General Science
What to know
General Science is a broad survey compressed into a few dozen questions, so breadth beats depth. Review five clusters. Biology: cell parts, prokaryotes versus eukaryotes, photosynthesis and respiration, DNA and simple inheritance, major body systems. Chemistry: atomic structure, the periodic table, states of matter, mixtures versus compounds, acids and bases. Physics: Newton's three laws, speed versus velocity versus acceleration, forms of energy, work and power. Earth science: rock types, the water cycle, plate tectonics, weather fronts. Astronomy: planet order and why seasons occur.
Traps
- Absolute words. Choices containing always or never are usually wrong because most science statements have exceptions.
- Near-miss vocabulary: mass versus weight, mitosis versus meiosis, a compound versus a mixture, weathering versus erosion.
- Reversed reactions. Photosynthesis consumes carbon dioxide and water and releases oxygen; cellular respiration does the opposite.
- Seasons come from axial tilt, not from distance to the Sun.
Rule of thumb
Density is the calculation to memorize: density = mass ÷ volume. It settles any floating or sinking question without extra theory.
Worked example
A block has a mass of 60 g and a volume of 20 cm³. Density = 60 ÷ 20 = 3 g/cm³. Because that exceeds the 1 g/cm³ of water, the block sinks. If a choice offers 0.33, that is volume ÷ mass, the inverted fraction, and it is a common distractor.