Science and Nature: Evidence, Scale and Uncertainty
Science and nature questions reward careful reading of evidence and scale. Core concepts: the scientific method (hypothesis, test, replication, peer review), the difference between correlation and causation, sample size and control groups, and uncertainty (a result is a range, not a single certainty). In nature, know the basics of classification (kingdom, phylum, class, order, family, genus, species), food chains and energy transfer (energy is lost at each level, so food chains are short), and the carbon and water cycles.
Traps are usually overstatement and units. A study showing an association does not prove cause; questions often offer a causal claim as the "obvious" answer. Watch scale and units - metres vs kilometres, millions vs billions, Celsius vs Fahrenheit - and timescales (human vs geological). Another trap is single-study certainty: one study is evidence, not consensus, and peer review checks methods, not truth. Be wary of answers using absolute words ("proves", "always", "never") where the evidence supports only "suggests" or "is associated with".
Rule of thumb: if an answer contains "proves" or "always", check whether the evidence could really support that strength of claim. Usually it cannot.
Worked example: A survey finds people who drink more coffee report better mood. The safe conclusion is an association, not that coffee improves mood - people with better mood might simply drink more coffee, or a third factor might drive both. The correct answer names the correlation and flags the need for a controlled trial.
Remember that energy flows one way through an ecosystem while nutrients cycle.