The ACT’s list of Natural Science subjects goes literally from A to Z: anatomy, astronomy, biology, botany, chemistry, ecology, geology, medicine, meteorology, microbiology, natural history, physiology, physics, technology, and zoology.
Natural-science passages generally discuss a single scientific issue and its relevance to the larger world. A passage might discuss a new medical procedure and then underscore what the applications might be for people suffering from a particular disease. Compared to the often straightforward vocabulary of other passages, natural-science passages often contain an abundance of technical vocabulary. Simply approach such unfamiliar vocabulary the way you would any word you didn’t know: by drawing contextual clues. A word that is important for understanding a central point is almost never presented without contextual support.
For example, a passage might read: One of the biggest issues facing biologists is the cause of abiogenesis, the emergence of life from non-living matter.
You should be an astute enough a reader by this point to notice that the potentially unfamiliar term, abiogenesis, is defined by the appositive (a noun phrase that modifies or clarifies another noun phrase) that follows.
You should allow your initial read-through of a science passage to orient you to the structure of the passage, in a way that will allow you to quickly locate a specific reference. Still, the author’s tone and claims can be significant, especially at moments that introduce an opinion that challenges conventional wisdom.
NATURAL SCIENCES SAMPLE PASSAGE:
Off the coast of Oregon, more than a mile beneath the surface, a deep-sea coral is slowly dying. That fact alone is hardly surprising. All sea life dies eventually, and much of it in grisly ways. But what ecologists like Susan von Thun, a senior research technician at the Monterey Bay Aquarium, are most distressed about is the particular cause of this coral’s impending death: human pollution. In this case, a disposable plastic bag, the kind handed out by the millions in markets across the country, has, drawn by currents, wrapped itself around the base of the coral.
This discovery is the result of efforts by the Monterey Bay Aquarium Research Institute to explore and map the ocean floor. In the murky sediment, they have discovered a virtual catalog of human life, especially of the last 30 years: batteries, shoes, plastics, rope, bottles, and more. The worst offender is the single-use plastic beverage bottle, that now ubiquitous artifact of contemporary civilization. “It’s astounding,” says cultural historian Arnold Luxx. “Here we live in a society with excellent drinking water, and for some reason, we’ve decided to pay a thousand times more for bottle water, which is less safe, tastes worse, and consumes immense energy unnecessarily.” He might have added that it is taking a toll on ocean life. That fact has been obvious for decades as fish, birds, and sea mammals have been washing up on shore for that long, caught in plastic six-pack rings. It’s not all bad news—though most of it is. Ocean dwellers are nothing if not resourceful, and some of them have colonized some of the pollution. One clever hermit crab now has a soda can rather than a shell for a house. But those few bits of good news are overwhelmed by the virtual flood of pollution that animals ingest or get caught in. By publicizing this fact, von Thun hopes to be able to encourage people to recycle more or at least to dispose of their waste in ways that prevent it from making its way to the ocean.