PSLE Learner’s Guide · Volume 0891
Find your next learning step
During early germination, water uptake can raise fresh mass while respiration uses stored food, so dry mass may fall before photosynthesis replaces the material.
Series routes: Use the complete PSLE Learner’s Guide volume directory, the original PSLE Learning Guide and the Science learning hub.
This guide uses original Primary 6 practice and does not predict a live question. Consult the SEAB PSLE formats examined in 2026 page for official information.
Open the full chapter index
- 1. Separate fresh mass from dry mass
- 2. Track water uptake
- 3. Track stored food use
- 4. Explain dry-mass loss
- 5. Recognise the turning point
- 6. Do not confuse energy with matter
- 7. Design a fair mass investigation
- 8. Control examination claims
- 9. Worked examples
- 10. Independent practice
- 11. Delayed transfer
- 12. Family guidance and FAQs
CHAPTER 1 OF 12 · Back to contents
1. Separate fresh mass from dry mass
Fresh mass includes water inside the seedling, while dry mass is measured after water is removed. The two measurements can move in different directions and must not be treated as interchangeable.
Build the explanation by naming fresh mass versus dry mass and water uptake during germination. A remembered keyword is not enough: connect the observation to the mechanism and identify what would have to change for the conclusion to change.
Repair the nearest misconception by checking stored food used in respiration and returning to photosynthesis timing controls and gas exchange. State why the tempting alternative is too strong, incomplete or about a different stage.
- Check fresh mass versus dry mass.
- Check water uptake during germination.
- Check stored food used in respiration.
- Check photosynthesis timing controls and gas exchange.
CHAPTER 2 OF 12 · Back to contents
2. Track water uptake
A germinating seed absorbs water, causing tissues to swell and activating processes needed for growth. This added water can increase fresh mass even when the amount of dry material decreases.
Build the explanation by naming fresh mass versus dry mass and water uptake during germination. A remembered keyword is not enough: connect the observation to the mechanism and identify what would have to change for the conclusion to change.
Repair the nearest misconception by checking stored food used in respiration and returning to photosynthesis timing controls and gas exchange. State why the tempting alternative is too strong, incomplete or about a different stage.
CHAPTER 3 OF 12 · Back to contents
3. Track stored food use
Before leaves photosynthesise effectively, the embryo uses stored food from the seed. Respiration releases usable energy for cell division, transport and growth.
Build the explanation by naming fresh mass versus dry mass and water uptake during germination. A remembered keyword is not enough: connect the observation to the mechanism and identify what would have to change for the conclusion to change.
Repair the nearest misconception by checking stored food used in respiration and returning to photosynthesis timing controls and gas exchange. State why the tempting alternative is too strong, incomplete or about a different stage.
CHAPTER 4 OF 12 · Back to contents
4. Explain dry-mass loss
Some carbon-containing stored material is broken down during respiration, and products such as carbon dioxide leave the organism. Therefore the measured dry mass can decrease over time.
Build the explanation by naming fresh mass versus dry mass and water uptake during germination. A remembered keyword is not enough: connect the observation to the mechanism and identify what would have to change for the conclusion to change.
Repair the nearest misconception by checking stored food used in respiration and returning to photosynthesis timing controls and gas exchange. State why the tempting alternative is too strong, incomplete or about a different stage.
CHAPTER 5 OF 12 · Back to contents
5. Recognise the turning point
After green leaves develop and receive suitable light, photosynthesis can manufacture food. If food production exceeds respiratory use and losses, dry mass can begin to increase.
Build the explanation by naming fresh mass versus dry mass and water uptake during germination. A remembered keyword is not enough: connect the observation to the mechanism and identify what would have to change for the conclusion to change.
Repair the nearest misconception by checking stored food used in respiration and returning to photosynthesis timing controls and gas exchange. State why the tempting alternative is too strong, incomplete or about a different stage.
CHAPTER 6 OF 12 · Back to contents
6. Do not confuse energy with matter
Energy released by respiration supports life processes, but energy is not converted into new dry mass. Changes in mass must be explained by matter entering, leaving or being rearranged.
Build the explanation by naming fresh mass versus dry mass and water uptake during germination. A remembered keyword is not enough: connect the observation to the mechanism and identify what would have to change for the conclusion to change.
Repair the nearest misconception by checking stored food used in respiration and returning to photosynthesis timing controls and gas exchange. State why the tempting alternative is too strong, incomplete or about a different stage.
CHAPTER 7 OF 12 · Back to contents
7. Design a fair mass investigation
Use similar seeds, equal starting conditions, defined sampling times and separate matched groups for destructive dry-mass measurements. Control light, temperature, water and seed number.
Build the explanation by naming fresh mass versus dry mass and water uptake during germination. A remembered keyword is not enough: connect the observation to the mechanism and identify what would have to change for the conclusion to change.
Repair the nearest misconception by checking stored food used in respiration and returning to photosynthesis timing controls and gas exchange. State why the tempting alternative is too strong, incomplete or about a different stage.
CHAPTER 8 OF 12 · Back to contents
8. Control examination claims
Name the measurement type, identify the material entering or leaving, connect stored food to respiration and state when photosynthesis could change the trend.
Build the explanation by naming fresh mass versus dry mass and water uptake during germination. A remembered keyword is not enough: connect the observation to the mechanism and identify what would have to change for the conclusion to change.
Repair the nearest misconception by checking stored food used in respiration and returning to photosynthesis timing controls and gas exchange. State why the tempting alternative is too strong, incomplete or about a different stage.
CHAPTER 9 OF 12 · Back to contents
9. Worked examples
Worked case 1: A germinating seed gains fresh mass but loses dry mass. Is this possible?
Controlled answer. Yes. Water uptake raises fresh mass while respiration uses stored food and releases products.
Mechanism. Identify the exact relationship, apply the relevant rule and preserve every stated condition. A surface clue may be compatible with several explanations, so the answer must show what makes this case decisive.
Misconception repair. Do not turn partial evidence into complete proof. Name the closest wrong answer, identify its missing condition and explain why the observed evidence supports the narrower conclusion.
Transfer. Explain both measurements separately. Solve the altered case from the mechanism rather than copying the previous wording.
Reverse construction. Begin with the controlled answer “Yes” and invent a fresh prompt that would justify it for the same reason. Then change one decisive condition to create a near-nonexample. This reverse task checks whether the learner owns the boundary rather than merely recognising the original sentence.
Explanation standard. A complete explanation names the observation, connects it to the rule and limits the conclusion to what follows. It should remain valid if decorative details are removed. If the explanation depends on the story topic instead of the decisive relation, rebuild it.
Audit. Recheck fresh mass versus dry mass, water uptake during germination, stored food used in respiration, photosynthesis timing controls and gas exchange. Decide whether the evidence proves the conclusion or only supports a limited statement.
Worked case 2: What does fresh mass include that dry mass largely excludes?
Controlled answer. Water. Drying removes water before measurement.
Mechanism. Identify the exact relationship, apply the relevant rule and preserve every stated condition. A surface clue may be compatible with several explanations, so the answer must show what makes this case decisive.
Misconception repair. Do not turn partial evidence into complete proof. Name the closest wrong answer, identify its missing condition and explain why the observed evidence supports the narrower conclusion.
Transfer. State why this matters during germination. Solve the altered case from the mechanism rather than copying the previous wording.
Reverse construction. Begin with the controlled answer “Water” and invent a fresh prompt that would justify it for the same reason. Then change one decisive condition to create a near-nonexample. This reverse task checks whether the learner owns the boundary rather than merely recognising the original sentence.
Explanation standard. A complete explanation names the observation, connects it to the rule and limits the conclusion to what follows. It should remain valid if decorative details are removed. If the explanation depends on the story topic instead of the decisive relation, rebuild it.
Audit. Recheck fresh mass versus dry mass, water uptake during germination, stored food used in respiration, photosynthesis timing controls and gas exchange. Decide whether the evidence proves the conclusion or only supports a limited statement.
Worked case 3: Why does a seed need stored food before leaves open?
Controlled answer. It requires material for respiration before it can photosynthesise effectively. Respiration supplies usable energy for growth processes.
Mechanism. Identify the exact relationship, apply the relevant rule and preserve every stated condition. A surface clue may be compatible with several explanations, so the answer must show what makes this case decisive.
Misconception repair. Do not turn partial evidence into complete proof. Name the closest wrong answer, identify its missing condition and explain why the observed evidence supports the narrower conclusion.
Transfer. Name the storage tissue in a familiar seed only if given. Solve the altered case from the mechanism rather than copying the previous wording.
Reverse construction. Begin with the controlled answer “It requires material for respiration before it can photosynthesise effectively” and invent a fresh prompt that would justify it for the same reason. Then change one decisive condition to create a near-nonexample. This reverse task checks whether the learner owns the boundary rather than merely recognising the original sentence.
Explanation standard. A complete explanation names the observation, connects it to the rule and limits the conclusion to what follows. It should remain valid if decorative details are removed. If the explanation depends on the story topic instead of the decisive relation, rebuild it.
Audit. Recheck fresh mass versus dry mass, water uptake during germination, stored food used in respiration, photosynthesis timing controls and gas exchange. Decide whether the evidence proves the conclusion or only supports a limited statement.
Worked case 4: What gas may leave as stored food is respired?
Controlled answer. Carbon dioxide. Carbon atoms from food can leave in carbon dioxide.
Mechanism. Identify the exact relationship, apply the relevant rule and preserve every stated condition. A surface clue may be compatible with several explanations, so the answer must show what makes this case decisive.
Misconception repair. Do not turn partial evidence into complete proof. Name the closest wrong answer, identify its missing condition and explain why the observed evidence supports the narrower conclusion.
Transfer. Keep gas loss separate from water uptake. Solve the altered case from the mechanism rather than copying the previous wording.
Reverse construction. Begin with the controlled answer “Carbon dioxide” and invent a fresh prompt that would justify it for the same reason. Then change one decisive condition to create a near-nonexample. This reverse task checks whether the learner owns the boundary rather than merely recognising the original sentence.
Explanation standard. A complete explanation names the observation, connects it to the rule and limits the conclusion to what follows. It should remain valid if decorative details are removed. If the explanation depends on the story topic instead of the decisive relation, rebuild it.
Audit. Recheck fresh mass versus dry mass, water uptake during germination, stored food used in respiration, photosynthesis timing controls and gas exchange. Decide whether the evidence proves the conclusion or only supports a limited statement.
Worked case 5: Repair: dry mass falls because food turns into energy.
Controlled answer. Stored food is broken down and matter leaves in products such as carbon dioxide, while energy is released during respiration. Matter and energy must not be treated as the same thing.
Mechanism. Identify the exact relationship, apply the relevant rule and preserve every stated condition. A surface clue may be compatible with several explanations, so the answer must show what makes this case decisive.
Misconception repair. Do not turn partial evidence into complete proof. Name the closest wrong answer, identify its missing condition and explain why the observed evidence supports the narrower conclusion.
Transfer. Trace carbon. Solve the altered case from the mechanism rather than copying the previous wording.
Reverse construction. Begin with the controlled answer “Stored food is broken down and matter leaves in products such as carbon dioxide, while energy is released during respiration” and invent a fresh prompt that would justify it for the same reason. Then change one decisive condition to create a near-nonexample. This reverse task checks whether the learner owns the boundary rather than merely recognising the original sentence.
Explanation standard. A complete explanation names the observation, connects it to the rule and limits the conclusion to what follows. It should remain valid if decorative details are removed. If the explanation depends on the story topic instead of the decisive relation, rebuild it.
Audit. Recheck fresh mass versus dry mass, water uptake during germination, stored food used in respiration, photosynthesis timing controls and gas exchange. Decide whether the evidence proves the conclusion or only supports a limited statement.
Worked case 6: Why can fresh mass rise rapidly after water is supplied?
Controlled answer. The seed absorbs water and its tissues swell. The added water contributes to the balance reading.
Mechanism. Identify the exact relationship, apply the relevant rule and preserve every stated condition. A surface clue may be compatible with several explanations, so the answer must show what makes this case decisive.
Misconception repair. Do not turn partial evidence into complete proof. Name the closest wrong answer, identify its missing condition and explain why the observed evidence supports the narrower conclusion.
Transfer. Compare with a dry seed. Solve the altered case from the mechanism rather than copying the previous wording.
Reverse construction. Begin with the controlled answer “The seed absorbs water and its tissues swell” and invent a fresh prompt that would justify it for the same reason. Then change one decisive condition to create a near-nonexample. This reverse task checks whether the learner owns the boundary rather than merely recognising the original sentence.
Explanation standard. A complete explanation names the observation, connects it to the rule and limits the conclusion to what follows. It should remain valid if decorative details are removed. If the explanation depends on the story topic instead of the decisive relation, rebuild it.
Audit. Recheck fresh mass versus dry mass, water uptake during germination, stored food used in respiration, photosynthesis timing controls and gas exchange. Decide whether the evidence proves the conclusion or only supports a limited statement.
Worked case 7: When may dry mass begin to rise?
Controlled answer. When photosynthesis in green leaves makes food faster than it is used and lost. Net gain depends on both production and respiration.
Mechanism. Identify the exact relationship, apply the relevant rule and preserve every stated condition. A surface clue may be compatible with several explanations, so the answer must show what makes this case decisive.
Misconception repair. Do not turn partial evidence into complete proof. Name the closest wrong answer, identify its missing condition and explain why the observed evidence supports the narrower conclusion.
Transfer. State the light requirement cautiously. Solve the altered case from the mechanism rather than copying the previous wording.
Reverse construction. Begin with the controlled answer “When photosynthesis in green leaves makes food faster than it is used and lost” and invent a fresh prompt that would justify it for the same reason. Then change one decisive condition to create a near-nonexample. This reverse task checks whether the learner owns the boundary rather than merely recognising the original sentence.
Explanation standard. A complete explanation names the observation, connects it to the rule and limits the conclusion to what follows. It should remain valid if decorative details are removed. If the explanation depends on the story topic instead of the decisive relation, rebuild it.
Audit. Recheck fresh mass versus dry mass, water uptake during germination, stored food used in respiration, photosynthesis timing controls and gas exchange. Decide whether the evidence proves the conclusion or only supports a limited statement.
Worked case 8: Does exposure to light guarantee immediate dry-mass gain?
Controlled answer. No. Leaves must be developed and conditions suitable, and respiration continues.
Mechanism. Identify the exact relationship, apply the relevant rule and preserve every stated condition. A surface clue may be compatible with several explanations, so the answer must show what makes this case decisive.
Misconception repair. Do not turn partial evidence into complete proof. Name the closest wrong answer, identify its missing condition and explain why the observed evidence supports the narrower conclusion.
Transfer. Name other limiting conditions. Solve the altered case from the mechanism rather than copying the previous wording.
Reverse construction. Begin with the controlled answer “No” and invent a fresh prompt that would justify it for the same reason. Then change one decisive condition to create a near-nonexample. This reverse task checks whether the learner owns the boundary rather than merely recognising the original sentence.
Explanation standard. A complete explanation names the observation, connects it to the rule and limits the conclusion to what follows. It should remain valid if decorative details are removed. If the explanation depends on the story topic instead of the decisive relation, rebuild it.
Audit. Recheck fresh mass versus dry mass, water uptake during germination, stored food used in respiration, photosynthesis timing controls and gas exchange. Decide whether the evidence proves the conclusion or only supports a limited statement.
Worked case 9: Why are matched groups needed for dry-mass measurements?
Controlled answer. Drying and measuring usually destroys the sampled seedlings. The same individual cannot continue growing after destructive sampling.
Mechanism. Identify the exact relationship, apply the relevant rule and preserve every stated condition. A surface clue may be compatible with several explanations, so the answer must show what makes this case decisive.
Misconception repair. Do not turn partial evidence into complete proof. Name the closest wrong answer, identify its missing condition and explain why the observed evidence supports the narrower conclusion.
Transfer. Use equal starting groups. Solve the altered case from the mechanism rather than copying the previous wording.
Reverse construction. Begin with the controlled answer “Drying and measuring usually destroys the sampled seedlings” and invent a fresh prompt that would justify it for the same reason. Then change one decisive condition to create a near-nonexample. This reverse task checks whether the learner owns the boundary rather than merely recognising the original sentence.
Explanation standard. A complete explanation names the observation, connects it to the rule and limits the conclusion to what follows. It should remain valid if decorative details are removed. If the explanation depends on the story topic instead of the decisive relation, rebuild it.
Audit. Recheck fresh mass versus dry mass, water uptake during germination, stored food used in respiration, photosynthesis timing controls and gas exchange. Decide whether the evidence proves the conclusion or only supports a limited statement.
Worked case 10: What should be kept constant when testing light?
Controlled answer. Seed type, number, water, temperature, time and other relevant conditions. Controls isolate the effect of light exposure.
Mechanism. Identify the exact relationship, apply the relevant rule and preserve every stated condition. A surface clue may be compatible with several explanations, so the answer must show what makes this case decisive.
Misconception repair. Do not turn partial evidence into complete proof. Name the closest wrong answer, identify its missing condition and explain why the observed evidence supports the narrower conclusion.
Transfer. State the independent variable. Solve the altered case from the mechanism rather than copying the previous wording.
Reverse construction. Begin with the controlled answer “Seed type, number, water, temperature, time and other relevant conditions” and invent a fresh prompt that would justify it for the same reason. Then change one decisive condition to create a near-nonexample. This reverse task checks whether the learner owns the boundary rather than merely recognising the original sentence.
Explanation standard. A complete explanation names the observation, connects it to the rule and limits the conclusion to what follows. It should remain valid if decorative details are removed. If the explanation depends on the story topic instead of the decisive relation, rebuild it.
Audit. Recheck fresh mass versus dry mass, water uptake during germination, stored food used in respiration, photosynthesis timing controls and gas exchange. Decide whether the evidence proves the conclusion or only supports a limited statement.
Worked case 11: A seedling in darkness keeps losing dry mass. Why?
Controlled answer. It continues respiring stored food without enough photosynthesis to replace it. The stored reserve is finite.
Mechanism. Identify the exact relationship, apply the relevant rule and preserve every stated condition. A surface clue may be compatible with several explanations, so the answer must show what makes this case decisive.
Misconception repair. Do not turn partial evidence into complete proof. Name the closest wrong answer, identify its missing condition and explain why the observed evidence supports the narrower conclusion.
Transfer. Predict the long-term limit. Solve the altered case from the mechanism rather than copying the previous wording.
Reverse construction. Begin with the controlled answer “It continues respiring stored food without enough photosynthesis to replace it” and invent a fresh prompt that would justify it for the same reason. Then change one decisive condition to create a near-nonexample. This reverse task checks whether the learner owns the boundary rather than merely recognising the original sentence.
Explanation standard. A complete explanation names the observation, connects it to the rule and limits the conclusion to what follows. It should remain valid if decorative details are removed. If the explanation depends on the story topic instead of the decisive relation, rebuild it.
Audit. Recheck fresh mass versus dry mass, water uptake during germination, stored food used in respiration, photosynthesis timing controls and gas exchange. Decide whether the evidence proves the conclusion or only supports a limited statement.
Worked case 12: Does dry-mass loss mean the seedling is not growing?
Controlled answer. No. Structures can grow using rearranged stored material even while total dry mass falls
Mechanism. Identify the exact relationship, apply the relevant rule and preserve every stated condition. A surface clue may be compatible with several explanations, so the answer must show what makes this case decisive.
Misconception repair. Do not turn partial evidence into complete proof. Name the closest wrong answer, identify its missing condition and explain why the observed evidence supports the narrower conclusion.
Transfer. Growth in size and total dry mass are different measures. Solve the altered case from the mechanism rather than copying the previous wording.
Reverse construction. Begin with the controlled answer “No” and invent a fresh prompt that would justify it for the same reason. Then change one decisive condition to create a near-nonexample. This reverse task checks whether the learner owns the boundary rather than merely recognising the original sentence.
Explanation standard. A complete explanation names the observation, connects it to the rule and limits the conclusion to what follows. It should remain valid if decorative details are removed. If the explanation depends on the story topic instead of the decisive relation, rebuild it.
Audit. Recheck fresh mass versus dry mass, water uptake during germination, stored food used in respiration, photosynthesis timing controls and gas exchange. Decide whether the evidence proves the conclusion or only supports a limited statement.
CHAPTER 10 OF 12 · Back to contents
10. Independent practice
Practice 1: Why is equal seed number important?
Explained answer. Different numbers produce different total masses. The comparison must start on the same basis.
Delayed transfer. Consider using mean mass per seedling. Cover the answer later and rebuild the chain.
Control question. Which exact condition does the nearest wrong answer miss? State it before checking.
Extension. Change one decisive feature while keeping the story similar. Explain why the conclusion now stays or changes.
Independent proof. Restate the answer without copying its wording. Your version must identify the evidence, the governing relationship and the boundary of the claim. Then write one fact that would be relevant but still insufficient on its own. This separates explanation from repetition.
Delayed comparison. Save this item beside the near-nonexample you created. On the next attempt, compare them before answering and point to the single feature that controls the difference. If more than one feature changed, revise the pair so the comparison stays fair.
Practice 2: What is the independent variable in a time-course study?
Explained answer. Germination time or sampling time. Different matched groups are measured at defined times.
Delayed transfer. Name the dependent variable. Cover the answer later and rebuild the chain.
Control question. Which exact condition does the nearest wrong answer miss? State it before checking.
Extension. Change one decisive feature while keeping the story similar. Explain why the conclusion now stays or changes.
Independent proof. Restate the answer without copying its wording. Your version must identify the evidence, the governing relationship and the boundary of the claim. Then write one fact that would be relevant but still insufficient on its own. This separates explanation from repetition.
Delayed comparison. Save this item beside the near-nonexample you created. On the next attempt, compare them before answering and point to the single feature that controls the difference. If more than one feature changed, revise the pair so the comparison stays fair.
Practice 3: What is a useful dependent variable?
Explained answer. Mean dry mass per seedling or total dry mass for equal-sized groups. The choice must be stated and measured consistently.
Delayed transfer. Add units. Cover the answer later and rebuild the chain.
Control question. Which exact condition does the nearest wrong answer miss? State it before checking.
Extension. Change one decisive feature while keeping the story similar. Explain why the conclusion now stays or changes.
Independent proof. Restate the answer without copying its wording. Your version must identify the evidence, the governing relationship and the boundary of the claim. Then write one fact that would be relevant but still insufficient on its own. This separates explanation from repetition.
Delayed comparison. Save this item beside the near-nonexample you created. On the next attempt, compare them before answering and point to the single feature that controls the difference. If more than one feature changed, revise the pair so the comparison stays fair.
Practice 4: Can water uptake alone explain a dry-mass decrease?
Explained answer. No. Water is removed for dry-mass measurement, so matter loss from dry material must be considered.
Delayed transfer. Trace respiratory products. Cover the answer later and rebuild the chain.
Control question. Which exact condition does the nearest wrong answer miss? State it before checking.
Extension. Change one decisive feature while keeping the story similar. Explain why the conclusion now stays or changes.
Independent proof. Restate the answer without copying its wording. Your version must identify the evidence, the governing relationship and the boundary of the claim. Then write one fact that would be relevant but still insufficient on its own. This separates explanation from repetition.
Delayed comparison. Save this item beside the near-nonexample you created. On the next attempt, compare them before answering and point to the single feature that controls the difference. If more than one feature changed, revise the pair so the comparison stays fair.
Practice 5: What is the nearest misconception?
Explained answer. Assuming a larger fresh seedling must have more dry material. Much of the increase may be water.
Delayed transfer. Compare both mass measures. Cover the answer later and rebuild the chain.
Control question. Which exact condition does the nearest wrong answer miss? State it before checking.
Extension. Change one decisive feature while keeping the story similar. Explain why the conclusion now stays or changes.
Independent proof. Restate the answer without copying its wording. Your version must identify the evidence, the governing relationship and the boundary of the claim. Then write one fact that would be relevant but still insufficient on its own. This separates explanation from repetition.
Delayed comparison. Save this item beside the near-nonexample you created. On the next attempt, compare them before answering and point to the single feature that controls the difference. If more than one feature changed, revise the pair so the comparison stays fair.
Practice 6: Why must seedlings be dried to constant mass?
Explained answer. To reduce variation from remaining water. Repeated drying and weighing checks that water removal is complete enough.
Delayed transfer. Describe the stopping criterion. Cover the answer later and rebuild the chain.
Control question. Which exact condition does the nearest wrong answer miss? State it before checking.
Extension. Change one decisive feature while keeping the story similar. Explain why the conclusion now stays or changes.
Independent proof. Restate the answer without copying its wording. Your version must identify the evidence, the governing relationship and the boundary of the claim. Then write one fact that would be relevant but still insufficient on its own. This separates explanation from repetition.
Delayed comparison. Save this item beside the near-nonexample you created. On the next attempt, compare them before answering and point to the single feature that controls the difference. If more than one feature changed, revise the pair so the comparison stays fair.
Practice 7: What evidence would support the photosynthesis turning point?
Explained answer. Developed green leaves, suitable light and a later rise in dry mass compared with controls. Several observations strengthen the interpretation.
Delayed transfer. Avoid claiming cause from timing alone. Cover the answer later and rebuild the chain.
Control question. Which exact condition does the nearest wrong answer miss? State it before checking.
Extension. Change one decisive feature while keeping the story similar. Explain why the conclusion now stays or changes.
Independent proof. Restate the answer without copying its wording. Your version must identify the evidence, the governing relationship and the boundary of the claim. Then write one fact that would be relevant but still insufficient on its own. This separates explanation from repetition.
Delayed comparison. Save this item beside the near-nonexample you created. On the next attempt, compare them before answering and point to the single feature that controls the difference. If more than one feature changed, revise the pair so the comparison stays fair.
Practice 8: State the full method.
Explained answer. Separate fresh and dry mass, track water entering, stored food used in respiration and carbon-containing products leaving, then identify when photosynthesis may produce a net dry-mass gain. Do not convert energy into matter in the explanation.
Delayed transfer. Analyse a new graph. Cover the answer later and rebuild the chain.
Control question. Which exact condition does the nearest wrong answer miss? State it before checking.
Extension. Change one decisive feature while keeping the story similar. Explain why the conclusion now stays or changes.
Independent proof. Restate the answer without copying its wording. Your version must identify the evidence, the governing relationship and the boundary of the claim. Then write one fact that would be relevant but still insufficient on its own. This separates explanation from repetition.
Delayed comparison. Save this item beside the near-nonexample you created. On the next attempt, compare them before answering and point to the single feature that controls the difference. If more than one feature changed, revise the pair so the comparison stays fair.
CHAPTER 11 OF 12 · Back to contents
11. Delayed transfer
On day one, solve clear examples. On day three, mix examples, near-nonexamples and incomplete evidence. On day seven, solve without headings or a word bank. Delay reveals whether the method can be reconstructed independently.
Keep an error log for the first failed stage: reading, representation, rule, execution or checking. The earliest failure identifies the repair.
Interleave this skill with neighbouring ideas that share vocabulary. Classify each item only after naming the distinguishing condition.
In timed work, mark the relationship, apply the rule, write the conclusion and audit one condition. If checking changes the answer, record the overlooked feature.
Create a teach-back card with a near-nonexample on the front and the repaired mechanism on the back. Explain why the tempting answer fails.
Finish with one basic example, one boundary case and one transfer case. Supply explanations that a classmate can verify.
For a second delayed test, reverse the direction: start from a conclusion and invent evidence that would justify it, then evidence that would be insufficient. This exposes the boundary between relevance and proof.
CHAPTER 12 OF 12 · Back to contents
12. Family guidance and FAQs
Guidance for parents and tutors
Ask for the decisive condition before confirming the answer. Use prompts such as “What exactly happened?”, “Which stage or meaning is this?” and “What would prove it?”
Fade support from labelled examples to mixed questions and delayed open response. Independent retrieval after time and topic change is the target.
Praise precise claim control. Narrowing an answer when evidence is incomplete is scientific and academic strength.
Frequently asked questions
Should I memorise the rule?
Memorise the compact rule, then practise examples and near-nonexamples so the conditions remain visible.
What if two answers seem possible?
Return to the exact relationship and choose the option satisfying every stated condition without adding facts.
Why delay practice?
Immediate repetition may depend on the recent explanation; delay tests reconstruction.
How should an error be corrected?
Name the first failed stage and practise it with a changed example.
When is the skill ready?
When the learner can explain, apply and transfer it after a delay.
What is the final audit?
Check relationship, mechanism, claim strength and whole-question fit.
Next routes
Continue at the Science learning hub or return to the series directory.