Selective breeding: repeat selection, retain the risks
| English | 中文 | Pinyin · 拼音 |
|---|---|---|
| selective breeding/sɪˈlektɪv ˈbriːdɪŋ/ | 选择育种 | xuǎn zé yù zhǒng |
| inbreeding/ˈɪnbriːdɪŋ/ | 近亲繁殖 | jìn qīn fán zhí |
What would explain this observation?
- Choosing a high-yielding parent is only the first step. Selective breeding 选择育种 needs offspring selection across generations and attention to unintended effects.
- Start with a prediction. State the quantities or features you would compare, then decide what evidence could distinguish two explanations.
Build the model
- Selective breeding, or artificial selection, means humans breeding plants and animals for chosen inherited characteristics. Select parents with the desired feature from a mixed population, breed them, select offspring showing the feature and breed those. Repeat over many generations. Examples include disease resistance in food crops, greater meat or milk production, a gentle nature in dogs and large or unusual flowers.
- selective breeding: Human selection of parents and offspring for desired inherited features; inbreeding 近亲繁殖: Breeding closely related individuals, which can increase inherited-defect risks.
Which step must follow breeding the selected parents?
Useful and attractive characteristics are not necessarily the same. Repeatedly breeding closely related individuals can cause inbreeding, making some breeds more prone to disease or inherited defects. A narrow breeding population may reduce variation. Evaluate production benefits alongside health, welfare and resilience rather than treating one selected measurement as the whole organism’s value.
Match each technical term to its precise meaning.
Use the definitions to distinguish related quantities and processes.
Choose evidence that can test it
- Useful and attractive characteristics are not necessarily the same. Repeatedly breeding closely related individuals can cause inbreeding, making some breeds more prone to disease or inherited defects. A narrow breeding population may reduce variation. Evaluate production benefits alongside health, welfare and resilience rather than treating one selected measurement as the whole organism’s value.
- Analyse supplied breeding records with yield, disease and parentage stated. Identify the chosen criterion, describe the repeated selection sequence and compare any health costs. A classroom task can use fictional pedigrees and plant data; animal breeding or welfare interventions are not student experiments.
Which two habits make the investigation or model in this case more defensible?
Analyse supplied breeding records with yield, disease and parentage stated. Identify the chosen criterion, describe the repeated selection sequence and compare any health costs. A classroom task can use fictional pedigrees and plant data; animal breeding or welfare interventions are not student experiments.
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 crop’s mean yield rises from 2.4 to 3.0 kg per plant after the stated selection programme. Increase = 0.6 kg; percentage increase = 0.6/2.4×100 = 25%. Without matched conditions or a comparison line, this observation alone cannot attribute all the increase to inherited selection.
A supplied yield rises from 4.0 to 5.0 kg per plant. Calculate percentage increase. Use the same sequence: known quantities → model → relation → substitution → unit and interpretation.
A supplied yield rises from 4.0 to 5.0 kg per plant. Calculate percentage increase.
The result is 25 %. Known: a fictional crop’s mean yield rises from 2.4 to 3.0 kg per plant after the stated selection programme. Increase = 0.6 kg; percentage increase = 0.6/2.4×100 = 25%. Without matched conditions or a comparison line, this observation alone cannot attribute all the increase to inherited selection.
Check the conclusion and its limits
- Selective breeding does not insert a chosen gene directly into a cell. It uses reproduction and selection over generations. Choosing every parent from one family can intensify inherited risks; a greater average yield is not proof that all other traits improved.
- Return to the original observation. Explain what the result supports, which conditions it assumes, and one way to test a competing explanation.
Selective breeding and inserting a gene with a vector are the same process. This claim is false: Selective breeding does not insert a chosen gene directly into a cell. It uses reproduction and selection over generations. Choosing every parent from one family can intensify inherited risks; a greater average yield is not proof that all other traits improved.
Selective breeding: repeat selection, retain the risks: Useful and attractive characteristics are not necessarily the same. Repeatedly breeding closely related individuals can cause inbreeding, making some breeds more prone to disease or inherited defects. A narrow breeding population may reduce variation. Evaluate production benefits alongside health, welfare and resilience rather than treating one selected measurement as the whole organism’s value.
Selective breeding and inserting a gene with a vector are the same process.
Selective breeding does not insert a chosen gene directly into a cell. It uses reproduction and selection over generations. Choosing every parent from one family can intensify inherited risks; a greater average yield is not proof that all other traits improved.
Human selection of parents and offspring for desired inherited features: write the technical term.
selective breeding means Human selection of parents and offspring for desired inherited features.