Science
What to know
This domain covers scientific inquiry, life science, physical science, and Earth and space science. Understand the scientific method and variables (independent, dependent, controlled), characteristics of living things, ecosystems and food webs, cells and heredity basics, states of matter, forces and motion, energy transfer, and Earth systems (water cycle, rock cycle, weather, solar system). Candidates should distinguish observations from inferences and know that scientific explanations require evidence.
Traps to watch
- Confusing independent (manipulated) and dependent (measured) variables.
- Mixing observation (directly sensed) with inference (interpretation).
- Reversing energy flow in a food web (energy moves from producers to consumers).
- Confusing mass (amount of matter) with weight (gravity-dependent).
- Assuming a hypothesis is proven rather than supported by evidence.
Rule of thumb
For experiments, ask "what did the scientist change, what did they measure, and what stayed the same?" That identifies independent, dependent, and controlled variables.
Worked example
A student waters three plants with different amounts of water and measures growth. Amount of water is the independent variable; plant growth is the dependent variable; same soil, light, and pot are controlled variables.