Key Science Skills and Biological Foundations

A comprehensive set of vocabulary flashcards covering key science skills, experimental design, data interpretation, and fundamental biological processes like enzyme function and cellular respiration.

Independent Variable

The variable for which quantities are manipulated (selected or changed) by the experimenter, and assumed to have a direct effect on the dependent variable.

Dependent Variable

The variable the experimenter measures, after selecting the independent variable that is assumed to affect it.

Controlled Variable

Variables held constant in an experiment to ensure changes are occurring solely due to the independent variable.

Research Question

A clear, focused, and arguable central inquiry that drives a student investigation within manageable academic and ethical boundaries.

Aim

A broad statement describing the purpose of an investigation, often structured as: To investigate the effect of (IV) on (DV).

Control Group

The group being tested with no deliberate changes (no IV applied), used to compare against experimental groups.

Negative Control

A group treated in the same way as the experimental group but with the independent variable not applied, such as using water instead of a chemical.

Experimental Group

The groups or samples in an investigation in which the independent variable is manipulated.

Extraneous Variables

Factors that are not kept constant or accounted for in an experiment, such as the age of students or hours of sleep.

Placebo

A substance or treatment that appears real but has no therapeutic effect, used for comparison against a real treatment.

Placebo effect

The psychological or physical response a person experiences after being given a placebo.

Hypothesis

A testable statement about how the independent variable is expected to affect the dependent variable, including the direction of change.

VCAA Scientific Method Summary

Summarized by the acronym ICCDRH.

Case Study

An investigation of a particular activity, behaviour, event, or problem containing a real or hypothetical situation and real-world complexities.

Classification

The arrangement of phenomena, objects, or events into manageable sets.

Identification

The process of recognition of phenomena as belonging to particular sets or possibly being part of a new or unique set.

Controlled Experiment

An experimental investigation of the relationship between an independent and dependent variable while controlling all other variables.

Fieldwork

Planned observation and recording of events and behaviours that have not been manipulated to understand natural relationships and make predictions.

Literature Review

The collation and analysis of secondary data related to other people’s scientific findings or viewpoints to answer a question or prepare for an investigation.

Modelling

The construction of physical, conceptual, or mathematical representations to understand, simulate, or make predictions about a system.

Simulation

A process of using a model to study the behaviour of a real or theoretical system, especially when variables cannot be easily controlled.

Qualitative Data

Non-numerical, descriptive, and subjective data, such as a colour change.

Quantitative Data

Data that is measured and represented numerically, such as time, temperature, or mass.

Primary Data

Original data collected and used directly by the researcher.

Secondary Data

Data that already exists and was collected by someone else.

Raw Data

The data researchers collect as they conduct the experiment before it is processed or transformed.

GLUDST

An acronym for graphing criteria standing for: Graph appropriate, Labelled axis, Units included, Descriptive title, Scale, and Trendline.

Bias

Any systematic error that alters results away from the true and fair outcome, often driven by selection issues or observer expectations.

Validity

Describes an experiment or measurement that investigates what it claims to investigate, ensuring only one independent variable is changed at a time.

Reliability

Describes an experiment that produces the same results when repeated, often ensured by quantitative data collection and multiple trials.

Repeatability

The closeness of agreement between results of successive measurements of the same quantity carried out under identical conditions (same observer, instrument, and location).

Reproducibility

The closeness of agreement between results of measurements of the same quantity carried out under changed conditions (different method, observer, or location).

Replication

The process of repeating an experiment multiple times; the more times it is repeated, the more reliable the results become.

Accuracy

Refers to how close a measured value is to the “true value” of the quantity being measured.

Precision

How closely a set of measurement values agree with each other, showing very little spread about their mean value.

Personal Error

Mistakes or miscalculations, such as misreading a scale or incorrectly labelling test tubes, which should be eliminated by repeating the experiment correctly.

Random Error

Unpredictable errors affecting precision present in all measurements (except counting), reduced by taking repeated measurements and calculating an average.

Systematic Error

Consistent errors affecting accuracy where all readings are shifted in one direction from the true value, often due to faulty calibration.

Uncertainty

Refers to the lack of exact knowledge of the value of the quantity being measured, such as $\pm 0.1\,mL$.

Outliers

Readings that lie a long way from the other results, which should be excluded from average calculations.

Theory

A proven conceptual framework that explains and predicts phenomena, such as cell theory or the theory of evolution.

Model (Scientific)

A physical, visual, or verbal representation based on theories, used to simplify complex theoretical concepts.

Law

A description of an observed aspect of nature based on repeated observations that always applies under the same conditions.

Enzymes

Biological catalysts (proteins) that speed up the rate of chemical reactions by reducing the minimum activation energy required.

Biochemical Pathway

A series of enzyme-catalysed reactions where the product of one reaction becomes the substrate for the next.

Denaturation

The permanent loss of an enzyme's 3D shape due to broken tertiary structure bonds, making the active site non-complementary to its substrate.

Optimum Temperature

The temperature at which enzyme activity reaches its peak and the enzyme works at its fastest rate.

Limiting Factor

Any factor that prevents the rate of reaction from increasing further.

Saturation Point

The point in substrate concentration where all enzyme active sites are occupied, causing the reaction rate to plateau.

Photosynthesis

A biochemical pathway that captures light energy and converts it to chemical energy in the form of glucose ($C_6H_{12}O_6$).

Aerobic Cellular Respiration

A biochemical pathway where glucose is broken down to release usable energy in the form of $ATP$, requiring oxygen ($O_2$).

Lactic Acid Fermentation

The form of anaerobic cellular respiration that occurs in animals, converting glucose to lactic acid.

Alcohol Fermentation

The form of anaerobic cellular respiration that occurs in yeast, converting glucose to ethanol.

Inhibitor

A molecule that binds to an enzyme and prevents it from catalysing a reaction.

Competitive Inhibitor

A molecule that directly blocks substrates by binding to the active site of an enzyme.

Non-competitive Inhibitor

A molecule that binds to the allosteric site of an enzyme, altering its 3D shape and active site.

Allosteric site

A site on an enzyme other than the active site where a non-competitive inhibitor can bind.