WHST.9-10.2Common CoreELAWriting in History, Science and Technical SubjectsGrades 9-10
WHST.9-10.2: Explaining a Science Procedure and Narrating an Experiment
In plain English: WHST.9-10.2 is the Common Core literacy standard that asks students in grades 9 and 10 to write informative and explanatory texts in science, history and technical subjects, such as an account of an experiment or procedure. Students organize ideas to show connections and distinctions, develop the topic with relevant facts, use precise vocabulary, keep a formal, objective tone and write a conclusion that follows.
Write informative/explanatory texts, including the narration of historical events, scientific procedures/experiments, or technical processes.
a.Introduce a topic and organize ideas, concepts, and information to make important connections and distinctions; include formatting (e.g., headings), graphics (e.g., figures, tables), and multimedia when useful to aiding comprehension.
b.Develop the topic with well-chosen, relevant, and sufficient facts, extended definitions, concrete details, quotations, or other information and examples appropriate to the audience's knowledge of the topic.
c.Use varied transitions and sentence structures to link the major sections of the text, create cohesion, and clarify the relationships among ideas and concepts.
d.Use precise language and domain-specific vocabulary to manage the complexity of the topic and convey a style appropriate to the discipline and context as well as to the expertise of likely readers.
e.Establish and maintain a formal style and objective tone while attending to the norms and conventions of the discipline in which they are writing.
f.Provide a concluding statement or section that follows from and supports the information or explanation presented (e.g., articulating implications or the significance of the topic).
Common Core State Standards for English Language Arts & Literacy · Domain: Writing Standards for Literacy in History/Social Studies, Science, and Technical Subjects 6-12 · Cluster: Text Types and Purposes · Official standard
Students learn to write the kind of explanation a science reader needs: not only what was done in a procedure, but why each step works and how the steps depend on one another. The lesson is built on a classic classroom procedure, pulling visible DNA out of a strawberry with soap, salt and cold alcohol. Students study an original model text that explains the procedure in three stages, diagnose a weak lab write-up, and then turn a set of lab notebook notes into a narration of an experiment. All data in the notebook notes are invented for this lesson and labeled as such.
The lesson follows the six parts of WHST.9-10.2: introducing the topic and organizing it to show connections and distinctions, with headings and graphics where they help (a); developing it with relevant, sufficient facts, definitions and concrete details for the audience (b); linking sections with varied transitions and sentence structures (c); using precise, domain-specific vocabulary in a style that suits the discipline and the readers (d); keeping a formal style and objective tone that follows the norms of science writing (e); and ending with a conclusion that follows from the explanation, for example by stating its significance (f).
Learning Objectives
By the end of this lesson, students will be able to:
Introduce a science topic and organize an explanation so that it shows how steps connect and how key terms differ
Select relevant and sufficient facts, definitions and concrete details for a named audience, and leave out facts that do not serve the explanation
Decide when a heading, a table or a figure helps readers more than a paragraph
Link the sections of an explanation with varied transitions and sentence structures
Narrate a procedure and its results with precise vocabulary, a formal, objective tone and a conclusion that follows
Prior Knowledge Required
Students should already be comfortable with:
Writing informative texts about science and history topics WHST.6-8.2
Following a multistep procedure in an experiment RST.6-8.3
Knowing that cells contain DNA and that plant cells have a cell wall and a cell membrane
"A recipe for bread tells you to let the dough rise for an hour. What would a reader need to know that the recipe leaves out, if the reader wanted to understand why the dough rises?"
Give students two minutes to write, then collect answers in two columns: what to do (the step) and why it works (the explanation). Point out that a lab procedure is like the recipe: it lists steps. An informative text about a procedure adds the second column and shows how each step makes the next one possible. Tell students that today's procedure makes DNA visible, and ask them to predict one problem the procedure must solve before anyone can see DNA.
Direct Instruction20 minutes
Show Diagram 1 and explain that the model text is organized around three problems, each solved by one stage of the procedure. Stress two words from standard a: an explanation makes connections (how one step makes the next possible) and distinctions (how two terms that sound alike differ). Show Diagram 2 for the distinctions. Then work through the five examples below.
Introducing a topic
Vague draft opening: This lab is about DNA and strawberries. It names a subject but gives the reader no problem to follow and no plan.
Result: Revision: How can a class see DNA at all, when one molecule is far too thin for any school microscope? The answer lies in what mashing, soap, salt and cold alcohol each do to a strawberry's cells.
Making a distinction
Draft: The soap breaks the cell open. The sentence runs together two layers and two stages.
Result: Revision: Mashing tears the cell walls; the soap then dissolves two different membranes, the cell membrane that encloses the whole cell and the nuclear membrane that encloses the nucleus.
Extended definition
Term to define for readers who have never done the lab: crude extract.
Result: A crude extract is a sample in which the substance a scientist wants has been separated from most of its source, but not from everything. The strands from a strawberry are a crude extract: they are mostly DNA, yet they still carry other cell material, so they are good for seeing DNA but not for testing it.
A transition that shows a relationship
Two unlinked sentences: Mashing tears the cell walls. Soap dissolves the membranes.
Result: Revision: Once mashing has torn the cell walls, the soap can reach the membranes underneath and dissolve them. ("Once" shows that the second step depends on the first.)
Formal style and the norms of science writing
Draft: Then you pour the mushy stuff through the filter thing and it takes forever!!!
Result: Revision: The mashed mixture was poured through a coffee filter into a test tube, and filtering took several minutes. (Past tense for what was done, the name of each material, a measured description instead of "forever," no "you" and no exclamation.)
Read the model text aloud once for meaning. On the second reading, students mark the sentence in paragraph 1 that previews the organization, circle each heading, and underline every word that links one stage to the next. Ask: which paragraph explains what the result is not, and why would a science reader need that paragraph?
1Every cell in a strawberry carries the plant's DNA, the molecule that stores its genetic instructions, but a single DNA molecule is far too thin to see, even with a classroom microscope. A short procedure with a zip-top bag, dish soap, table salt and cold rubbing alcohol can collect enough DNA from one strawberry to lift out on a wooden stick. The procedure works in three stages, and each stage solves a different problem: the first breaks the cells open, the second frees the DNA from the material around it, and the third brings the DNA out of the liquid so that it becomes visible.
2Stage 1: Breaking the Cell Walls A plant cell is protected by two layers. The outer layer, the cell wall, is a stiff frame made mostly of cellulose. Inside it, the cell membrane is a thin, flexible film of fats called lipids, and it holds the cell's contents. Mashing a strawberry in a closed zip-top bag for about two minutes tears open the cell walls, which are too tough for soap to dissolve.
3Stage 2: Dissolving the Membranes Breaking the walls is not enough, because the DNA is still wrapped inside membranes: the cell membrane and the nuclear membrane around the nucleus, where most of the cell's DNA is stored. The next step adds about 10 mL of an extraction solution of water, dish soap and salt, and the mashing continues for one more minute. Soap dissolves membranes for the same reason that it cleans a greasy pan: its molecules attach to the lipids and break the film apart into tiny droplets. The salt has a different job. DNA carries a negative electric charge along its backbone, and the positive sodium ions from the salt partly cancel that charge, so the DNA strands can later clump together instead of repelling one another. The mixture is then poured through a coffee filter, which holds back the seeds and pulp and lets the liquid, now carrying the DNA, drain into a test tube.
4Stage 3: Making the DNA Visible In the filtered liquid, the DNA is dissolved: its molecules are spread out among the water molecules and cannot be seen. Ice-cold rubbing alcohol is poured slowly down the side of the tilted tube until it forms a layer as deep as the liquid below. The alcohol floats because it is less dense than the watery extract. DNA does not dissolve in alcohol, so where the two layers meet, the DNA comes out of solution, or precipitates, as white, cloudy strands. Chilled alcohol usually gives a larger clump than room-temperature alcohol. After a few minutes, the strands can be wound onto a stick, a step called spooling.
5What the Strands Are, and What They Are Not The white material on the stick is neither a single molecule nor pure DNA. Each strand is a tangle of many thousands of DNA molecules mixed with other cell material. Strawberries give an unusually large amount, in part because their cells hold eight sets of chromosomes, while human body cells hold two. The result is a crude extract: useful for seeing DNA, but not the purified sample a genetics laboratory would test.
6Each stage depends on the one before it: the soap cannot reach the membranes until the mashing has opened the walls, and the alcohol cannot gather DNA that is still locked inside the nuclei. The same three stages of opening the cells, separating the DNA and precipitating it out of solution underlie the more exact methods that laboratories use to prepare DNA for medical and forensic tests.
SVHS lesson authors, Model explanatory text (science procedure): Pulling DNA Out of a Strawberry. Original passage written for this page.
Guided Practice15 minutes
Pairs complete the map below for the model text, filling in the right-hand column in their own words. Then they read the weak draft that follows, which a student wrote after doing the same lab, and list every problem they find: the opening, the order of ideas, the facts, the vocabulary, the tone and the conclusion. They do not rewrite it yet; that happens in Activity 3.
Organization map of the model text (T1)
Paragraph
Heading or role
What the paragraph does (students fill in)
1
Introduction
2
Stage 1: Breaking the Cell Walls
3
Stage 2: Dissolving the Membranes
4
Stage 3: Making the DNA Visible
5
What the Strands Are, and What They Are Not
6
Conclusion
So basically we did the strawberry DNA lab and it was super cool. First you smash up the strawberry. Then you put the soap stuff in and smash it more. The soap kills the cells. Then we filtered it. Then we added the alcohol and the DNA appeared like magic!!! The salt is there for flavor I think, or maybe to make it heavier. We got a big glob of DNA which was one giant DNA molecule. In conclusion, strawberries are awesome and everyone should try this.
SVHS lesson authors, Weak draft for revision (biology class): DNA Lab. Original passage written for this page.
Independent Practice20 minutes
Explain the difference between the two texts students will write. The model text explains a procedure: how and why it works. A narration of an experiment tells what a class did to answer a question, in order, and what it found. Students read the lab notebook notes below, from a class that tested two changes to the procedure (invented data for this lesson). They number the paragraphs, mark each note as question, method, result or limitation, and cross out any note that a reader of a lab report would not need.
1Question: Does leaving the salt out of the extraction solution, or using room-temperature alcohol instead of chilled alcohol, change how much material the strawberry procedure collects?
2Twelve groups each used one fresh strawberry. The strawberries were weighed first; their masses ranged from 14 g to 18 g.
3Four groups followed the standard procedure: 10 mL of extraction solution with salt, and 91 percent isopropyl alcohol chilled overnight in a laboratory freezer rated for flammable liquids.
4Four groups used an extraction solution made without salt. Their alcohol was chilled in the same freezer.
5Four groups used the solution with salt, but their alcohol was kept on the counter at room temperature, about 21 °C.
6Every group mashed its strawberry for 2 minutes, added the solution, mashed for 1 more minute, filtered the mixture into a test tube and poured 10 mL of alcohol slowly down the side of the tube.
7After 5 minutes, each group wound the strands onto a wooden stick, weighed the stick and strands on a balance that reads to 0.01 g, and subtracted the mass of the dry stick.
8Wet mass of the spooled strands, in grams. Standard procedure: 0.52, 0.47, 0.61, 0.44. No salt: 0.18, 0.09, 0.22, 0.15. Room-temperature alcohol: 0.35, 0.29, 0.41, 0.31.
9In the no-salt tubes, the material formed thin, scattered wisps instead of one clump, and two of those groups had trouble winding it onto the stick.
10The strawberries came from a grocery store and were bought the day before the lab. Their color was a deep red.
11The strands were weighed wet, so each mass includes water and alcohol trapped in the clump, not DNA alone.
SVHS lesson authors, Lab notebook notes (invented data): Salt and Temperature Trials. Original passage written for this page.
Each student then writes a plan for a narration of this experiment: a working title, three or four headings, the question in one sentence, and one sentence that connects the no-salt result to the explanation of salt in the model text (T1, paragraph 3). Collect the plans; students draft the narration for homework.
Closure5-10 minutes
Exit ticket: (1) Name one connection between two stages of the procedure, using a transition that shows it. (2) Name one distinction the model text makes between two terms. (3) Write one sentence of your narration in a formal, objective tone.
Safety note for an optional demonstration: 91 percent isopropyl alcohol is highly flammable, its vapor can ignite, it irritates the eyes and skin, and it is poisonous if swallowed. Use only a small, capped amount in a well-ventilated room with no open flames, hot plates or other ignition sources, and wear safety goggles; gloves are recommended. Do not chill it in an ordinary household refrigerator or freezer, whose switches and motors can ignite the vapor: use a unit rated for flammable storage, or chill the capped, labeled bottle in an ice bath. Do not let students taste any part of the procedure, and dispose of the used alcohol according to your school's chemical hygiene and waste rules, never down a drain.
Differentiation Strategies
For Struggling Students
Give sentence frames for connections and distinctions: "Because ... , the next step can ... ." and "Although ... and ... sound alike, ... while ... ."
Provide the lab notebook notes already sorted into question, method, results and limitation, so students can focus on writing the narration
Let students build the explanation from Diagram 1 as a fill-in organizer before they write paragraphs
For Advanced Students
Ask students to write a short paragraph for the narration that explains why the no-salt result fits the model text's account of salt, and what result would have contradicted it
Have students rewrite paragraph 3 of the model text for a chemistry class that already knows what ions are, and explain every change
Ask students to design a fourth trial that would test whether the soap is needed, naming what they would change and what they would keep the same
Assessment Guidance
What to Look For
Check that the introduction names the problem the procedure solves and previews how the text is organized. Each step should be explained, not only listed, and the text should show at least one connection (why one step depends on another) and one distinction (how two terms differ). Facts should be relevant to the question and sufficient for the stated readers, with terms defined where those readers need it. Look for transitions that name a relationship (because, once, as a result, in contrast), sentences that vary in structure, a formal, objective tone, past tense for what was done, quantities with units, and a conclusion that follows from the explanation instead of praising the lab.
02
Classroom Activities
3 Activities
1
Step or Explanation? Sentence Card Sort
15 minPairs
Pairs sort twelve sentence cards about the strawberry procedure into steps and explanations, match each step with the explanation that belongs to it, and pick out two pairs of terms the text must distinguish. The activity builds standards a, b and d.
Sentence Cards
1. Mash the strawberry in a closed bag for two minutes.
2. The mashing tears open the stiff cell walls.
3. Add 10 mL of extraction solution and mash for one more minute.
4. Soap molecules attach to the lipids of the membranes and break them apart.
5. Sodium ions from the salt partly cancel the negative charge on DNA.
6. Pour the mixture through a coffee filter into a test tube.
7. The filter holds back seeds and pulp.
8. Pour chilled alcohol slowly down the side of the tube.
9. The alcohol floats because it is less dense than the extract.
10. DNA cannot stay dissolved in alcohol, so it precipitates.
11. Wind the white strands onto a wooden stick.
12. The strands are a crude extract, not pure DNA.
Procedure
Pairs sort the cards into two piles: steps (what to do) and explanations (why it works)
Teacher key: cards 1, 3, 6, 8 and 11 are steps; cards 2, 4, 5, 7, 9, 10 and 12 are explanations
Pairs place each explanation next to the step it explains; card 2 goes with card 1 and card 7 with card 6; cards 4 and 5 both belong with card 3, and cards 9 and 10 with card 8; card 12 explains the result of card 11 rather than a step
Each pair writes one sentence that joins a step and its explanation with a transition that shows the relationship, for example "Because ..." or "..., which ..."
Finally, pairs find two pairs of terms on the cards that a reader could confuse and write one distinction sentence for each
Discussion Questions
Why are there more explanation cards than step cards? What does that tell you about the difference between a procedure and an explanation?
Which two steps have two explanations each, and why would a writer need both explanations for each of them?
Which card would you leave out for readers who only want to repeat the procedure at home? Which would you keep for a biology class?
2
Heading, Table or Figure?
20 minGroups of 3-4
Groups plan the formatting and graphics for the same content for two different audiences, and decide which information belongs in a heading, a table, a figure, a short video clip or a paragraph. The activity builds standards a and d.
Audience Cards
Audience 1: a lab report for a biology teacher, who knows the vocabulary and wants to judge whether the class's results support the explanation
Audience 2: a one-page handout for a family science night, read by parents and younger siblings who have never heard of lipids or precipitation
Procedure
Using the lab notebook notes (T3), groups list every piece of information the text could include
For each audience, groups mark each item: heading, table, figure, video clip, paragraph or leave out, and write one reason for each choice
Groups write the headings they would use for each audience; the lab report headings should follow the order in which a science reader expects to meet the parts of a report
Groups sketch one figure for the handout and one table for the lab report, with a title and labeled columns or parts
Two groups present, and the class names one choice that fits one audience but not the other
Discussion Questions
Which information did you put in a table for the teacher but in a sentence, or not at all, for the families? Why?
When would a short video clip of the alcohol being poured help a reader more than a figure?
How did the words in your headings change between the two audiences?
Modification for Distance Learning
Groups work in a shared slide file with one slide per audience. Each group posts its headings, its table and a photo or drawing of its figure, and leaves one comment on another group's choices.
3
Lab Write-Up Repair
20 minPairs
Pairs revise the weak draft (T2) into a formal explanation of one paragraph for a biology teacher, using a transition bank and a science conventions checklist, and end it with a conclusion that follows. The activity builds standards c, d, e and f.
Materials
The weak draft (T2), the list of problems from Guided Practice, and the model text (T1)
Transition bank, by relationship: sequence (first, next, once, after), cause and effect (because, so, as a result, which allows), contrast (however, in contrast, whereas, while), explanation (in other words, that is, this means)
Science conventions checklist: past tense for what was done; quantities with units; the name of each material (isopropyl alcohol, not "the alcohol stuff"); observations kept separate from explanations; no "you", no slang, no exclamation marks; claims no stronger than the lab can support
Procedure
Replace the first sentence with an introduction that names the problem the procedure solves
Correct the sentence "The soap kills the cells" so that it states what the soap does, using T1, paragraph 3
Correct the statement about "one giant DNA molecule" using T1, paragraph 5
Add one sentence that explains why the mixture is filtered before the alcohol is added, beginning with a transition that shows cause and effect
Rewrite the last sentence so that it follows from the explanation, for example by stating why the procedure matters
Trade with another pair and label every transition with the relationship it shows
Technical Writing Variation
Pairs rewrite the same content as a numbered procedure for a lab manual. Each step begins with a command verb and gives a quantity or time, and a short note after a step explains its purpose only when a reader needs it to avoid an error. Students compare the two versions and say what each form does better.
03
Diagrams & Visual Aids
2 diagrams
Diagram 1: Three Stages, Three Problems
The model text is organized around three problems. Each stage of the procedure solves one of them, and its result removes the obstacle that blocks the next stage, which is the connection the text's transitions make explicit.
Diagram 2: Distinctions the Explanation Must Make
Three distinctions a science writer keeps clear when explaining the strawberry procedure or narrating an experiment with it. The quoted phrases are short illustrations; in a full text, each side of a pair gets its own sentence or section.
04
Homework Assignment
~30 min
WHST.9-10.2 Homework: Narrating the Salt and Temperature Experiment
Directions: Using the lab notebook notes (T3) in Independent Practice, write a narration of the class experiment for your biology teacher, 350-500 words, in the form of a short lab report. Use the model text (T1) to explain what the results mean. The data are invented for this lesson; say so in your report. Cite notes as (T3, paragraph 8) and the model as (T1, paragraph 3).
Part 1: Introduce and Select (Problems 1-2)
Write an introduction of two or three sentences that states the question the class tested, says why a reader should care about it, and previews how your report is organized.
List the notes from T3 that you will use and the notes you will leave out. For each note you leave out, write one sentence explaining why your teacher does not need it; for one note you keep, explain what your teacher would miss without it.
Part 2: Method and Results (Problems 3-4)
Write the method section: narrate what the groups did, in order, in the past tense, with every quantity and time from the notes and the precise name of each material. Do not use "you".
Compute the mean wet mass for each of the three conditions. Then build a results table with a title, a heading for each column and units, and give your report three or four headings of your own.
Part 3: Explain and Conclude (Problems 5-6)
Write a discussion paragraph that explains the results using the model text: connect the no-salt result to the explanation of salt (T1, paragraph 3) and the room-temperature result to the explanation of chilled alcohol (T1, paragraph 4). Use at least three different transitions and underline them.
Write a conclusion of two or three sentences that follows from your results, states one limitation from the notes, and names one implication for anyone who repeats the procedure. Then reread your report for tone and list two changes you made so that it suits a biology teacher.
Rubric
Criterion
Full Credit (2 pts)
Partial Credit (1 pt)
No Credit (0 pts)
Introduction and Organization
States the question and previews the report; headings and a titled table organize the method, results and discussion
Question stated but no preview, or headings missing
No clear question or order
Facts and Explanation
Relevant, sufficient facts with units; correct means; results connected to the model's explanation of salt and cold alcohol
Some facts missing or irrelevant; one connection explained
Facts inaccurate or no explanation
Transitions and Vocabulary
Varied transitions and sentence structures link the sections; precise terms (precipitate, lipid, extract) used correctly
Transitions repetitive or vocabulary vague in places
No transitions; vague or wrong terms
Style, Tone and Conclusion
Formal, objective tone; past tense for methods; conclusion follows from the results and states a limitation and an implication
Some informal lapses, or conclusion only repeats
Informal throughout or no conclusion
05
Quiz: 20 Questions
Interactive, with answers
Instructions
The questions use the model text (T1) and the weak draft (T2) in the lesson plan, and the lab notebook notes (T3) in Independent Practice. Your score updates as you answer, and Reset quiz clears everything so you or your students can try again.
Multiple choice: pick an option to check it. Short answer: write your answer, then reveal the model answer.
0 of 20 answered · 0 correct
Question 1 of 20 · Multiple Choice
Which writing task asks for an informative/explanatory text rather than an argument?
Answer: B
B asks the writer to explain how a procedure works, which is the purpose of an informative/explanatory text. A and D ask the writer to persuade a reader, and C asks for a claim defended with reasons; all three are arguments.
Question 2 of 20 · Multiple Choice
In paragraph 1 of the model text (T1), which sentence previews how the whole explanation is organized?
Answer: C
C names the three stages in the order the paragraphs follow, so it previews the organization. A states the problem, and B introduces the procedure without its plan. D sums up the stages, but it comes from the conclusion in paragraph 6, not from paragraph 1.
Question 3 of 20 · Multiple Choice
What distinction does paragraph 2 of the model text (T1) make?
Answer: B
Paragraph 2 describes the wall as "a stiff frame made mostly of cellulose" and the membrane as "a thin, flexible film of fats called lipids." A is not in the text. C misreads paragraph 3, where soap dissolves both membranes and salt has a different job. D is a real distinction, but paragraph 4 makes it, not paragraph 2.
Question 4 of 20 · Multiple Choice
Paragraph 3 of the model text (T1) says that soap dissolves membranes "for the same reason that it cleans a greasy pan." Why does the writer include this comparison?
Answer: A
The comparison is a concrete example chosen for the audience: grease on a pan is familiar, and the lipids in a membrane behave the same way. B draws a conclusion the text never states, C invents a safety step, and D mistakes a supporting example for a change of topic.
Question 5 of 20 · Multiple Choice
A writer revising paragraph 4 of the model text (T1), which explains Stage 3, can add one more fact. Which fact is most relevant to that paragraph's explanation?
Answer: C
Paragraph 4 says that "DNA does not dissolve in alcohol" but not why; C supplies the reason, so it develops the paragraph's own point. A and B are true but do not explain Stage 3, and D is false: the procedure also works with other fruits, and paragraph 5 says only that strawberries give "an unusually large amount."
Question 6 of 20 · Multiple Choice
You are writing the family science night handout, for parents and younger siblings who have never studied cells. Which addition best fits their knowledge?
Answer: B
Readers without science training need the idea the explanation depends on, in familiar terms, and B supplies it. A and C give detail these readers cannot use, and D uses a term without defining it for readers who do not know it.
Question 7 of 20 · Multiple Choice
A student's report on the salt and temperature experiment (T3) can include one graphic. Which graphic would best help readers compare the results?
Answer: D
The report's results compare three conditions, and a bar graph of the means with a labeled axis shows the comparison at a glance. A shows nothing about the results. B and C could help explain the procedure but do not compare the conditions.
Question 8 of 20 · Multiple Choice
Which set of headings best organizes a lab report on the salt and temperature experiment (T3)?
Answer: A
A follows the order a science reader expects and tells the reader what each section contains. B lists materials rather than parts of the report, C names paragraph types that say nothing about the content, and D is informal and uninformative.
Question 9 of 20 · Multiple Choice
Paragraph 3 of the model text (T1) begins, "Breaking the walls is not enough, because the DNA is still wrapped inside membranes." How does this sentence link paragraph 3 to paragraph 2?
Answer: A
"Breaking the walls" points back to Stage 1, and "because" introduces the reason Stage 2 is needed, which links the sections and shows how they connect. B reverses paragraph 2, C confuses the sentence with paragraph 6, and D ignores that the paragraph goes on to the extraction solution.
Question 10 of 20 · Multiple Choice
Choose the transition that best shows the relationship between these sentences: The soap broke apart the lipid membranes of the cells. ____, the DNA was released into the liquid.
Answer: C
The second sentence states an effect of the first, which "As a result" signals. "In contrast" signals a difference, "For example" introduces an instance of the first idea, and "Similarly" signals a second, parallel idea.
Question 11 of 20 · Multiple Choice
Which revision of The DNA stuff showed up in the alcohol part uses the most precise language?
Answer: D
D names what formed, uses the domain term "precipitated," and says exactly where (the boundary between the layers). A keeps "stuff" and "part," B is vaguer than the original, and C relies on the teacher instead of the observation.
Question 12 of 20 · Multiple Choice
Which sentence is written for the biology teacher's lab report rather than for the family science night handout?
Answer: A
A reports a comparison of the conditions in neutral terms and cites the explanation it fits, which a teacher judging the results expects. B addresses the reader with advice, C uses a comparison chosen for young readers, and D expresses wonder instead of reporting a result; all three suit the handout better.
Question 13 of 20 · Multiple Choice
Which revision of the weak draft's (T2) sentence Then we added the alcohol and the DNA appeared like magic!!! keeps a formal style and an objective tone?
Answer: C
C reports what was observed and where, without exclamation or feeling. A keeps slang ("honestly," "pretty amazing"), B keeps the magic comparison and reports the class's feelings, and D addresses the reader as "you" and claims more than was observed.
Question 14 of 20 · Multiple Choice
A second class repeated the procedure with kiwi fruit (see question 20). Which sentence follows the conventions of the method section of its lab report?
Answer: D
A method section narrates what was done, in the past tense, with quantities and units. A addresses the reader and gives no quantities, B reports opinions, and C is written as commands, which suits a lab manual's procedure but not the narration of an experiment that has already been done.
Question 15 of 20 · Short Answer
Write an extended definition, three or four sentences long, of the word precipitate as the model text (T1) uses it in paragraph 4. Include what happens, why it happens in this procedure, and how it differs from dissolving.
Model answer: "To precipitate is to come out of solution: molecules that were spread invisibly through a liquid gather into a solid that can be seen. In the strawberry procedure, DNA is dissolved in the watery extract, but it 'does not dissolve in alcohol,' so it precipitates where the two layers meet, 'as white, cloudy strands' (T1, paragraph 4). Precipitating is the opposite of dissolving, in which a substance spreads out among the molecules of a liquid and disappears from view." Rubric line: 2 points for a definition that states the process, gives the cause from paragraph 4 and draws the distinction from dissolving; 1 point if one of the three is missing or the cause is wrong.
Question 16 of 20 · Short Answer
The model text (T1) says, "Each stage depends on the one before it." Explain one connection between two stages that supports this sentence, and name one distinction between two terms that the writer makes along the way. Cite paragraphs.
Model answer: Connection: Stage 2 depends on Stage 1, because the cell walls are "too tough for soap to dissolve" (T1, paragraph 2), so the soap can reach the membranes only after mashing has torn the walls open. Distinction: the writer separates DNA that is dissolved, whose "molecules are spread out among the water molecules and cannot be seen," from DNA that precipitates as strands in the alcohol (T1, paragraph 4). Rubric line: 2 points for an accurate connection explained with its reason and a distinction between two terms, both cited; 1 point for one of these.
Question 17 of 20 · Short Answer
Write a different concluding statement for the model text (T1), one or two sentences long, that follows from the explanation and states an implication or the significance of the procedure. Do not repeat the text's last sentence.
Model answer: "Because the procedure yields only a crude extract, its value lies in making an invisible molecule visible, not in testing it: a class that wants to study the DNA itself would need the purifying steps that a genetics laboratory adds (T1, paragraph 5)." Rubric line: 2 points for a conclusion that draws on the explanation (for example, the crude extract or the dependence of the stages) and states an implication or significance; 1 point for a conclusion that only summarizes; 0 for a new topic or general praise of science.
Question 18 of 20 · Short Answer
Revise these sentences from the weak draft (T2) into two or three sentences that show how the steps connect. Use transitions from at least two relationships and vary your sentence structure: "First you smash up the strawberry. Then you put the soap stuff in and smash it more. Then we filtered it."
Model answer: "The strawberry was first mashed in a closed bag, which tore open the stiff cell walls. Once the walls were broken, an extraction solution of water, soap and salt was added so that the soap could dissolve the membranes underneath. The mixture was then filtered, because the seeds and pulp had to be removed before the alcohol was added." Rubric line: 2 points for accurate steps joined by transitions from at least two relationships (sequence and cause, for example), varied sentence openings and structures, precise terms and no "you"; 1 point if the sentences still read as a list.
Question 19 of 20 · Short Answer
The weak draft (T2) says, "The salt is there for flavor I think, or maybe to make it heavier." Rewrite the sentence so that it is accurate, precise and formal, using the model text, and name the paragraph you used.
Model answer: "The salt in the extraction solution provides positive sodium ions, which partly cancel the negative charge along the DNA backbone so that the strands can clump together instead of repelling one another (T1, paragraph 3)." Rubric line: 2 points for the correct role of salt, precise terms (ions, charge), a formal tone and a correct citation; 1 point if the role is correct but vague or informal; 0 if the error remains.
Question 20 of 20 · Short Answer
A second class tried the standard procedure with kiwi fruit instead of strawberries (invented data). Four groups recorded wet masses of 0.21 g, 0.14 g, 0.25 g and 0.16 g. Write two sentences for the results section of a lab report that report the mean and the range with units, in the past tense.
Model answer: "Four groups extracted material from kiwi fruit using the standard procedure. The mean wet mass of the spooled strands was 0.19 g, with individual results ranging from 0.14 g to 0.25 g (invented data)." The mean is (0.21 + 0.14 + 0.25 + 0.16) / 4 = 0.76 / 4 = 0.19 g. Rubric line: 2 points for the correct mean and range with units, past tense and a note that the data are invented; 1 point if the numbers are right but the conventions are not, or the reverse.
0 of 20 answered · 0 correct
06
Frequently Asked Questions
10 Questions
What does WHST.9-10.2 mean?
WHST.9-10.2 means that students in grades 9 and 10 can write informative and explanatory texts about the content of science, history and technical subjects, including accounts of historical events, experiments and technical processes.
Its six parts ask students to introduce and organize the topic to show connections and distinctions, with headings and graphics where useful (a); develop it with relevant, sufficient facts and details (b); link sections with varied transitions and sentence structures (c); use precise, domain-specific vocabulary for the readers (d); keep a formal style and objective tone that follows the discipline's norms (e); and write a conclusion that follows (f).
What is the difference between WHST.9-10.2 and W.9-10.2?
W.9-10.2 is the English-class standard for informative writing, while WHST.9-10.2 applies the same skills to history, science and technical subjects.
The WHST version names the kinds of texts those classes write: the narration of historical events, scientific procedures and experiments, and technical processes. It also asks for a style that fits the discipline and the expertise of likely readers, so a lab report and a history explanation follow different conventions.
Is WHST.9-10.2 taught in science class or in English class?
It is meant for science, history and technical classes, as part of the Common Core literacy standards for those subjects.
English teachers often help with the writing moves, but the content comes from the discipline: a lab, a data set, a historical event or a technical process. Many schools teach it through lab reports, procedure write-ups and short research explanations.
How is explaining a procedure different from listing its steps?
A list of steps tells the reader what to do; an explanation tells the reader why each step works and how the steps depend on one another.
In the strawberry procedure, "add soap" is a step, and "soap breaks apart the lipids of the membranes, which the mashing has exposed" is an explanation. A lab manual needs the steps; an informative text needs both.
Does a lab report count as informative writing under WHST.9-10.2?
Yes: narrating an experiment, what was done and what was found, is one of the text types the standard names.
The method and results sections are informative. The discussion section may also argue for an interpretation, and then the argument standard, WHST.9-10.1, applies as well.
What are the norms and conventions of science writing?
They are the habits science readers expect, which make a report easy to check and repeat.
They include the past tense for what was done, quantities with units, the precise names of materials, observations kept separate from explanations, tables and graphs with titles and labeled axes, and claims no stronger than the evidence. History writing has different norms, such as naming sources and dates.
Do students have to use headings, graphics and multimedia?
No: the standard asks for them "when useful to aiding comprehension," so the writer decides.
Headings help in a report with several sections, a table helps when readers must compare numbers, and a short video clip can show a step that is hard to describe, such as pouring one liquid slowly onto another. Activity 2 on this page practices those choices.
How is WHST.9-10.2 different from WHST.11-12.2?
The grade 11-12 version asks for more complex organization and a more knowledgeable voice.
WHST.11-12.2 asks students to organize complex ideas so that "each new element builds on that which precedes it," to select the most significant facts, to use metaphor, simile and analogy to manage complexity, and to convey a knowledgeable stance. The grade 9-10 standard focuses on connections and distinctions and has a separate part for formal style and objective tone.
Is the strawberry DNA procedure safe for a classroom?
It is widely done in schools, with sensible precautions around the alcohol.
Isopropyl alcohol is highly flammable, irritates the eyes and skin, and is poisonous if swallowed, so use a small amount in a ventilated room away from flames and heat, wear safety goggles, and do not let students taste anything. Chill it in an ice bath or a unit rated for flammable storage, never an ordinary household freezer, and follow your school's rules for storing and disposing of it; this lesson can also be taught from the texts alone, without doing the lab.
How can parents help with explanatory writing in science?
Ask your student to explain not only what they did in a lab, but why each step was needed.
Useful questions are "What problem did that step solve?", "What would have happened without it?" and "How is that different from ...?" These are the connections and distinctions the standard asks students to write.
07
Related Standards
5 standards
These standards connect to WHST.9-10.2: prerequisites to review first, parallel standards at the same level, and next steps that build on it.
Before this lesson
WHST.6-8.2Prerequisite
Write informative texts in science and history that preview and organize a topic
Lesson coming soon
Alongside
RST.9-10.3Parallel
Follow a complex multistep procedure in experiments and technical tasks
