Natural science passages: reading term-dense texts on biology, chemistry, physics, and earth or space science, following processes and cause-and-effect chains, locating the right detail, and answering from the passage rather than from prior science knowledge.

What this skill is asking

A natural science passage covers biology, chemistry, physics, geology, or astronomy. These passages are term-dense (they introduce specialized vocabulary) and process-driven (they explain how something works, often as a cause-and-effect chain). The crucial fact is that you do not need prior science knowledge: ACT Reading is answered from the passage, which defines the terms it uses and lays out the processes you are asked about. The skill is following a process or causal chain step by step, locating the right detail quickly in dense text, and reading any unfamiliar term as the passage defines it rather than from memory. Students who fear science passages usually fear the wrong thing; the difficulty is dense reading, not science, and the reading techniques that work elsewhere work here.

Answer from the passage, not from science class

The single most freeing fact about science passages is that the text is self-contained.

Following a process or causal chain

Natural science questions often test whether you can follow a chain: warmer water holds less oxygen, so lower oxygen, which stresses the fish. The answer to "what causes the stress?" is found by tracing the chain the passage lays out, not by supplying a plausible cause (pollution, fishing) from outside. This reuses the cause-and-effect discipline: accept the link the text states, and reject causes the passage never mentions. For an unfamiliar term, find the passage's definition (usually nearby) and read the term as defined; the test is whether you can use the passage's own language, not whether you knew the word.

A worked science question

Why natural science is reading, not science

Natural science is the passage type students most often dread and least need to, because it is a dense-reading task, not a science test. It shares the informational toolkit with social science and humanities, gathered in reading informational passages, and it relies heavily on cause and effect for following processes. Read it from the passage, follow the chain, and use the given definitions, and the science passage becomes one of the most answerable on the test, because everything you need is on the page.

Try this

Q1. Do you need prior science knowledge for ACT natural science passages? Explain. [Recall]

• Cue. No. ACT Reading is answered from the passage, which defines its terms and lays out its processes. The difficulty is dense reading, not science, so you use the passage's own definitions and chains, not outside facts.

Q2. A science passage says rising temperatures melt sea ice, which exposes darker water that absorbs more heat. What does the passage give as the effect of melting sea ice? [Short explanation]

• Cue. Exposing darker water that absorbs more heat. You read it by following the causal chain the passage lays out (melting ice exposes darker water, darker water absorbs more heat), answering from the stated chain rather than any outside knowledge of climate science.