the order the preview promised

6. Question 6 of 20 · Multiple Choice

   A writer wants to show readers how the number of daylight hours in one town drops from June to December. Which graphic would help most?

   AA line graph with months along the bottom and daylight hours up the side BA photograph of a red maple taken in the middle of October in that same town CA table that lists each leaf pigment next to the color that it gives the leaf DA heading that says Shorter Days above the paragraph about daylight

7. Question 7 of 20 · Multiple Choice

   You are writing the section of your hurricane text that explains what gives a hurricane its power. Which fact from the homework fact sheet is most relevant?

   AFact 12, about where the English word hurricane comes from BFact 9, about the dates of the Atlantic hurricane season CFact 3, about heat released as water vapor forms clouds DFact 13, about crews who fly airplanes into hurricanes

8. Question 8 of 20 · Multiple Choice

   The writer of the model text left out Note 13, about the General Sherman Tree. What is the best reason?

   AThe note is not accurate, so it cannot be used in a report. BThe note is true, but it has nothing to do with why leaves change color. CThe note is covered in paragraph 4 with the other evergreen trees. DThe note is a quotation, and informative texts cannot include quotations.

9. Question 9 of 20 · Multiple Choice

   What does the forester's quotation add to paragraph 5?

   AIt gives the number of days it takes for a leaf to change color. BIt argues that people should visit state parks in the fall. CIt sums up the difference between timing and brightness in an expert's words. DIt introduces a new cause of fall color that the text has not explained until now.

10. Question 10 of 20 · Multiple Choice

    In paragraph 3, the writer begins a sentence with This layer. What does This layer refer to?

    AThe green layer of chlorophyll that covers the whole surface of the leaf BThe layer of fallen leaves that covers the ground in autumn CThe layer of red anthocyanins that forms in a red maple leaf DThe layer of cells that grows across the base of each leaf stem

11. Question 11 of 20 · Multiple Choice

    Choose the transition that best fills the blank: Anthocyanins are made from sugars trapped in the leaf. ____, a fall with many sunny days, when leaves make more sugar, often brings brighter reds.

    AHowever BFor this reason CFor example DIn the same way

12. Question 12 of 20 · Multiple Choice

    In paragraph 5, which word or phrase signals that the brightness of the colors works differently from their timing?

    Ahowever Bmainly Cput it this way Devery year

13. Question 13 of 20 · Multiple Choice

    Which sentence about hurricanes uses the most precise, domain-specific language?

    AThe middle part of a hurricane is calm, but the part around it is really bad. BHurricanes have a quiet spot in them, and the winds all around it are super strong. CThe eyewall, the ring of thunderstorms around the eye, has the strongest winds. DThere is a part of the storm where things get calmer and a part where things get worse.

14. Question 14 of 20 · Multiple Choice

    Which revision of the weak draft's first sentence keeps a formal style?

    ALeaves change color in the fall, and honestly it is the best time of year. BYou have probably noticed that leaves get super colorful in the fall. CLeaves change color in the fall, which is really pretty and totally worth going outside to see. DEach fall, the leaves of many trees change from green to yellow, orange, red or brown.

15. Question 15 of 20 · Short Answer

    Paragraph 6 is the model text's concluding section. Explain in two or three sentences how it follows from and supports the information presented. Name at least two earlier sections it draws on.

    Show model answer

16. Question 16 of 20 · Short Answer

    A report on the Moon has three sections: Why the Moon Shines, The Moon's Monthly Orbit and The Names of the Phases. Write an introduction of two or three sentences that names the topic clearly and previews what is to follow.

    Show model answer

17. Question 17 of 20 · Short Answer

    Use the homework fact sheet. Join these two sentences into one sentence that shows how they are related. Use a transition, and name the relationship it shows: Over land, a hurricane loses its supply of warm, moist air. The storm weakens.

    Show model answer

18. Question 18 of 20 · Short Answer

    Revise these sentences from the weak draft so that they are cohesive and use precise, domain-specific words: "There's green stuff in them. Then it goes away. Some trees are red and some are yellow."

    Show model answer

19. Question 19 of 20 · Short Answer

    Use the homework fact sheet. Explain in two or three sentences how warm ocean water gives a hurricane its power. Use at least one domain-specific word and one transition.

    Show model answer

20. Question 20 of 20 · Short Answer

    Use the homework fact sheet. Choose information that would be clearer in a table than in a paragraph. Name the facts you would use, write the table's column headings, and explain in one sentence how the table would help readers.

    Show model answer

These standards connect to W.7.2: prerequisites to review first, parallel standards at the same level, and next steps that build on it.

Standard text: Common Core State Standards for English Language Arts & Literacy. © Copyright 2010. National Governors Association Center for Best Practices and Council of Chief State School Officers. All rights reserved.