Evaluating Arguments Practice Test
•15 QuestionsA literary critic argues that a poet’s later work is more politically engaged than the poet’s early work. The critic notes that in the later collection, 14 of 40 poems explicitly mention elections, labor strikes, or war, while in the early collection, 2 of 35 poems do so. The critic concludes that the poet became more politically engaged over time.
Which of the following is the best evaluation of the critic’s reasoning?
A literary critic argues that a poet’s later work is more politically engaged than the poet’s early work. The critic notes that in the later collection, 14 of 40 poems explicitly mention elections, labor strikes, or war, while in the early collection, 2 of 35 poems do so. The critic concludes that the poet became more politically engaged over time.
Which of the following is the best evaluation of the critic’s reasoning?
PASSAGE IV
NATURAL SCIENCE: This passage is adapted from the article Life in the Dark: The Oasis of the Abyss.
Until the late twentieth century, marine biologists operated under a fundamental assumption: all life on Earth ultimately depended on the sun. Photosynthesis was the undisputed engine of the global food web. It was believed that the deep ocean floor, plunged in perpetual darkness, freezing temperatures, and crushing pressure, was a biological desert. Scientists assumed that the few scavengers living in the abyss survived solely on "marine snow"—the slow drift of dead organic matter falling from the sunlit surface miles above.
That paradigm was shattered in 1977. Geologists piloting the deep-sea submersible Alvin were exploring the Galápagos Rift, a mid-ocean ridge in the eastern Pacific. They were searching for hydrothermal vents—underwater hot springs predicted by plate tectonic theory. They found the vents, but they also found something entirely unexpected: a thriving, densely populated ecosystem.
The vents are formed where the Earth’s tectonic plates spread apart. Freezing seawater seeps down through cracks in the ocean crust and is heated by underlying magma chambers to temperatures exceeding 400°C (750°F). Because of the extreme hydrostatic pressure, the water does not boil. Instead, it becomes superheated and highly corrosive, leaching minerals like iron, copper, and zinc from the surrounding rocks. When this buoyant, mineral-rich fluid shoots back up into the freezing ocean water, the dissolved minerals instantly precipitate out, forming massive chimney-like structures known as "black smokers."
The sheer abundance of life around these toxic, boiling geysers was a biological anomaly. There were blind white crabs, pale eel-like fish, and beds of giant clams. Most striking were the giant tube worms, Riftia pachyptila, which grew up to eight feet long in dense, bush-like clusters, waving blood-red plumes in the dark water. Without sunlight, how was this oasis of life sustaining itself? The answer lay in a process entirely separate from photosynthesis: chemosynthesis.
The vent fluids are rich in hydrogen sulfide ($H_2S$), a chemical compound highly toxic to most known terrestrial and shallow-water organisms. However, specialized microorganisms—chemosynthetic bacteria—have evolved to use the chemical energy stored in the bonds of hydrogen sulfide to convert carbon dioxide and water into organic sugars. In this abyssal ecosystem, these bacteria serve the exact same foundational role that plants serve in a sunlit forest.
The giant tube worms are perhaps the most remarkable example of evolutionary adaptation to this environment. Upon dissection, biologists discovered that the adult Riftia tube worm has no mouth, no digestive tract, and no anus. It cannot eat in any traditional sense. Instead, its body contains a massive internal organ called a trophosome, which houses billions of symbiotic chemosynthetic bacteria. The worm’s red plume acts as a gill, absorbing oxygen, carbon dioxide, and hydrogen sulfide from the water and transporting them via its blood to the bacteria. In return, the bacteria synthesize the organic compounds the worm needs to survive and grow at astonishingly rapid rates.
The discovery of hydrothermal vent communities fundamentally expanded our understanding of biology. It proved that life could thrive in the most extreme, hostile environments on the planet, completely divorced from solar energy. Furthermore, the genetic ancientness of these chemosynthetic bacteria has led some evolutionary biologists to propose a radical new theory: that life on Earth may not have begun in a warm, shallow sunlit tide pool, as Charles Darwin once speculated, but rather in the dark, boiling, chemical-rich crucible of a deep-sea vent.
The information in the final paragraph about the 'genetic ancientness' of chemosynthetic bacteria relates to the information in the first paragraph primarily by:
The information in the final paragraph about the 'genetic ancientness' of chemosynthetic bacteria relates to the information in the first paragraph primarily by: