Reproductive advantages depend on conditions
| English | 中文 | Pinyin |
|---|---|---|
| asexual reproduction/eɪˈsekʃuːəl rɪprəˈdʌkʃn/ | 无性生殖 | wú xìng shēng zhí |
| runner/ˈrʌnə/ | 匍匐茎 | pú fú jīng |
What would explain this observation?
- A nursery wants many plants with one successful characteristic, while a changing habitat rewards variation. The useful reproductive route depends on the question being asked.
- Start with a prediction. State the quantities or features you would compare, then decide what evidence could distinguish two explanations.
Build the model
- Sexual reproduction produces variation. If the environment changes, some offspring may have inherited characteristics giving a survival advantage through natural selection. Humans can select parents and offspring with useful characteristics over generations. Finding mates and forming gametes can cost time and energy.
- asexual reproduction 无性生殖: Reproduction without fusion of gametes; runner 匍匐茎: A plant stem that can form new plants asexually.
Which is an advantage of sexual reproduction when conditions change?
Asexual reproduction needs only one parent, avoids finding a mate and can produce many identical offspring quickly when conditions are favourable. Shared inherited susceptibility can become a disadvantage if conditions change. Malaria parasites reproduce asexually in the human host and sexually in the mosquito. Many fungi use asexual spores but also sexual reproduction. Strawberries can form runners and seeds; daffodils can divide bulbs as well as form seeds.
Match each technical term to its precise meaning.
Use the definitions to distinguish related quantities and processes.
Choose evidence that can test it
- Asexual reproduction needs only one parent, avoids finding a mate and can produce many identical offspring quickly when conditions are favourable. Shared inherited susceptibility can become a disadvantage if conditions change. Malaria parasites reproduce asexually in the human host and sexually in the mosquito. Many fungi use asexual spores but also sexual reproduction. Strawberries can form runners and seeds; daffodils can divide bulbs as well as form seeds.
- Compare supplied life-cycle and environmental evidence using benefit → condition → limitation. For an unfamiliar organism, use the described reproduction rather than guessing its biology. School observations of runners or bulb division can illustrate asexual routes; do not culture pathogens or use infected material.
Which two habits make the investigation or model in this case more defensible?
Compare supplied life-cycle and environmental evidence using benefit → condition → limitation. For an unfamiliar organism, use the described reproduction rather than guessing its biology. School observations of runners or bulb division can illustrate asexual routes; do not culture pathogens or use infected material.
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 supplied model starts with 5 clones and each produces 3 surviving new plants during one interval. New plants = 15; with the original 5 retained, total = 20. This differs from replacing each parent with three offspring. State which count the question requests before calculating a growth advantage.
Seven retained parent plants each produce two surviving new plants. Find total plants after the interval. Use the same sequence: known quantities → model → relation → substitution → unit and interpretation.
Seven retained parent plants each produce two surviving new plants. Find total plants after the interval.
The result is 21 plants. Known: a supplied model starts with 5 clones and each produces 3 surviving new plants during one interval. New plants = 15; with the original 5 retained, total = 20. This differs from replacing each parent with three offspring. State which count the question requests before calculating a growth advantage.
Check the conclusion and its limits
- Asexual reproduction is not always superior and sexual variation does not guarantee survival. A fungus producing spores is not necessarily using only one reproductive route. Natural selection acts on existing variation rather than organisms choosing a useful change.
- Return to the original observation. Explain what the result supports, which conditions it assumes, and one way to test a competing explanation.
Variation guarantees every offspring survives environmental change. This claim is false: Asexual reproduction is not always superior and sexual variation does not guarantee survival. A fungus producing spores is not necessarily using only one reproductive route. Natural selection acts on existing variation rather than organisms choosing a useful change.
Reproductive advantages depend on conditions: Asexual reproduction needs only one parent, avoids finding a mate and can produce many identical offspring quickly when conditions are favourable. Shared inherited susceptibility can become a disadvantage if conditions change. Malaria parasites reproduce asexually in the human host and sexually in the mosquito. Many fungi use asexual spores but also sexual reproduction. Strawberries can form runners and seeds; daffodils can divide bulbs as well as form seeds.
Variation guarantees every offspring survives environmental change.
Asexual reproduction is not always superior and sexual variation does not guarantee survival. A fungus producing spores is not necessarily using only one reproductive route. Natural selection acts on existing variation rather than organisms choosing a useful change.
Reproduction without fusion of gametes: write the technical term.
asexual reproduction means Reproduction without fusion of gametes.