Natural Science ACT Reading passages explain a discovery or process in plain language—biology, chemistry, physics, or earth science topics where cause-and-effect chains and experimental logic matter, with zero outside science knowledge required. This is not the Science section; there are no graphs to interpret.
What to track while you read
- The process or phenomenon being explained.
- Steps in order—what happens first, next, last.
- What the evidence shows vs what researchers still debate.
Passage overview: ACT Reading passage types. Do not confuse with ACT Science reading skills.
Question types that dominate natural science
Detail and inference questions often test whether you follow the causal chain correctly. Function questions may ask why a paragraph describes a mechanism. Guides: detail questions, inference questions, function questions.
Common traps
- Using AP biology or chemistry facts not stated in the passage.
- Reversing cause and effect in a multi-step process.
- Treating a hypothesis as a confirmed result.
Pacing strategy
Natural Science is often the last passage—many students save energy here because the structure is linear. If you are behind on time, skip the hardest question and finish the section. Timing guide: finish ACT Reading on time.
How to drill
After each miss, sketch the cause-effect chain from the passage in three bullets. Practice sources: ACT Reading practice tests guide. Improvement plan: improve ACT Reading score.
Start practicing
Start with a free diagnostic, then drill your weak spots with 15-question quizzes and track how you're doing across Reading, English, and Math. Compare plans whenever you're ready to go further.
This article offers general ACT prep guidance. The ACT can change from year to year, including its format, scoring, policies, test dates, and fees, so always confirm the latest details on the official ACT website at act.org before you make decisions. ACT® is a registered trademark of ACT, Inc. thirty-six is not affiliated with, endorsed by, or sponsored by ACT.