Higher Tier: germination and fruit ripening signals
| English | 中文 | Pinyin |
|---|---|---|
| gibberellin/ˌdʒɪbəˈrelɪn/ | 赤霉素 | chì méi sù |
| ethene/ˈiːθiːn/ | 乙烯 | yǐ xī |
What would explain this observation?
- Higher Tier: A seed beginning growth and a fruit ripening involve different hormone roles. Correctly naming the signal matters before considering a commercial use.
- Start with a prediction. State the quantities or features you would compare, then decide what evidence could distinguish two explanations.
Build the model
- Gibberellins 赤霉素 are plant hormones important in initiating seed germination. Ethene 乙烯 controls cell division and fruit ripening. These roles are required at Higher Tier, but the mechanisms by which the hormones act are not required. Hormones coordinate responses; they are not the stored food supplying all growth material.
- gibberellin: A plant hormone important in initiating seed germination; ethene: A plant hormone controlling fruit ripening and cell division.
Which role belongs to gibberellins in this course?
Distinguish a hormone effect from the conditions needed for the response. A viable seed still needs suitable environmental conditions. A fruit-ripening comparison needs a matched variety, maturity and observation period. A greater observed response in one treatment does not prove that every species or developmental stage behaves identically.
Match each technical term to its precise meaning.
Use the definitions to distinguish related quantities and processes.
Choose evidence that can test it
- Distinguish a hormone effect from the conditions needed for the response. A viable seed still needs suitable environmental conditions. A fruit-ripening comparison needs a matched variety, maturity and observation period. A greater observed response in one treatment does not prove that every species or developmental stage behaves identically.
- Interpret teacher-provided germination and ripening records with controls. Count germinated seeds using a stated criterion and compare proportions rather than raw counts from unequal groups. School work uses only approved materials; do not release ethene gas or handle concentrated hormone products unsupervised. The task is role/evidence analysis, not molecular-pathway memorization.
Which two habits make the investigation or model in this case more defensible?
Interpret teacher-provided germination and ripening records with controls. Count germinated seeds using a stated criterion and compare proportions rather than raw counts from unequal groups. School work uses only approved materials; do not release ethene gas or handle concentrated hormone products unsupervised. The task is role/evidence analysis, not molecular-pathway memorization.
Work from known quantities
- State the known values and their units. Choose the relation because its assumptions fit this case, then rearrange before substitution.
- Known: a fictional germination trial has 24 germinated seeds among 40 in one stated condition and 15 among 30 in another. Proportions are 60% and 50%, a difference of 10 percentage points. A control and matched conditions are needed before attributing the difference to a hormone.
A fictional condition has 28 germinated seeds among 40. Calculate the percentage. Use the same sequence: known quantities → model → relation → substitution → unit and interpretation.
A fictional condition has 28 germinated seeds among 40. Calculate the percentage.
The result is 70 %. Known: a fictional germination trial has 24 germinated seeds among 40 in one stated condition and 15 among 30 in another. Proportions are 60% and 50%, a difference of 10 percentage points. A control and matched conditions are needed before attributing the difference to a hormone.
Check the conclusion and its limits
- Ethene and ethanol are different substances. Gibberellins are not auxins and need not have the same growth effects. The specification excludes detailed molecular mechanisms here, so a correct GCSE explanation names the role and interprets the supplied evidence.
- Return to the original observation. Explain what the result supports, which conditions it assumes, and one way to test a competing explanation.
Ethene and ethanol are interchangeable names for the same substance. This claim is false: Ethene and ethanol are different substances. Gibberellins are not auxins and need not have the same growth effects. The specification excludes detailed molecular mechanisms here, so a correct GCSE explanation names the role and interprets the supplied evidence.
Higher Tier: germination and fruit ripening signals: Distinguish a hormone effect from the conditions needed for the response. A viable seed still needs suitable environmental conditions. A fruit-ripening comparison needs a matched variety, maturity and observation period. A greater observed response in one treatment does not prove that every species or developmental stage behaves identically.
Ethene and ethanol are interchangeable names for the same substance.
Ethene and ethanol are different substances. Gibberellins are not auxins and need not have the same growth effects. The specification excludes detailed molecular mechanisms here, so a correct GCSE explanation names the role and interprets the supplied evidence.
A plant hormone important in initiating seed germination: write the technical term.
gibberellin means A plant hormone important in initiating seed germination.