Biotic factors: changing living relationships
| English | Français |
|---|---|
| biotic factor/baɪˈɒtɪk ˈfæktə/ | facteur biotique |
| pathogen/ˈpæθədʒn/ | pathogène |
What would explain this observation?
- A plant’s decline after a competing species arrives could reflect competition, but matching dates alone do not rule out drought or disease.
- Start with a prediction. State the quantities or features you would compare, then decide what evidence could distinguish two explanations.
Build the model
- Biotic factors 生物因素 arise from living organisms and their interactions. Food availability affects survival and breeding. New predators may reduce prey, pathogens 病原体 can cause disease, and competitors can reduce access to resources. If a population becomes too small or dispersed, individuals may have difficulty finding mates and successful breeding can fall.
- biotic factor: A living organism or interaction affecting a community; pathogen: An organism or agent causing disease.
Which is a biotic change?
The effect can spread through interdependent populations. Fewer prey may later reduce predator numbers; less pollination can reduce seed production. Explain the immediate link before proposing indirect changes. Not every new species outcompetes all existing species, and the effect depends on resources and local conditions.
Match each technical term to its precise meaning.
Use the definitions to distinguish related quantities and processes.
Choose evidence that can test it
- The effect can spread through interdependent populations. Fewer prey may later reduce predator numbers; less pollination can reduce seed production. Explain the immediate link before proposing indirect changes. Not every new species outcompetes all existing species, and the effect depends on resources and local conditions.
- Use supplied before/after data with sampling effort and abiotic conditions stated. Identify alternative explanations and suggest useful comparison locations or repeated observations. Do not introduce organisms or pathogens into habitats to test an explanation; classroom work uses existing safe observations and prepared evidence.
Which two habits make the investigation or model in this case more defensible?
Use supplied before/after data with sampling effort and abiotic conditions stated. Identify alternative explanations and suggest useful comparison locations or repeated observations. Do not introduce organisms or pathogens into habitats to test an explanation; classroom work uses existing safe observations and prepared evidence.
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 prey count changes from 80 to 60 after a new predator arrives. Decrease = 20/80×100 = 25%. This describes the change, not proof that predation caused every loss. Births, migration, sampling and other pressures may also contribute.
A supplied prey count falls from 120 to 90. Calculate percentage decrease. Use the same sequence: known quantities → model → relation → substitution → unit and interpretation.
A supplied prey count falls from 120 to 90. Calculate percentage decrease.
The result is 25 %. Known: a fictional prey count changes from 80 to 60 after a new predator arrives. Decrease = 20/80×100 = 25%. This describes the change, not proof that predation caused every loss. Births, migration, sampling and other pressures may also contribute.
Check the conclusion and its limits
- A pathogen is biotic; temperature is abiotic. Food availability is a living-resource relationship even when a record measures its amount numerically. A fall in a population does not necessarily mean that the species became globally extinct.
- Return to the original observation. Explain what the result supports, which conditions it assumes, and one way to test a competing explanation.
A population decline after a predator arrives proves no other factor contributed. This claim is false: A pathogen is biotic; temperature is abiotic. Food availability is a living-resource relationship even when a record measures its amount numerically. A fall in a population does not necessarily mean that the species became globally extinct.
Biotic factors: changing living relationships: The effect can spread through interdependent populations. Fewer prey may later reduce predator numbers; less pollination can reduce seed production. Explain the immediate link before proposing indirect changes. Not every new species outcompetes all existing species, and the effect depends on resources and local conditions.
A population decline after a predator arrives proves no other factor contributed.
A pathogen is biotic; temperature is abiotic. Food availability is a living-resource relationship even when a record measures its amount numerically. A fall in a population does not necessarily mean that the species became globally extinct.
A living organism or interaction affecting a community: write the technical term.
biotic factor means A living organism or interaction affecting a community.