Plants defend themselves in several ways
| English | Français |
|---|---|
| waxy cuticle/ˈwæksi ˈkjuːtɪkl/ | waxy cuticle |
| herbivore/ˈhɜːbɪvɔː/ | herbivore |
What would explain this observation?
- Plants cannot simply run away from a feeding animal. Their barriers, chemicals and mechanical responses reduce damage in different ways.
- Start with a prediction. State the quantities or features you would compare, then decide what evidence could distinguish two explanations.
Build the model
- Physical defences include cellulose cell walls, a tough waxy cuticle 蜡质角质层 on leaves and layers of dead cells around stems as bark. Bark can fall off, removing attached pathogens. These structures form barriers to entry or damage. Chemical defences include antibacterial substances and poisons that deter herbivores 食草动物.
- waxy cuticle: A protective waxy layer on a plant surface; herbivore: An animal that feeds on plants.
Which is a specified chemical defence?
Mechanical adaptations include thorns and hairs that discourage feeding, leaves that droop or curl when touched, and mimicry that can deter animals. Explain the consequence of each feature: a thorn affects contact or feeding, while an antibacterial substance affects bacteria. No single defence protects a plant against every threat.
Match each technical term to its precise meaning.
Use the definitions to distinguish related quantities and processes.
Choose evidence that can test it
- Mechanical adaptations include thorns and hairs that discourage feeding, leaves that droop or curl when touched, and mimicry that can deter animals. Explain the consequence of each feature: a thorn affects contact or feeding, while an antibacterial substance affects bacteria. No single defence protects a plant against every threat.
- Observe teacher-approved plants or supplied images without touching unknown hairs, thorns, sap or berries. Classify each feature as physical, chemical or mechanical in the specification’s grouping, then write a feature → effect → protection explanation. A paper model can compare exposed and protected surfaces without using a real poison or provoking animal feeding.
Which two habits make the investigation or model in this case more defensible?
Observe teacher-approved plants or supplied images without touching unknown hairs, thorns, sap or berries. Classify each feature as physical, chemical or mechanical in the specification’s grouping, then write a feature → effect → protection explanation. A paper model can compare exposed and protected surfaces without using a real poison or provoking animal feeding.
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 protected-leaf model records 6 damaged patches among 50 compared with 15 among 50 in an unprotected model. Damage proportions are 12% and 30%, a difference of 18 percentage points. The comparison supports protection under those rules, not a universal reduction for every plant defence.
A fictional model has 8 damaged patches among 40. Calculate percentage damaged. Use the same sequence: known quantities → model → relation → substitution → unit and interpretation.
A fictional model has 8 damaged patches among 40. Calculate percentage damaged.
The result is 20 %. Known: a fictional protected-leaf model records 6 damaged patches among 50 compared with 15 among 50 in an unprotected model. Damage proportions are 12% and 30%, a difference of 18 percentage points. The comparison supports protection under those rules, not a universal reduction for every plant defence.
Check the conclusion and its limits
- A waxy cuticle is a physical barrier and is not an antibody. Plants do not use the same white-blood-cell mechanisms as animals. A poisonous plant can harm people as well as herbivores, so classroom observation must not involve tasting or extracting its chemicals.
- Return to the original observation. Explain what the result supports, which conditions it assumes, and one way to test a competing explanation.
Plants defend themselves by producing white blood cells. This claim is false: A waxy cuticle is a physical barrier and is not an antibody. Plants do not use the same white-blood-cell mechanisms as animals. A poisonous plant can harm people as well as herbivores, so classroom observation must not involve tasting or extracting its chemicals.
Plants defend themselves in several ways: Mechanical adaptations include thorns and hairs that discourage feeding, leaves that droop or curl when touched, and mimicry that can deter animals. Explain the consequence of each feature: a thorn affects contact or feeding, while an antibacterial substance affects bacteria. No single defence protects a plant against every threat.
Plants defend themselves by producing white blood cells.
A waxy cuticle is a physical barrier and is not an antibody. Plants do not use the same white-blood-cell mechanisms as animals. A poisonous plant can harm people as well as herbivores, so classroom observation must not involve tasting or extracting its chemicals.
A protective waxy layer on a plant surface: write the technical term.
waxy cuticle means A protective waxy layer on a plant surface.