SI Units & Measurement

In brief:The International System of Units (SI) ensures scientific measurements are standardised globally so scientists everywhere can communicate data consistently.

Scientific method — Steps of a scientific investigation
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Key Points

1SI Units: an international decimal system defining 7 base units.
2Time = second (s), Length = metre (m), Mass = kilogram (kg), Temperature = Kelvin (K).
3Luminous intensity = candela (cd), Amount of substance = mole (mol), Electric current = Ampere (A).
4Derived units are combinations of base units (e.g. m/s for speed, kg/m³ for density).
5Using standard units prevents miscommunication between scientists in different countries.

Learning Outcomes

0 / 2 complete

Design, plan and conduct investigations; explain how reliability, accuracy, precision, error, fairness, safety, integrity, and the selection of suitable equipment have been considered
Organise and communicate their research and investigative findings in a variety of ways fit for purpose and audience, using relevant scientific terminology and representations

Designing Experiments

In brief:A well-designed experiment isolates the effect of one variable while controlling all others. This ensures valid, reliable results.

Key Points

1A hypothesis must be clear, predictive, and falsifiable - not just a guess.
2Example: 'When native and non-native plants are present, bees will visit native plants more frequently.'
3A fair test changes only the independent variable while keeping all others constant.
4Control group: receives no treatment, used as baseline for comparison.
5Experimental group: receives the treatment being tested.
6Double-blind testing: neither participants nor researchers know who receives treatment vs placebo - reduces bias.
7Example: Testing caffeine and heart rate - IV: caffeine dose, DV: heart rate change, CVs: age, gender, diet.

Learning Outcomes

0 / 3 complete

Recognise questions that are appropriate for scientific investigation
Pose testable hypotheses developed using scientific theories and explanations, and evaluate and compare strategies for investigating hypotheses
Design, plan and conduct investigations; explain how reliability, accuracy, precision, error, fairness, safety, integrity, and the selection of suitable equipment have been considered

Science, Society & Ethics

In brief:Science impacts society through economic development, sustainability and ethical decisions. Scientists must consider the broader implications of their work.

Key Points

1Science drives economic development: agriculture, medicine, vaccines, technology.
2Sustainability: maintaining environmental balance and productivity for future generations.
3Ethics: moral principles guiding scientific research - e.g. animal testing, genetic engineering, data privacy.
4Science and society interact: societal needs influence which research gets funded.
5Form fits function: biological structures evolve specifically to match their function.
6Interdependence: all living things depend on each other and their environment.
7Systems thinking: biological events can be described using simplified systems and models.

Learning Outcomes

0 / 3 complete

Evaluate media-based arguments concerning science and technology
Research and present information on the contribution that scientists make to scientific discovery and invention, and evaluate its impact on society
Explain biological phenomena using appropriate means