Chapter 3 of 423% of exam

Science

The Science module tests your ability to understand and apply scientific concepts and to reason from data. It draws on three content areas: life science, physical science, and earth and space science. Rather than requiring you to memorize countless facts, the test emphasizes scientific practices such as designing investigations, interpreting graphs, and evaluating evidence. This chapter reviews the big ideas in each content area and the reasoning skills that connect them, helping you read passages, analyze data, and draw sound conclusions.

Life Science

Life science studies living organisms, from cells to ecosystems. Key topics include cell structure and function, the flow of energy through food chains, human body systems, heredity, and evolution. Understanding how organisms obtain energy and pass traits to offspring is central. These ideas explain how life is organized and how living things interact with their environments.

Cells are the basic unit of life
All living things are made of cells, which carry out the processes needed for life.
Energy flows through food chains
Producers make food from sunlight, and consumers and decomposers pass energy through the ecosystem.
Traits are inherited through genes
Offspring receive genetic instructions from parents that determine inherited characteristics.
Evolution changes species over time
Populations change across generations through processes such as natural selection.

Physical Science

Physical science covers matter, energy, and their interactions. You should understand physical and chemical properties, changes of state, chemical reactions, and forms of energy. Distinguishing a physical change from a chemical change is a common test point. Concepts of force, motion, and energy conversion also appear in this area.

Distinguish physical and chemical changes
Physical changes alter form without creating new substances, while chemical changes produce new substances.
Understand properties of matter
Physical properties like density can be measured without changing a substance's identity.
Recognize forms of energy
Energy takes forms such as chemical, kinetic, thermal, and light, and can change from one to another.
Apply forces and motion
Forces like gravity and friction affect how objects move or stay at rest.

Earth and Space Science

Earth and space science examines Earth's systems and its place in the universe. Topics include the water cycle, weather and climate, natural resources, and the solar system. Understanding cycles that move matter and energy through Earth's systems is important. This area also addresses how humans affect and depend on the environment.

Trace the water cycle
Water moves through evaporation, condensation, precipitation, and collection in a continuous cycle.
Distinguish weather and climate
Weather is short-term and local, while climate describes long-term patterns over many years.
Classify natural resources
Renewable resources like sunlight are replenished, while fossil fuels can be used up.
Know the solar system
Planets orbit the Sun, and their distance affects temperature and orbital period.

Scientific Practices and Reasoning

Beyond content, the test assesses how you think like a scientist. You must identify variables, understand controls, and judge whether a conclusion follows from the evidence. Repeating experiments and getting consistent results makes findings more reliable. These reasoning skills apply across all three content areas.

Identify variables
The independent variable is what you change, and the dependent variable is what you measure in response.
Use controls
A controlled experiment changes only one variable at a time so results can be attributed to that factor.
Value repetition
Repeating trials and getting similar results makes conclusions more reliable and trustworthy.
Draw evidence-based conclusions
Base conclusions on the data provided rather than on assumptions or opinions.

Interpreting Data and Graphs

Much of the Science module involves reading data from tables, charts, and graphs. You need to identify trends, compare values, and make predictions based on presented information. Careful attention to titles, labels, axes, and units prevents misreading. Turning raw data into meaningful conclusions is a skill used throughout science.

Read every label
Check the title, axis labels, and units before interpreting a graph or table.
Identify trends
Look for patterns such as steady increases or decreases across the data.
Compare data points
Use the values shown to compare quantities and support or reject a claim.
Make predictions
Extend an observed trend cautiously to estimate values beyond the given data.
Test your knowledge
Practice questions on Science
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Last updated: July 2026

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