General Science
What this domain tests
General Science combines life science, physical science, and earth/space science at an introductory level. Questions ask you to identify structures and processes, apply the scientific method, interpret simple data, and distinguish correct from nearly correct explanations.
Core rules
- A hypothesis is a testable prediction; a theory is a well-supported explanation, not a guess.
- In experiments, the independent variable is changed, the dependent variable is measured, and controlled variables are held constant.
- Cells are the basic unit of life; plant cells have cell walls and chloroplasts, animal cells do not.
- Matter is conserved in physical and chemical changes; density = mass ÷ volume.
- Energy transfers among forms but is not created or destroyed in ordinary processes.
Worked example
A block has mass 240 g and volume 30 cm³. What is its density, and will it float in water with density 1 g/cm³? Density = 240 ÷ 30 = 8 g/cm³. Because 8 g/cm³ is greater than 1 g/cm³, the block is denser than water and will sink. The reasoning is a direct ratio plus a comparison to the reference density.
Traps
- Confusing mass with weight; mass is amount of matter, weight is gravitational force.
- Calling a hypothesis a theory or a theory a hypothesis.
- Mixing up photosynthesis (carbon dioxide + water → glucose + oxygen) with respiration.
- Forgetting that a control group is used for comparison.
- Reading a graph's axis labels carelessly or ignoring units.