Elementary School Science Quiz: Argue How Plants Grow
20 questions · exam conditions
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Argue How Plants GrowQuestion 1 of 20

A student tries to support the claim "Plants get most materials from soil." Evidence available: tree mass increases while soil mass barely decreases; plants are 93% C, H, O; hydroponics plants grow well without soil; without CO2_2, plants do not grow. Which statement represents the strongest argument based on the evidence?

The claim is supported because plants live in soil, so soil must turn into plant matter.
The claim is refuted because soil changes little, plants are mostly C, H, O, and CO2_2 is required.
The claim is supported because soil lost a tiny amount, showing soil provided most of the mass.
The claim is supported because farmers add fertilizer, proving plants are made mostly of soil.
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Elementary School Science Quiz

Elementary School Science Quiz: Argue How Plants Grow

Practice Argue How Plants Grow in Elementary School Science with focused quiz questions that help you check what you know, review explanations, and build confidence with test-style prompts.

What this quiz covers

This quiz focuses on Argue How Plants Grow, giving you a quick way to practice the rules, question types, and explanations that matter most for Elementary School Science.

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Try each quiz question before looking at the correct answer. Use the explanations to review missed ideas, then come back to similar questions until the pattern feels familiar.

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Question 1

A student tries to support the claim "Plants get most materials from soil." Evidence available: tree mass increases while soil mass barely decreases; plants are 93% C, H, O; hydroponics plants grow well without soil; without CO2_2, plants do not grow. Which statement represents the strongest argument based on the evidence?

  1. The claim is supported because plants live in soil, so soil must turn into plant matter.
  2. The claim is refuted because soil changes little, plants are mostly C, H, O, and CO2_2 is required. (correct answer)
  3. The claim is supported because soil lost a tiny amount, showing soil provided most of the mass.
  4. The claim is supported because farmers add fertilizer, proving plants are made mostly of soil.
Explanation: This question tests the ability to construct arguments using evidence about how plants grow (NGSS 5-LS1-1). Students must evaluate claims, cite relevant evidence, use reasoning to connect evidence to claims, and distinguish strong arguments from weak ones. A scientific argument has three essential components: (1) Claim—a statement about how something works (e.g., 'Plants get materials chiefly from air and water'). (2) Evidence—data, observations, or experiments that test the claim (e.g., Van Helmont's experiment showing tree gained 164 pounds while soil lost only 0.1 pound; chemical analysis showing plants are 93% C, H, O from air and water; hydroponics showing plants grow without soil). (3) Reasoning—explanation of how the evidence supports the claim (e.g., 'If plants got materials from soil, the soil mass would decrease significantly as the plant grows. Since it doesn't, the materials must come from somewhere else—air and water'). Strong arguments use multiple pieces of relevant evidence, connect evidence to claim through logical reasoning, and acknowledge what the evidence actually shows rather than relying on assumptions or opinions. Choice B is correct because it presents a strong argument that uses evidence that directly tests the claim and connects evidence to the claim through clear reasoning, refuting the soil-based claim. Specifically, the evidence about tree mass and soil mass directly tests whether soil provides materials, the composition data shows plants are made of C, H, O from air and water, and multiple independent lines of evidence converge on the same conclusion. This represents effective scientific argumentation. Choice A fails as an argument because it makes a claim without citing evidence, relying on assumption that living in soil means soil turns into plant matter. In scientific argumentation, claims must be supported by relevant evidence, and reasoning must logically connect the evidence to the claim. To help students construct and evaluate arguments: Teach the Claim-Evidence-Reasoning (CER) framework explicitly. Claim: What are you trying to prove? Evidence: What data or observations support it? Reasoning: How does the evidence support the claim? Practice with examples: Weak argument: 'Plants need soil because they grow in soil.' (Claim with no real evidence—correlation not causation). Strong argument: 'Plants get materials chiefly from air and water because: (1) Evidence: Trees gain hundreds of pounds while soil mass barely changes. (2) Reasoning: If soil provided the mass, soil would decrease significantly. (3) Evidence: Plants are 93% C, H, O from air and water, only 7% minerals from soil. (4) Reasoning: The composition shows what plants are made of—mostly elements from air and water. Therefore, most plant matter comes from air and water, not soil.' Evaluate arguments by asking: Is there evidence? Is the evidence relevant to the claim? Does the reasoning connect evidence to claim? Are there multiple pieces of evidence? Do they converge on one conclusion? Watch for: Students who state opinions without evidence, or who cite irrelevant evidence, or who don't explain the connection between evidence and claim. Always require: Claim + Evidence + Reasoning = Complete Argument.

Question 2

Students observe: a plant gains 200 g of mass while the soil loses only 2 g. They also learn plants are 93% C, H, O from air and water and can grow in hydroponics. Which argument is best supported by the evidence?

  1. Most new plant mass comes from soil because any soil loss means soil built the plant.
  2. Most new plant mass comes from air and water because soil loss is tiny and plants are mostly C, H, O. (correct answer)
  3. Most new plant mass comes equally from soil and air because both are around the plant.
  4. Most new plant mass comes from soil because plants look greener when soil has more minerals.
Explanation: This question tests the ability to construct arguments using evidence about how plants grow (NGSS 5-LS1-1). Students must evaluate claims, cite relevant evidence, use reasoning to connect evidence to claims, and distinguish strong arguments from weak ones. A scientific argument has three essential components: (1) Claim—a statement about how something works (e.g., 'Plants get materials chiefly from air and water'). (2) Evidence—data, observations, or experiments that test the claim (e.g., Van Helmont's experiment showing tree gained 164 pounds while soil lost only 0.1 pound; chemical analysis showing plants are 93% C, H, O from air and water; hydroponics showing plants grow without soil). (3) Reasoning—explanation of how the evidence supports the claim (e.g., 'If plants got materials from soil, the soil mass would decrease significantly as the plant grows. Since it doesn't, the materials must come from somewhere else—air and water'). Strong arguments use multiple pieces of relevant evidence, connect evidence to claim through logical reasoning, and acknowledge what the evidence actually shows rather than relying on assumptions or opinions. Choice B is correct because it presents a strong argument that cites multiple relevant pieces of evidence and connects evidence to claim through clear reasoning. Specifically, the evidence about tree mass and soil mass directly tests whether soil provides materials, the composition data shows plants are made of C, H, O from air and water, and multiple independent lines of evidence converge on the same conclusion. This represents effective scientific argumentation. Choice A fails as an argument because it reaches a conclusion that the evidence contradicts. In scientific argumentation, claims must be supported by relevant evidence, and reasoning must logically connect the evidence to the claim. To help students construct and evaluate arguments: Teach the Claim-Evidence-Reasoning (CER) framework explicitly. Claim: What are you trying to prove? Evidence: What data or observations support it? Reasoning: How does the evidence support the claim? Practice with examples: Weak argument: 'Plants need soil because they grow in soil.' (Claim with no real evidence—correlation not causation). Strong argument: 'Plants get materials chiefly from air and water because: (1) Evidence: Trees gain hundreds of pounds while soil mass barely changes. (2) Reasoning: If soil provided the mass, soil would decrease significantly. (3) Evidence: Plants are 93% C, H, O from air and water, only 7% minerals from soil. (4) Reasoning: The composition shows what plants are made of—mostly elements from air and water. Therefore, most plant matter comes from air and water, not soil.' Evaluate arguments by asking: Is there evidence? Is the evidence relevant to the claim? Does the reasoning connect evidence to claim? Are there multiple pieces of evidence? Do they converge on one conclusion? Watch for: Students who state opinions without evidence, or who cite irrelevant evidence, or who don't explain the connection between evidence and claim. Always require: Claim + Evidence + Reasoning = Complete Argument.

Question 3

Students compare evidence about where plant mass comes from. Evidence: soil mass drops only a tiny amount as a plant grows; plants are mostly C, H, O; plants can grow without soil in hydroponics; plants need CO2_2 in air to grow. Based on multiple pieces of evidence, which conclusion is best supported?

  1. Plants get most of their mass from soil because roots take in soil particles as food.
  2. Plants get most of their mass from air and water, while soil provides only small mineral amounts. (correct answer)
  3. Plants get all their mass from water because hydroponics uses water instead of soil.
  4. Plants get equal mass from soil, air, and water because they need all three to survive.
Explanation: This question tests the ability to construct arguments using evidence about how plants grow (NGSS 5-LS1-1). Students must evaluate claims, cite relevant evidence, use reasoning to connect evidence to claims, and distinguish strong arguments from weak ones. A scientific argument has three essential components: (1) Claim—a statement about how something works (e.g., 'Plants get materials chiefly from air and water'). (2) Evidence—data, observations, or experiments that test the claim (e.g., Van Helmont's experiment showing tree gained 164 pounds while soil lost only 0.1 pound; chemical analysis showing plants are 93% C, H, O from air and water; hydroponics showing plants grow without soil). (3) Reasoning—explanation of how the evidence supports the claim (e.g., 'If plants got materials from soil, the soil mass would decrease significantly as the plant grows. Since it doesn't, the materials must come from somewhere else—air and water'). Strong arguments use multiple pieces of relevant evidence, connect evidence to claim through logical reasoning, and acknowledge what the evidence actually shows rather than relying on assumptions or opinions. Choice B is correct because it presents a strong argument that cites multiple relevant pieces of evidence and uses reasoning to connect evidence to the claim. Specifically, the evidence about soil mass, composition, hydroponics, and CO2 directly tests where mass comes from, with multiple independent lines of evidence converging on the same conclusion. This represents effective scientific argumentation. Choice A fails as an argument because it makes a claim without citing evidence, relying on assumption about roots taking soil particles. In scientific argumentation, claims must be supported by relevant evidence, and reasoning must logically connect the evidence to the claim. To help students construct and evaluate arguments: Teach the Claim-Evidence-Reasoning (CER) framework explicitly. Claim: What are you trying to prove? Evidence: What data or observations support it? Reasoning: How does the evidence support the claim? Practice with examples: Weak argument: 'Plants need soil because they grow in soil.' (Claim with no real evidence—correlation not causation). Strong argument: 'Plants get materials chiefly from air and water because: (1) Evidence: Trees gain hundreds of pounds while soil mass barely changes. (2) Reasoning: If soil provided the mass, soil would decrease significantly. (3) Evidence: Plants are 93% C, H, O from air and water, only 7% minerals from soil. (4) Reasoning: The composition shows what plants are made of—mostly elements from air and water. Therefore, most plant matter comes from air and water, not soil.' Evaluate arguments by asking: Is there evidence? Is the evidence relevant to the claim? Does the reasoning connect evidence to claim? Are there multiple pieces of evidence? Do they converge on one conclusion? Watch for: Students who state opinions without evidence, or who cite irrelevant evidence, or who don't explain the connection between evidence and claim. Always require: Claim + Evidence + Reasoning = Complete Argument.

Question 4

A student argues, "Plants get most materials from air and water." Evidence: plants are 93% C, H, O; trees gain lots of mass while soil mass changes very little; hydroponic plants grow without soil. Which statement represents the strongest argument based on this evidence?

  1. The claim is supported because several tests show soil is not the main source of plant mass. (correct answer)
  2. The claim is refuted because roots are in soil, so soil must provide most plant materials.
  3. The claim is supported because plants need minerals, so minerals must be most of the plant.
  4. The claim is refuted because plants grow in soil, and that proves soil makes up plant mass.
Explanation: This question tests the ability to construct arguments using evidence about how plants grow (NGSS 5-LS1-1). Students must evaluate claims, cite relevant evidence, use reasoning to connect evidence to claims, and distinguish strong arguments from weak ones. A scientific argument has three essential components: (1) Claim—a statement about how something works (e.g., 'Plants get materials chiefly from air and water'). (2) Evidence—data, observations, or experiments that test the claim (e.g., Van Helmont's experiment showing tree gained 164 pounds while soil lost only 0.1 pound; chemical analysis showing plants are 93% C, H, O from air and water; hydroponics showing plants grow without soil). (3) Reasoning—explanation of how the evidence supports the claim (e.g., 'If plants got materials from soil, the soil mass would decrease significantly as the plant grows. Since it doesn't, the materials must come from somewhere else—air and water'). Strong arguments use multiple pieces of relevant evidence, connect evidence to claim through logical reasoning, and acknowledge what the evidence actually shows rather than relying on assumptions or opinions. Choice A is correct because it presents a strong argument that uses evidence that directly tests the claim and recognizes what the evidence demonstrates. Specifically, the evidence about tree mass and soil mass directly tests whether soil provides materials, the composition data shows plants are made of C, H, O from air and water, and multiple independent lines of evidence converge on the same conclusion. This represents effective scientific argumentation. Choice B fails as an argument because the evidence cited doesn't actually test the claim (roots in soil doesn't prove soil provides matter). In scientific argumentation, claims must be supported by relevant evidence, and reasoning must logically connect the evidence to the claim. To help students construct and evaluate arguments: Teach the Claim-Evidence-Reasoning (CER) framework explicitly. Claim: What are you trying to prove? Evidence: What data or observations support it? Reasoning: How does the evidence support the claim? Practice with examples: Weak argument: 'Plants need soil because they grow in soil.' (Claim with no real evidence—correlation not causation). Strong argument: 'Plants get materials chiefly from air and water because: (1) Evidence: Trees gain hundreds of pounds while soil mass barely changes. (2) Reasoning: If soil provided the mass, soil would decrease significantly. (3) Evidence: Plants are 93% C, H, O from air and water, only 7% minerals from soil. (4) Reasoning: The composition shows what plants are made of—mostly elements from air and water. Therefore, most plant matter comes from air and water, not soil.' Evaluate arguments by asking: Is there evidence? Is the evidence relevant to the claim? Does the reasoning connect evidence to claim? Are there multiple pieces of evidence? Do they converge on one conclusion? Watch for: Students who state opinions without evidence, or who cite irrelevant evidence, or who don't explain the connection between evidence and claim. Always require: Claim + Evidence + Reasoning = Complete Argument.

Question 5

Three students argue about plant materials. Student A: "Plants get materials from soil because roots are in soil." Student B: "Plants get materials chiefly from air and water," citing composition (93% C, H, O), soil mass staying nearly the same, and hydroponics. Student C: "Plants get materials equally from air, water, and soil." Which student's argument is best supported by evidence?​

  1. Student A, because roots are in soil, so soil must provide most of the plant's mass.
  2. Student C, because plants need all three, so each source must add the same amount of matter.
  3. Student B, because several different tests and data sets all support air and water as main sources. (correct answer)
  4. Student A, because farmers add soil nutrients, which proves plants are mostly made of soil.
Explanation: This question tests the ability to construct arguments using evidence about how plants grow (NGSS 5-LS1-1). Students must evaluate claims, cite relevant evidence, use reasoning to connect evidence to claims, and distinguish strong arguments from weak ones. A scientific argument has three essential components: (1) Claim—a statement about how something works (e.g., 'Plants get materials chiefly from air and water'). (2) Evidence—data, observations, or experiments that test the claim (e.g., Van Helmont's experiment showing tree gained 164 pounds while soil lost only 0.1 pound; chemical analysis showing plants are 93% C, H, O from air and water; hydroponics showing plants grow without soil). (3) Reasoning—explanation of how the evidence supports the claim (e.g., 'If plants got materials from soil, the soil mass would decrease significantly as the plant grows. Since it doesn't, the materials must come from somewhere else—air and water'). Strong arguments use multiple pieces of relevant evidence, connect evidence to claim through logical reasoning, and acknowledge what the evidence actually shows rather than relying on assumptions or opinions. Choice C is correct because Student B presents a strong argument that cites multiple relevant pieces of evidence—composition data (93% C, H, O), soil mass staying nearly the same, and hydroponics success. These different tests all converge on the same conclusion through clear reasoning. Choice A fails because Student A makes a claim without citing real evidence—roots being in soil doesn't prove soil provides mass. To help students construct and evaluate arguments: Teach the Claim-Evidence-Reasoning (CER) framework explicitly. Compare complete arguments (Student B with evidence and reasoning) to incomplete ones (Student A with only a claim). Practice identifying when students cite evidence versus when they state assumptions. Always require all three CER components for a complete scientific argument.

Question 6

Chen says, "Plants get materials for growth chiefly from air and water, not soil." Evidence: chemical tests show plants are 93% C, H, O; a tree gained lots of mass while soil mass barely changed; plants stop growing without CO2_2. Which statement is the strongest argument using this evidence?

  1. The claim is supported because composition and experiments show most plant mass comes from air and water. (correct answer)
  2. The claim is supported because plants grow near soil, so soil must provide most materials.
  3. The claim is refuted because soil is needed, so soil must provide most of the plant's mass.
  4. The claim is refuted because plants need minerals, so minerals must make up most of the plant.
Explanation: This question tests the ability to construct arguments using evidence about how plants grow (NGSS 5-LS1-1). Students must evaluate claims, cite relevant evidence, use reasoning to connect evidence to claims, and distinguish strong arguments from weak ones. A scientific argument has three essential components: (1) Claim—a statement about how something works (e.g., 'Plants get materials chiefly from air and water'). (2) Evidence—data, observations, or experiments that test the claim (e.g., Van Helmont's experiment showing tree gained 164 pounds while soil lost only 0.1 pound; chemical analysis showing plants are 93% C, H, O from air and water; hydroponics showing plants grow without soil). (3) Reasoning—explanation of how the evidence supports the claim (e.g., 'If plants got materials from soil, the soil mass would decrease significantly as the plant grows. Since it doesn't, the materials must come from somewhere else—air and water'). Strong arguments use multiple pieces of relevant evidence, connect evidence to claim through logical reasoning, and acknowledge what the evidence actually shows rather than relying on assumptions or opinions. Choice A is correct because it presents a strong argument that cites multiple relevant pieces of evidence and connects evidence to claim through clear reasoning. Specifically, the evidence about tree mass and soil mass directly tests whether soil provides materials, the composition data shows plants are made of C, H, O from air and water, and multiple independent lines of evidence converge on the same conclusion. This represents effective scientific argumentation. Choice B fails as an argument because the evidence cited doesn't actually test the claim (roots in soil doesn't prove soil provides matter). In scientific argumentation, claims must be supported by relevant evidence, and reasoning must logically connect the evidence to the claim. To help students construct and evaluate arguments: Teach the Claim-Evidence-Reasoning (CER) framework explicitly. Claim: What are you trying to prove? Evidence: What data or observations support it? Reasoning: How does the evidence support the claim? Practice with examples: Weak argument: 'Plants need soil because they grow in soil.' (Claim with no real evidence—correlation not causation). Strong argument: 'Plants get materials chiefly from air and water because: (1) Evidence: Trees gain hundreds of pounds while soil mass barely changes. (2) Reasoning: If soil provided the mass, soil would decrease significantly. (3) Evidence: Plants are 93% C, H, O from air and water, only 7% minerals from soil. (4) Reasoning: The composition shows what plants are made of—mostly elements from air and water. Therefore, most plant matter comes from air and water, not soil.' Evaluate arguments by asking: Is there evidence? Is the evidence relevant to the claim? Does the reasoning connect evidence to claim? Are there multiple pieces of evidence? Do they converge on one conclusion? Watch for: Students who state opinions without evidence, or who cite irrelevant evidence, or who don't explain the connection between evidence and claim. Always require: Claim + Evidence + Reasoning = Complete Argument.

Question 7

Students compare two arguments. Argument 1: Plants get most mass from soil because roots are in soil and fertilizer helps. Argument 2: Plants get most mass from air and water because soil mass changes little, plants are 93% C-H-O, hydroponics works, and CO is needed. Which argument is stronger, and why?

  1. Argument 1, because it matches what we usually see, and plants are often planted in soil outdoors.
  2. Argument 2, because it uses multiple relevant experiments and data that directly test where plant mass comes from. (correct answer)
  3. Argument 1, because fertilizer helps plants grow, so fertilizer must be most of what plants are made of.
  4. Both are equally strong, because each uses at least one fact about plants and both could be true.
Explanation: This question tests the ability to construct arguments using evidence about how plants grow (NGSS 5-LS1-1). Students must evaluate claims, cite relevant evidence, use reasoning to connect evidence to claims, and distinguish strong arguments from weak ones. A scientific argument has three essential components: (1) Claim—a statement about how something works. (2) Evidence—data, observations, or experiments that test the claim. (3) Reasoning—explanation of how the evidence supports the claim. Argument 1 lacks specific evidence (roots in soil is an observation, not data testing the claim) and makes assumptions (fertilizer helps doesn't prove mass source). Argument 2 cites four specific pieces of evidence that directly test where mass comes from: soil mass changes little (testing if soil provides mass), composition is 93% C-H-O (showing what plants are made of), hydroponics works (proving soil isn't necessary), and CO₂ is needed (showing air provides materials). Choice B is correct because Argument 2 uses multiple relevant experiments and data that directly test where plant mass comes from, while Argument 1 relies on observations and assumptions without testing the claim. This demonstrates the difference between evidence-based scientific argumentation and opinion-based claims. Choice A fails because matching what we usually see isn't scientific evidence—many common observations have scientific explanations that aren't obvious (like most plant mass coming from invisible CO₂, not visible soil). To help students construct and evaluate arguments: Teach the difference between observations and evidence that tests claims. Observations: 'Plants grow in soil,' 'Fertilizer helps plants.' Evidence testing mass source: 'Soil mass barely changes as plants grow,' 'Plants are 93% elements from air/water.' Practice evaluating argument strength: Weak = claims without evidence or with irrelevant observations. Strong = claims supported by multiple experiments/data that directly test the claim. Emphasize that scientific arguments require evidence that actually tests what you're trying to prove, not just related observations. Always ask: 'Does this evidence tell us WHERE the mass comes from?'

Question 8

A class tests two setups. Setup 1: plant in soil with normal air grows. Setup 2: plant in good soil but with no CO2_2 in the air does not grow. They also know plants are mostly C, H, O. Based on the evidence, which claim is best supported?

  1. Plants get most materials from soil, because good soil should be enough for growth.
  2. Plants get most materials from air and water, because without CO2_2 plants cannot build much mass. (correct answer)
  3. Plants get equal materials from soil and air, because both are needed for plants to survive.
  4. Plants get most materials from sunlight, because sunlight helps plants grow faster than soil.
Explanation: This question tests the ability to construct arguments using evidence about how plants grow (NGSS 5-LS1-1). Students must evaluate claims, cite relevant evidence, use reasoning to connect evidence to claims, and distinguish strong arguments from weak ones. A scientific argument has three essential components: (1) Claim—a statement about how something works (e.g., 'Plants get materials chiefly from air and water'). (2) Evidence—data, observations, or experiments that test the claim (e.g., Van Helmont's experiment showing tree gained 164 pounds while soil lost only 0.1 pound; chemical analysis showing plants are 93% C, H, O from air and water; hydroponics showing plants grow without soil). (3) Reasoning—explanation of how the evidence supports the claim (e.g., 'If plants got materials from soil, the soil mass would decrease significantly as the plant grows. Since it doesn't, the materials must come from somewhere else—air and water'). Strong arguments use multiple pieces of relevant evidence, connect evidence to claim through logical reasoning, and acknowledge what the evidence actually shows rather than relying on assumptions or opinions. Choice B is correct because it presents a strong argument that uses evidence that directly tests the claim and recognizes what the evidence demonstrates. Specifically, the evidence about tree mass and soil mass directly tests whether soil provides materials, the composition data shows plants are made of C, H, O from air and water, and multiple independent lines of evidence converge on the same conclusion. This represents effective scientific argumentation. Choice A fails as an argument because it makes a claim without citing evidence and relies on opinion or assumption rather than data. In scientific argumentation, claims must be supported by relevant evidence, and reasoning must logically connect the evidence to the claim. To help students construct and evaluate arguments: Teach the Claim-Evidence-Reasoning (CER) framework explicitly. Claim: What are you trying to prove? Evidence: What data or observations support it? Reasoning: How does the evidence support the claim? Practice with examples: Weak argument: 'Plants need soil because they grow in soil.' (Claim with no real evidence—correlation not causation). Strong argument: 'Plants get materials chiefly from air and water because: (1) Evidence: Trees gain hundreds of pounds while soil mass barely changes. (2) Reasoning: If soil provided the mass, soil would decrease significantly. (3) Evidence: Plants are 93% C, H, O from air and water, only 7% minerals from soil. (4) Reasoning: The composition shows what plants are made of—mostly elements from air and water. Therefore, most plant matter comes from air and water, not soil.' Evaluate arguments by asking: Is there evidence? Is the evidence relevant to the claim? Does the reasoning connect evidence to claim? Are there multiple pieces of evidence? Do they converge on one conclusion? Watch for: Students who state opinions without evidence, or who cite irrelevant evidence, or who don't explain the connection between evidence and claim. Always require: Claim + Evidence + Reasoning = Complete Argument.

Question 9

A farmer claims, "More fertilizer means more growth because fertilizer provides the materials plants are made of." Evidence: high fertilizer plants were 20% larger; no fertilizer plants were medium and pale; both got same water, air, and sunlight; both groups were 93% C, H, O and 7% minerals. Which statement is the strongest evidence-based argument?

  1. The farmer is correct, because bigger plants prove fertilizer makes up most of plant mass.
  2. The farmer is mostly incorrect, because plants are mostly C, H, O from air and water, not fertilizer. (correct answer)
  3. The farmer is correct, because plants need soil, so soil minerals must be most of the plant.
  4. The farmer is mostly incorrect, because sunlight is the only thing plants need to grow.
Explanation: This question tests the ability to construct arguments using evidence about how plants grow (NGSS 5-LS1-1). Students must evaluate claims, cite relevant evidence, use reasoning to connect evidence to claims, and distinguish strong arguments from weak ones. A scientific argument has three essential components: (1) Claim—a statement about how something works (e.g., 'Plants get materials chiefly from air and water'). (2) Evidence—data, observations, or experiments that test the claim (e.g., Van Helmont's experiment showing tree gained 164 pounds while soil lost only 0.1 pound; chemical analysis showing plants are 93% C, H, O from air and water; hydroponics showing plants grow without soil). (3) Reasoning—explanation of how the evidence supports the claim (e.g., 'If plants got materials from soil, the soil mass would decrease significantly as the plant grows. Since it doesn't, the materials must come from somewhere else—air and water'). Strong arguments use multiple pieces of relevant evidence, connect evidence to claim through logical reasoning, and acknowledge what the evidence actually shows rather than relying on assumptions or opinions. Choice B is correct because it presents a strong argument that recognizes what the evidence demonstrates and connects evidence to claim through clear reasoning. Specifically, the evidence about tree mass and soil mass directly tests whether soil provides materials, the composition data shows plants are made of C, H, O from air and water, and multiple independent lines of evidence converge on the same conclusion. This represents effective scientific argumentation. Choice A fails as an argument because it reaches a conclusion that the evidence contradicts. In scientific argumentation, claims must be supported by relevant evidence, and reasoning must logically connect the evidence to the claim. To help students construct and evaluate arguments: Teach the Claim-Evidence-Reasoning (CER) framework explicitly. Claim: What are you trying to prove? Evidence: What data or observations support it? Reasoning: How does the evidence support the claim? Practice with examples: Weak argument: 'Plants need soil because they grow in soil.' (Claim with no real evidence—correlation not causation). Strong argument: 'Plants get materials chiefly from air and water because: (1) Evidence: Trees gain hundreds of pounds while soil mass barely changes. (2) Reasoning: If soil provided the mass, soil would decrease significantly. (3) Evidence: Plants are 93% C, H, O from air and water, only 7% minerals from soil. (4) Reasoning: The composition shows what plants are made of—mostly elements from air and water. Therefore, most plant matter comes from air and water, not soil.' Evaluate arguments by asking: Is there evidence? Is the evidence relevant to the claim? Does the reasoning connect evidence to claim? Are there multiple pieces of evidence? Do they converge on one conclusion? Watch for: Students who state opinions without evidence, or who cite irrelevant evidence, or who don't explain the connection between evidence and claim. Always require: Claim + Evidence + Reasoning = Complete Argument.

Question 10

Read two arguments. Argument 1: "Plants get most mass from soil," because plants grow in soil and roots are in soil. Argument 2: "Plants get most mass from air and water," because trees gain lots of mass while soil stays nearly the same, plants are 93% C, H, O, hydroponics works, and removing CO2_2 stops growth. What makes Argument 2 stronger than Argument 1?

  1. It uses several relevant experiments and data, and explains how they support the claim. (correct answer)
  2. It is stronger because it repeats the claim more times and sounds more confident.
  3. It is stronger because it focuses on roots being in soil, which proves soil makes plants.
  4. It is stronger because it ignores CO2_2 results and only talks about hydroponics.
Explanation: This question tests the ability to construct arguments using evidence about how plants grow (NGSS 5-LS1-1). Students must evaluate claims, cite relevant evidence, use reasoning to connect evidence to claims, and distinguish strong arguments from weak ones. A scientific argument has three essential components: (1) Claim—a statement about how something works (e.g., 'Plants get materials chiefly from air and water'). (2) Evidence—data, observations, or experiments that test the claim (e.g., Van Helmont's experiment showing tree gained 164 pounds while soil lost only 0.1 pound; chemical analysis showing plants are 93% C, H, O from air and water; hydroponics showing plants grow without soil). (3) Reasoning—explanation of how the evidence supports the claim (e.g., 'If plants got materials from soil, the soil mass would decrease significantly as the plant grows. Since it doesn't, the materials must come from somewhere else—air and water'). Strong arguments use multiple pieces of relevant evidence, connect evidence to claim through logical reasoning, and acknowledge what the evidence actually shows rather than relying on assumptions or opinions. Choice A is correct because it presents a strong argument that cites multiple relevant pieces of evidence and uses reasoning to connect evidence to claims. Specifically, the evidence about tree mass and soil mass directly tests whether soil provides materials, the composition data shows plants are made of C, H, O from air and water, and multiple independent lines of evidence converge on the same conclusion. This represents effective scientific argumentation. Choice C fails as an argument because the evidence cited doesn't actually test the claim (roots in soil doesn't prove soil provides matter). In scientific argumentation, claims must be supported by relevant evidence, and reasoning must logically connect the evidence to the claim. To help students construct and evaluate arguments: Teach the Claim-Evidence-Reasoning (CER) framework explicitly. Claim: What are you trying to prove? Evidence: What data or observations support it? Reasoning: How does the evidence support the claim? Practice with examples: Weak argument: 'Plants need soil because they grow in soil.' (Claim with no real evidence—correlation not causation). Strong argument: 'Plants get materials chiefly from air and water because: (1) Evidence: Trees gain hundreds of pounds while soil mass barely changes. (2) Reasoning: If soil provided the mass, soil would decrease significantly. (3) Evidence: Plants are 93% C, H, O from air and water, only 7% minerals from soil. (4) Reasoning: The composition shows what plants are made of—mostly elements from air and water. Therefore, most plant matter comes from air and water, not soil.' Evaluate arguments by asking: Is there evidence? Is the evidence relevant to the claim? Does the reasoning connect evidence to claim? Are there multiple pieces of evidence? Do they converge on one conclusion? Watch for: Students who state opinions without evidence, or who cite irrelevant evidence, or who don't explain the connection between evidence and claim. Always require: Claim + Evidence + Reasoning = Complete Argument.

Question 11

Three students debate plant growth. Student A: "Plants get materials from soil because roots grow in soil." Student B: "Plants get materials chiefly from air and water," citing: plants are mostly C, H, O; soil mass hardly decreases as plants grow; plants grow in hydroponics. Student C: "Plants get materials equally from soil, water, and air." Which student's argument is best supported by evidence?

  1. Student A, because roots are in soil, so soil must provide most of the plant's mass.
  2. Student C, because plants need all three, so each source must add equal plant mass.
  3. Student B, because multiple experiments and composition data point to air and water as main sources. (correct answer)
  4. Student A, because farmers add minerals to soil, proving soil makes up most plant matter.
Explanation: This question tests the ability to construct arguments using evidence about how plants grow (NGSS 5-LS1-1). Students must evaluate claims, cite relevant evidence, use reasoning to connect evidence to claims, and distinguish strong arguments from weak ones. A scientific argument has three essential components: (1) Claim—a statement about how something works (e.g., 'Plants get materials chiefly from air and water'). (2) Evidence—data, observations, or experiments that test the claim (e.g., Van Helmont's experiment showing tree gained 164 pounds while soil lost only 0.1 pound; chemical analysis showing plants are 93% C, H, O from air and water; hydroponics showing plants grow without soil). (3) Reasoning—explanation of how the evidence supports the claim (e.g., 'If plants got materials from soil, the soil mass would decrease significantly as the plant grows. Since it doesn't, the materials must come from somewhere else—air and water'). Strong arguments use multiple pieces of relevant evidence, connect evidence to claim through logical reasoning, and acknowledge what the evidence actually shows rather than relying on assumptions or opinions. Choice C is correct because it presents a strong argument that cites multiple relevant pieces of evidence and recognizes what the evidence demonstrates. Specifically, the evidence about tree mass and soil mass directly tests whether soil provides materials, the composition data shows plants are made of C, H, O from air and water, and multiple independent lines of evidence converge on the same conclusion. This represents effective scientific argumentation. Choice A fails as an argument because the evidence cited doesn't actually test the claim (roots in soil doesn't prove soil provides matter). In scientific argumentation, claims must be supported by relevant evidence, and reasoning must logically connect the evidence to the claim. To help students construct and evaluate arguments: Teach the Claim-Evidence-Reasoning (CER) framework explicitly. Claim: What are you trying to prove? Evidence: What data or observations support it? Reasoning: How does the evidence support the claim? Practice with examples: Weak argument: 'Plants need soil because they grow in soil.' (Claim with no real evidence—correlation not causation). Strong argument: 'Plants get materials chiefly from air and water because: (1) Evidence: Trees gain hundreds of pounds while soil mass barely changes. (2) Reasoning: If soil provided the mass, soil would decrease significantly. (3) Evidence: Plants are 93% C, H, O from air and water, only 7% minerals from soil. (4) Reasoning: The composition shows what plants are made of—mostly elements from air and water. Therefore, most plant matter comes from air and water, not soil.' Evaluate arguments by asking: Is there evidence? Is the evidence relevant to the claim? Does the reasoning connect evidence to claim? Are there multiple pieces of evidence? Do they converge on one conclusion? Watch for: Students who state opinions without evidence, or who cite irrelevant evidence, or who don't explain the connection between evidence and claim. Always require: Claim + Evidence + Reasoning = Complete Argument.

Question 12

A farmer claims, More fertilizer makes plants grow more because fertilizer provides what plants are made of. Evidence: high-fertilizer plants were 20% larger; no-fertilizer plants were smaller; both got same air, water, and sunlight; both plants were 93% C, H, O and 7% minerals. Which statement represents the strongest argument based on the evidence?

  1. The farmer is correct, because bigger plants prove fertilizer is the main material plants are made from.
  2. The farmer is partly correct, because minerals help growth, but most plant mass is still from air and water. (correct answer)
  3. The farmer is wrong, because plants do not need minerals at all, only soil and sunlight.
  4. The farmer is correct, because plants grow in soil, so soil must provide nearly all their mass.
Explanation: This question tests the ability to construct arguments using evidence about how plants grow (NGSS 5-LS1-1). Students must evaluate claims, cite relevant evidence, use reasoning to connect evidence to claims, and distinguish strong arguments from weak ones. A scientific argument has three essential components: (1) Claim—a statement about how something works (e.g., 'Fertilizer provides what plants are made of'). (2) Evidence—data, observations, or experiments that test the claim (e.g., fertilized plants were 20% larger; both plant groups were 93% C, H, O and only 7% minerals). (3) Reasoning—explanation of how the evidence supports the claim (e.g., 'While fertilizer helps plants grow larger, the composition data shows plants are 93% C, H, O from air/water and only 7% minerals. Therefore, fertilizer provides important minerals but not most of what plants are made of'). Strong arguments acknowledge what the evidence actually shows rather than overstating conclusions. Choice B is correct because it presents a nuanced argument that accurately interprets the evidence—the farmer is partly correct that minerals help growth (20% larger), but most plant mass (93%) still comes from air and water, not from the fertilizer minerals. This represents effective scientific argumentation that avoids overgeneralization. Choice A fails as an argument because it reaches a conclusion that the evidence contradicts—being 20% larger doesn't prove fertilizer is the main material, especially when composition data shows plants are only 7% minerals. In scientific argumentation, conclusions must match what the evidence actually demonstrates. To help students construct and evaluate arguments: Teach the Claim-Evidence-Reasoning (CER) framework with emphasis on proportional thinking. Practice with examples that require nuanced interpretation: 'Fertilizer helps growth' (supported) vs. 'Fertilizer is what plants are mainly made of' (not supported by 93/7 ratio). Help students distinguish between 'helps growth' and 'provides mass'—minerals are like vitamins for humans: essential in small amounts but not the main building material. Evaluate arguments by asking: Does the conclusion match the scale of the evidence? A 20% size difference doesn't explain where 93% of mass comes from. Always require complete reasoning that addresses all the evidence, not just selected parts.

Question 13

Your teacher asks you to build an argument that plants get materials chiefly from air and water. Evidence: soil mass dropped 2 g while plant mass rose 200 g; plants are 93% C, H, O; hydroponics works; without CO plants dont grow. Which statement is the strongest argument based on the evidence?

  1. Plants get most materials from soil because they grow in soil and roots absorb things from the ground.
  2. Plants get most materials from air and water because mass and composition data, hydroponics, and CO tests all support it. (correct answer)
  3. Plants get most materials from soil because fertilizer makes leaves greener and plants look healthier.
  4. Plants get equal materials from soil, air, and water because they need all three to survive.
Explanation: This question tests the ability to construct arguments using evidence about how plants grow (NGSS 5-LS1-1). Students must evaluate claims, cite relevant evidence, use reasoning to connect evidence to claims, and distinguish strong arguments from weak ones. A scientific argument has three essential components: (1) Claim—a statement about how something works (e.g., 'Plants get materials chiefly from air and water'). (2) Evidence—data, observations, or experiments that test the claim (e.g., soil mass dropped 2 g while plant mass rose 200 g; plants are 93% C, H, O; hydroponics works; without CO₂ plants don't grow). (3) Reasoning—explanation of how the evidence supports the claim (e.g., 'If plants got materials from soil, the soil mass would decrease by roughly the same amount the plant gains. Since soil lost only 2 g while plant gained 200 g, the other 198 g must come from air and water'). Strong arguments use multiple pieces of relevant evidence, connect evidence to claim through logical reasoning, and cite specific data rather than general observations. Choice B is correct because it presents a strong argument that cites all four pieces of evidence provided and uses clear reasoning to connect them to the claim. The mass data, composition data, hydroponics evidence, and CO₂ requirement all converge to support that plants get most materials from air and water. This represents effective scientific argumentation with complete CER structure. Choice A fails as an argument because it makes a claim without citing the specific evidence provided—saying plants grow in soil and roots absorb things is a general observation, not use of the given experimental data. In scientific argumentation, students must use the evidence provided to support their claims. To help students construct and evaluate arguments: Teach the Claim-Evidence-Reasoning (CER) framework explicitly, emphasizing the need to cite specific evidence. Model strong arguments: 'Plants get materials chiefly from air and water because: (1) Evidence: Plant gained 200 g while soil lost only 2 g. (2) Reasoning: The 198 g difference must come from elsewhere. (3) Evidence: Plants are 93% C, H, O. (4) Reasoning: These elements come from CO₂ and H₂O, not soil minerals. (5) Evidence: Hydroponics works. (6) Reasoning: This proves soil isn't necessary for mass. Therefore, air and water provide most plant material.' Always require students to cite the specific evidence given, not general knowledge.

Question 14

In class, Jamal claims plants get most growth material from soil. Evidence: a tree gained 164 lb while soil lost 0.1 lb; plants are 93% C, H, O from air/water; hydroponics plants grow without soil; without CO plants dont grow. Which argument is best supported by the evidence?

  1. Plants get most materials from soil because roots are in soil and farmers add fertilizer.
  2. Plants get materials equally from soil, air, and water because they need all three to live.
  3. Plants get most materials from air and water because soil barely changes, plants are mostly C-H-O, and hydroponics works. (correct answer)
  4. Plants get most materials from soil because the tree gained mass while the soil changed a little.
Explanation: This question tests the ability to construct arguments using evidence about how plants grow (NGSS 5-LS1-1). Students must evaluate claims, cite relevant evidence, use reasoning to connect evidence to claims, and distinguish strong arguments from weak ones. A scientific argument has three essential components: (1) Claim—a statement about how something works (e.g., 'Plants get materials chiefly from air and water'). (2) Evidence—data, observations, or experiments that test the claim (e.g., Van Helmont's experiment showing tree gained 164 pounds while soil lost only 0.1 pound; chemical analysis showing plants are 93% C, H, O from air and water; hydroponics showing plants grow without soil). (3) Reasoning—explanation of how the evidence supports the claim (e.g., 'If plants got materials from soil, the soil mass would decrease significantly as the plant grows. Since it doesn't, the materials must come from somewhere else—air and water'). Strong arguments use multiple pieces of relevant evidence, connect evidence to claim through logical reasoning, and acknowledge what the evidence actually shows rather than relying on assumptions or opinions. Choice C is correct because it presents a strong argument that cites multiple relevant pieces of evidence and connects evidence to claim through clear reasoning. Specifically, the evidence about tree mass and soil mass directly tests whether soil provides materials, the composition data shows plants are made of C, H, O from air and water, and multiple independent lines of evidence converge on the same conclusion. This represents effective scientific argumentation. Choice A fails as an argument because it relies on opinion or assumption rather than data—just because roots are in soil doesn't prove soil provides the mass, and the evidence actually contradicts this claim. In scientific argumentation, claims must be supported by relevant evidence, and reasoning must logically connect the evidence to the claim. To help students construct and evaluate arguments: Teach the Claim-Evidence-Reasoning (CER) framework explicitly. Practice with examples: Weak argument: 'Plants need soil because they grow in soil.' (Claim with no real evidence—correlation not causation). Strong argument: 'Plants get materials chiefly from air and water because: (1) Evidence: Trees gain hundreds of pounds while soil mass barely changes. (2) Reasoning: If soil provided the mass, soil would decrease significantly. (3) Evidence: Plants are 93% C, H, O from air and water, only 7% minerals from soil. (4) Reasoning: The composition shows what plants are made of—mostly elements from air and water. Therefore, most plant matter comes from air and water, not soil.'

Question 15

Two students debate plant growth. Jamal says plants are mostly made of soil; Sofia says plants are mostly made of air and water. Evidence: soil mass stayed nearly the same as a tree gained 500 lb; plants are 45% carbon from CO; hydroponics works; minerals are only a small part. Which argument is better supported by the evidence?

  1. Sofia is supported because carbon comes from CO, hydroponics works, and soil mass stays nearly the same. (correct answer)
  2. Jamal is supported because plants grow in soil and their roots touch soil every day.
  3. Jamal is supported because fertilizer is added to soil, so soil must be most of the plant.
  4. Both are equally supported because plants need soil, water, and air, so each provides the same amount.
Explanation: This question tests the ability to construct arguments using evidence about how plants grow (NGSS 5-LS1-1). Students must evaluate claims, cite relevant evidence, use reasoning to connect evidence to claims, and distinguish strong arguments from weak ones. A scientific argument has three essential components: (1) Claim—a statement about how something works (e.g., 'Plants get materials chiefly from air and water'). (2) Evidence—data, observations, or experiments that test the claim (e.g., Van Helmont's experiment showing tree gained 500 pounds while soil mass stayed nearly the same; chemical analysis showing plants are 45% carbon from CO₂; hydroponics showing plants grow without soil). (3) Reasoning—explanation of how the evidence supports the claim (e.g., 'If plants got materials from soil, the soil mass would decrease significantly as the plant grows. Since it doesn't, the materials must come from somewhere else—air and water'). Strong arguments use multiple pieces of relevant evidence, connect evidence to claim through logical reasoning, and acknowledge what the evidence actually shows rather than relying on assumptions or opinions. Choice A is correct because Sofia's argument cites multiple relevant pieces of evidence that directly test the claim about where plant materials come from. Specifically, the evidence about carbon coming from CO₂, hydroponics working without soil, and soil mass staying nearly the same all converge to support that plants get materials chiefly from air and water. This represents effective scientific argumentation. Choice B fails as an argument because the evidence cited doesn't actually test the claim—roots touching soil doesn't prove soil provides matter, it's just a correlation without causation. In scientific argumentation, claims must be supported by relevant evidence, and reasoning must logically connect the evidence to the claim. To help students construct and evaluate arguments: Teach the Claim-Evidence-Reasoning (CER) framework explicitly. Practice evaluating arguments by asking: Is there evidence? Is the evidence relevant to the claim? Does the reasoning connect evidence to claim? Are there multiple pieces of evidence? Do they converge on one conclusion? Watch for students who state opinions without evidence, or who cite irrelevant evidence, or who don't explain the connection between evidence and claim. Always require: Claim + Evidence + Reasoning = Complete Argument.

Question 16

Three students give arguments. A: Plants get materials from soil because roots are in soil. B: Plants get materials chiefly from air and water. C: Plants get equal materials from soil, air, and water. Evidence: plants are 93% C, H, O; soil mass doesnt drop much as plants grow; hydroponics works; without CO plants dont grow. Which students argument is best supported by evidence?

  1. Student A, because roots are in soil, so soil must provide most of the plants mass.
  2. Student C, because plants need soil, water, and air, so each must add equal plant material.
  3. Student B, because composition, soil-mass data, hydroponics, and CO tests all point to air and water. (correct answer)
  4. Student A, because fertilizer helps plants grow, proving soil is what plants are mostly made of.
Explanation: This question tests the ability to construct arguments using evidence about how plants grow (NGSS 5-LS1-1). Students must evaluate claims, cite relevant evidence, use reasoning to connect evidence to claims, and distinguish strong arguments from weak ones. A scientific argument has three essential components: (1) Claim—a statement about how something works (e.g., 'Plants get materials chiefly from air and water'). (2) Evidence—data, observations, or experiments that test the claim (e.g., chemical analysis showing plants are 93% C, H, O from air and water; Van Helmont's experiment showing soil mass doesn't drop much as plants grow; hydroponics showing plants grow without soil; CO₂ experiments showing plants don't grow without CO₂). (3) Reasoning—explanation of how the evidence supports the claim (e.g., 'If plants got materials from soil, the soil mass would decrease significantly as the plant grows. Since it doesn't, the materials must come from somewhere else—air and water'). Strong arguments use multiple pieces of relevant evidence, connect evidence to claim through logical reasoning, and acknowledge what the evidence actually shows rather than relying on assumptions or opinions. Choice C is correct because Student B's argument is supported by multiple converging lines of evidence: composition data shows plants are mostly C, H, O from air and water; soil-mass data shows soil doesn't provide the mass; hydroponics proves plants can grow without soil; and CO₂ tests show air is essential for growth. This represents effective scientific argumentation with all three CER components. Choice A fails as an argument because it makes a claim without citing evidence—just stating that roots are in soil doesn't prove soil provides mass, it's an assumption without data support. In scientific argumentation, claims must be supported by relevant evidence, and reasoning must logically connect the evidence to the claim. To help students construct and evaluate arguments: Teach the Claim-Evidence-Reasoning (CER) framework explicitly. Claim: What are you trying to prove? Evidence: What data or observations support it? Reasoning: How does the evidence support the claim? Practice with examples showing the difference between weak arguments (claims without evidence or with irrelevant evidence) and strong arguments (claims supported by multiple relevant pieces of evidence with clear reasoning). Evaluate arguments by checking: Does the argument have all three components? Is the evidence relevant and sufficient? Does the reasoning logically connect evidence to claim?

Question 17

Chen writes: Plants get materials chiefly from air and water. Evidence: plants are 93% C, H, O; a tree gained 164 lb while soil lost 0.1 lb; hydroponics plants grow well; removing CO stops growth. Which statement best evaluates Chens argument using evidence and reasoning?

  1. It is strong, because several experiments and composition data all support the claim and explain the small soil change. (correct answer)
  2. It is weak, because it does not mention that roots are in soil, which is the only evidence that matters.
  3. It is strong, because plants grow taller in soil than in water, proving soil gives most of their mass.
  4. It is weak, because soil lost 0.1 lb, which proves soil provided almost all of the 164 lb gain.
Explanation: This question tests the ability to construct arguments using evidence about how plants grow (NGSS 5-LS1-1). Students must evaluate claims, cite relevant evidence, use reasoning to connect evidence to claims, and distinguish strong arguments from weak ones. A scientific argument has three essential components: (1) Claim—Chen states 'Plants get materials chiefly from air and water.' (2) Evidence—Chen cites four pieces: plants are 93% C, H, O; tree gained 164 lb while soil lost 0.1 lb; hydroponics plants grow well; removing CO₂ stops growth. (3) Reasoning—These data show: composition reveals what plants are made of (mostly air/water elements); mass comparison shows soil can't account for plant mass; hydroponics proves soil isn't necessary; CO₂ requirement confirms air provides essential materials. Each piece of evidence directly tests the claim, and all converge on the same conclusion. Choice A is correct because Chen's argument includes several experiments and composition data that all support the claim, and the reasoning explains why the small soil change (0.1 lb loss) makes sense—soil provides only minerals (7% of plant mass), not the main building materials. This represents exemplary scientific argumentation. Choice D fails because it misinterprets the evidence—losing 0.1 lb of soil cannot provide 164 lb of plant mass; this evidence actually supports Chen's claim that materials come from elsewhere (air and water). In scientific argumentation, evidence must be interpreted correctly. To help students construct and evaluate arguments: Model complete CER arguments like Chen's, showing how multiple lines of evidence strengthen claims. Practice identifying convergent evidence—when different experiments all point to the same conclusion, the argument is very strong. Teach correct interpretation of data: If soil lost 0.1 lb and plant gained 164 lb, where did the other 163.9 lb come from? Help students see that strong arguments acknowledge and explain apparent contradictions (why does soil lose any mass? Because it provides the 7% minerals). Evaluate arguments using a checklist: Claim stated? Evidence cited? Evidence relevant? Reasoning connects evidence to claim? Multiple evidence sources? Convergent conclusions?

Question 18

Maya must support the claim "Plants get materials chiefly from air and water, not soil." Evidence: plant mass increased 200 g while soil decreased 2 g; plants are 93% C, H, O from CO2_2 and H2_2O; hydroponic plants grow just as large; plants without CO2_2 do not grow even with perfect soil. Which statement represents the strongest argument based on the evidence?

  1. Plants are made mostly from soil because they grow in soil and farmers improve soil.
  2. Plants are made mostly from air and water because soil mass changes little and CO2_2 is required. (correct answer)
  3. Plants are made mostly from soil because the soil decreased 2 g, so soil provided most mass.
  4. Plants are made equally from soil and air because both are needed for plants to survive.
Explanation: This question tests the ability to construct arguments using evidence about how plants grow (NGSS 5-LS1-1). Students must evaluate claims, cite relevant evidence, use reasoning to connect evidence to claims, and distinguish strong arguments from weak ones. A scientific argument has three essential components: (1) Claim—a statement about how something works (e.g., 'Plants get materials chiefly from air and water'). (2) Evidence—data, observations, or experiments that test the claim (e.g., Van Helmont's experiment showing tree gained 164 pounds while soil lost only 0.1 pound; chemical analysis showing plants are 93% C, H, O from air and water; hydroponics showing plants grow without soil). (3) Reasoning—explanation of how the evidence supports the claim (e.g., 'If plants got materials from soil, the soil mass would decrease significantly as the plant grows. Since it doesn't, the materials must come from somewhere else—air and water'). Strong arguments use multiple pieces of relevant evidence, connect evidence to claim through logical reasoning, and acknowledge what the evidence actually shows rather than relying on assumptions or opinions. Choice B is correct because it presents a strong argument that uses evidence that directly tests the claim and connects evidence to claim through clear reasoning. Specifically, the evidence about tree mass and soil mass directly tests whether soil provides materials, the composition data shows plants are made of C, H, O from air and water, and multiple independent lines of evidence converge on the same conclusion. This represents effective scientific argumentation. Choice C fails as an argument because it reaches a conclusion that the evidence contradicts. In scientific argumentation, claims must be supported by relevant evidence, and reasoning must logically connect the evidence to the claim. To help students construct and evaluate arguments: Teach the Claim-Evidence-Reasoning (CER) framework explicitly. Claim: What are you trying to prove? Evidence: What data or observations support it? Reasoning: How does the evidence support the claim? Practice with examples: Weak argument: 'Plants need soil because they grow in soil.' (Claim with no real evidence—correlation not causation). Strong argument: 'Plants get materials chiefly from air and water because: (1) Evidence: Trees gain hundreds of pounds while soil mass barely changes. (2) Reasoning: If soil provided the mass, soil would decrease significantly. (3) Evidence: Plants are 93% C, H, O from air and water, only 7% minerals from soil. (4) Reasoning: The composition shows what plants are made of—mostly elements from air and water. Therefore, most plant matter comes from air and water, not soil.' Evaluate arguments by asking: Is there evidence? Is the evidence relevant to the claim? Does the reasoning connect evidence to claim? Are there multiple pieces of evidence? Do they converge on one conclusion? Watch for: Students who state opinions without evidence, or who cite irrelevant evidence, or who don't explain the connection between evidence and claim. Always require: Claim + Evidence + Reasoning = Complete Argument.

Question 19

A class tests plant growth with and without CO2_2. Plants with good soil, water, and light did not grow when CO2_2 was removed; plants with normal air grew well. Which piece of reasoning best supports the claim that plants get materials chiefly from air and water?

  1. Because plants need CO2_2 to grow, some plant matter must come from air, not only soil. (correct answer)
  2. Because soil is heavy, it must be the main source of plant mass even if CO2_2 is missing.
  3. Because plants are green, they must be made mostly of minerals found in soil.
  4. Because roots touch soil, soil must provide most materials, and air is less important.
Explanation: This question tests the ability to construct arguments using evidence about how plants grow (NGSS 5-LS1-1). Students must evaluate claims, cite relevant evidence, use reasoning to connect evidence to claims, and distinguish strong arguments from weak ones. A scientific argument has three essential components: (1) Claim—a statement about how something works (e.g., 'Plants get materials chiefly from air and water'). (2) Evidence—data, observations, or experiments that test the claim (e.g., Van Helmont's experiment showing tree gained 164 pounds while soil lost only 0.1 pound; chemical analysis showing plants are 93% C, H, O from air and water; hydroponics showing plants grow without soil). (3) Reasoning—explanation of how the evidence supports the claim (e.g., 'If plants got materials from soil, the soil mass would decrease significantly as the plant grows. Since it doesn't, the materials must come from somewhere else—air and water'). Strong arguments use multiple pieces of relevant evidence, connect evidence to claim through logical reasoning, and acknowledge what the evidence actually shows rather than relying on assumptions or opinions. Choice A is correct because it presents a strong argument that uses evidence that directly tests the claim and connects evidence to the claim through clear reasoning, recognizing that CO2 is required for growth. Specifically, the evidence about no growth without CO2 directly tests whether air provides materials, and this line of evidence supports the conclusion. This represents effective scientific argumentation. Choice D fails as an argument because the evidence cited doesn't actually test the claim (roots touching soil doesn't prove soil provides most matter), and it relies on assumption. In scientific argumentation, claims must be supported by relevant evidence, and reasoning must logically connect the evidence to the claim. To help students construct and evaluate arguments: Teach the Claim-Evidence-Reasoning (CER) framework explicitly. Claim: What are you trying to prove? Evidence: What data or observations support it? Reasoning: How does the evidence support the claim? Practice with examples: Weak argument: 'Plants need soil because they grow in soil.' (Claim with no real evidence—correlation not causation). Strong argument: 'Plants get materials chiefly from air and water because: (1) Evidence: Trees gain hundreds of pounds while soil mass barely changes. (2) Reasoning: If soil provided the mass, soil would decrease significantly. (3) Evidence: Plants are 93% C, H, O from air and water, only 7% minerals from soil. (4) Reasoning: The composition shows what plants are made of—mostly elements from air and water. Therefore, most plant matter comes from air and water, not soil.' Evaluate arguments by asking: Is there evidence? Is the evidence relevant to the claim? Does the reasoning connect evidence to claim? Are there multiple pieces of evidence? Do they converge on one conclusion? Watch for: Students who state opinions without evidence, or who cite irrelevant evidence, or who don't explain the connection between evidence and claim. Always require: Claim + Evidence + Reasoning = Complete Argument.

Question 20

In a CO experiment, one plant had good soil, water, and light but no CO and did not grow. Another plant had the same soil, water, light, and normal air and did grow. How does this evidence affect the claim Plants get most of their growth material from soil?

  1. It supports the claim, because soil was present in both groups, so soil must be the main material source.
  2. It refutes the claim, because without CO plants cant grow even with good soil, showing air matters for mass. (correct answer)
  3. It proves soil is unneeded, because plants can grow with no soil if they have CO and sunlight.
  4. It shows all sources are equal, because both plants had soil, water, and light, so each adds the same mass.
Explanation: This question tests the ability to construct arguments using evidence about how plants grow (NGSS 5-LS1-1). Students must evaluate claims, cite relevant evidence, use reasoning to connect evidence to claims, and distinguish strong arguments from weak ones. A scientific argument has three essential components: (1) Claim—a statement about how something works (e.g., 'Plants get most of their growth material from soil'). (2) Evidence—data, observations, or experiments that test the claim (e.g., CO₂ experiment where plant with no CO₂ didn't grow despite having good soil, water, and light). (3) Reasoning—explanation of how the evidence supports or refutes the claim (e.g., 'If soil provided most growth material, the plant should have grown with good soil even without CO₂. Since it didn't grow without CO₂ but did with CO₂, this shows air (specifically CO₂) is essential for providing growth material'). Strong arguments recognize what controlled experiments actually demonstrate about causation. Choice B is correct because it accurately interprets the experimental evidence—the plant's failure to grow without CO₂, despite having good soil, directly refutes the claim that soil provides most growth material and shows that air (CO₂) is essential for mass accumulation. This represents effective scientific reasoning from a controlled experiment. Choice A fails as an argument because it misinterprets the evidence—the presence of soil in both groups doesn't support soil as the main material source; rather, the experiment shows CO₂ is the critical variable for growth. In scientific argumentation, students must focus on what varies between experimental conditions, not what stays constant. To help students construct and evaluate arguments: Teach how controlled experiments work—when only one variable changes (presence/absence of CO₂) and the outcome changes (growth/no growth), that variable is critical. Practice interpreting experiments: 'What was kept the same? (soil, water, light) What was different? (CO₂) What happened? (growth vs. no growth) What does this tell us? (CO₂ is essential for growth material).' Emphasize that in controlled experiments, we learn from differences, not similarities. The fact that both had soil tells us nothing; the fact that only the one with CO₂ grew tells us CO₂ provides essential materials.