AC9S6U01: Investigate the physical conditions of a habitat and analyse how the growth and survival of living things is affected by changing physical conditions

Learning intention: Measure a physical habitat condition, analyse organism responses and make a qualified evidence-based claim.

Curriculum focus: Investigate the physical conditions of a habitat and analyse how the growth and survival of living things is affected by changing physical conditions.

Success criteria

• distinguish physical conditions from living factors
• design a controlled comparison with a measurable response
• use tables and observations to explain growth or survival without overstating causation

physical condition

a non-living measurable feature such as light, water, temperature, salinity or oxygen

biotic factor

a living influence such as food, predators or competitors

changed variable

the condition deliberately altered

measured variable

the response recorded

controlled variable

a factor kept the same for a fair comparison

qualified conclusion

a claim limited to what the evidence supports

1. Name the physical condition and organism response.
2. Change one condition while holding relevant factors constant.
3. Measure several organisms or repeat observations.
4. Compare results using a table or graph.
5. State the pattern and acknowledge limitations.

Physical and living factors

Physical conditions include light, temperature, moisture, salinity, oxygen, soil and shelter. Food, predators and competitors are living factors; both can influence survival, but this code focuses on measured physical conditions.

Investigation model

Use comparable organisms, deliberately vary one physical condition, keep other relevant factors stable, measure growth, activity, distribution or survival, and repeat. Ethical fieldwork minimises disturbance.

Analyse rather than guess

Describe the measured pattern first. Then explain how the changed condition may affect the organism. A correlation supports a cautious relationship claim but does not prove one cause when other factors changed.

Boundary and misconceptions

Not every environmental change is harmful, and no organism survives anywhere merely because food is present. Optimum conditions can lie between extremes. One site or one organism is not enough for a universal claim.

• Is shade a physical condition? Shade describes reduced light, a physical condition; shelter may also alter temperature and moisture.
• Does a pattern prove causation? Only a well-controlled repeated investigation supports a causal claim; a field survey usually supports association.
• Why repeat? Repeats reveal variation and make a mean or consistent pattern more dependable.

• Mangrove seedlings in 0, 10 and 30 parts-per-thousand salt water grow means of 12, 9 and 3 new leaves. Which claim is supported? Hint: Limit the claim to the species, conditions and outcome measured.
• Shade plots were also watered twice as often as sunny plots, and shaded plants grew taller. What can the study conclude? Hint: Find every factor that differed between groups.
• A reef survey records water temperature, wave exposure, coral cover and fish number. Which pair contains only physical conditions? Hint: Separate non-living conditions from organisms.
• More seedlings occur beside a creek than on a ridge. Which next measurement is most relevant to a physical-condition explanation? Hint: Measure the condition named in the explanation at both sites.
• Algae growth is low at 5°C, high at 20°C and low at 40°C. Which interpretation is best? Hint: Compare all three results, including both extremes.
• A student counts insects under one log and reports on the whole forest. What improvement matters most? Hint: Match sampling scale to conclusion scale.

• Support: highlight the changed feature, observation and comparison before writing a claim.
• Core: solve an unseen context and justify the answer with precise evidence.
• Extend: evaluate a limitation, competing explanation or misleading model while staying within Year 6 science.

Given two habitat sites, name one physical condition to measure, one organism response, one control and one limitation.

Evidence of mastery: The student links a measured physical condition to growth or survival using qualified evidence and identifies when another changed factor prevents a single-cause claim.