All practice questions

In planetary science, the core-accretion model posits that giant planets form by first accumulating a massive solid core, which then rapidly attracts surrounding hydrogen and helium gas. For planets forming far from their host stars, this gas is cold and dense, making it highly susceptible to rapid gravitational collapse onto the core. ________ the gas envelope is captured in a brief geological window rather than over tens of millions of years.

Which choice completes the text with the most logical transition?

Which choice completes the text with the most logical and precise word or phrase?

Text 1
Historians have traditionally maintained that the introduction of the potato to Europe from South America in the sixteenth century was the single most important catalyst for the continent's rapid population growth. Because potatoes yielded far more calories per acre than traditional grains, their cultivation directly reduced the frequency of famines. This agricultural shift allowed rural communities to sustain much larger families and ultimately transformed the demographic landscape of Europe.

Text 2
While the potato certainly improved food security in sixteenth-century Europe, recent demographic analyses suggest that its role in the population boom has been exaggerated. Researchers argue that other concurrent factors played equally significant roles. For instance, a gradual warming trend in the regional climate improved overall crop yields, and a decline in plague outbreaks reduced mortality, indicating that Europe's population rise was not driven by a single crop.

Based on the passages, how would the author of Text 2 most likely characterize the claim in Text 1 that the potato was the 'single most important catalyst' for Europe's population growth?

In her study of early marine navigation, historian Clara Vance argues that the development of the marine chronometer by John Harrison did not immediately revolutionize seafaring as is commonly assumed. Instead, she highlights that the adoption of the device was hindered by the high cost of production and the skepticism of the British Board of Longitude, which favored astronomical methods. To demonstrate this resistance, Vance details a series of letters from the Astronomer Royal Nevil Maskelyne, who repeatedly questioned the reliability of Harrison's H4 timekeeper during sea trials in the 1760s. Consequently, most captains continued to rely on lunar distance calculations for several decades, using the chronometer only as a supplementary tool rather than a primary method of navigation.

Which choice best describes the function of the underlined sentence in the text as a whole?

Phytoplankton produce dimethylsulfoniopropionate (DMSP), which marine bacteria convert into dimethyl sulfide (DMS), a volatile gas that helps seed clouds and reflect solar radiation. Some marine viruses lysogenize phytoplankton, delaying cell death during nutrient-rich periods but triggering rapid lysis under ultraviolet-B (UVB) stress. A research team hypothesized that increased UVB radiation, which typically damages phytoplankton, might paradoxically accelerate DMS-induced cloud cooling. They found that although UVB stress did induce widespread viral lysis, releasing a massive pulse of DMSP into the water column, it also severely depleted the populations of DMS-converting bacteria that rely on living host exudates. Which choice most logically completes the text?

Andean agriculturalists constructed stone-walled terraces called andenes to maximize arable land on steep mountain slopes. Historically, researchers viewed these structures primarily as a straightforward response to topographic constraints. However, recent archaeological and soil analyses suggest that these terraces served a far more sophisticated ecological function. By retaining thermal energy during cold nights and slowly filtering runoff water during heavy seasonal rains, the andenes created stable, localized microclimates. Consequently, scholars now argue that the terrace system was not merely a passive adaptation to mountainous terrain, but a proactive engineering strategy that actively minimized frost risk and prevented soil erosion.

Which choice best describes the overall structure of the text?

Which transition word or phrase best shows the causal link between the sun's solar winds and the composition of the inner planets?

In evolutionary biology, the phenotypic resemblance between two unrelated species inhabiting similar environments is often attributed to convergent evolution. However, researchers have cautioned that such similarity can sometimes be ______ rather than adaptive; features may appear identical not because they provide a shared survival advantage, but as a byproduct of shared structural constraints in the organisms' developmental pathways.

Which choice completes the text with the most logical and precise word or phrase?

Based on the rules of Standard English conventions, which punctuation mark should be placed in the blank to grammatically connect the clauses?

In the cold interstellar medium, gaseous carbon monoxide readily condenses onto cosmic dust grains, forming thick icy mantles. These icy layers act as cosmic catalysts, allowing hydrogen atoms to tunnel through activation barriers and react with the trapped carbon monoxide molecules. Complex organic molecules like methanol, __________, are synthesized in environments far too cold for traditional gas-phase chemistry to occur.

Which choice completes the text with the most logical transition?

Text 1
Behavioral economists have long maintained that loss aversion—the tendency to prefer avoiding losses to acquiring equivalent gains—is a fundamental feature of human decision-making. Pioneered by Daniel Kahneman and Amos Tversky, prospect theory suggests that this asymmetry is hardwired, reflecting an evolutionary adaptation where potential threats are weighted more heavily than opportunities. According to this model, the pain of losing a specific sum of money is psychologically twice as intense as the pleasure of gaining it, resulting in a persistent bias toward risk-averse behavior across diverse economic contexts.

Text 2
While loss aversion is accepted as an empirical fact, researchers like David Gal argue that its psychological basis is misunderstood. Gal contends that people do not possess an inherent cognitive bias against losses; rather, the phenomenon arises from situational factors, particularly attentional inertia. In experiments where participants were prompted to actively consider the potential benefits of risky choices, the apparent aversion to loss vanished. This suggests that decision-makers are not inherently biased toward loss avoidance but are simply more likely to focus on losses unless cognitive interventions guide their attention elsewhere.

Based on the passages, how would the author of Text 2 most likely respond to the claim in Text 1 that loss aversion reflects a 'hardwired' evolutionary adaptation?

For over a century, neuroscientists concentrated almost exclusively on neurons as the sole pathways of information transmission in the brain, relegating glial cells to a purely supportive, structural role. Often described as the 'glue' holding neural networks together, glia were assumed to be inactive in cognitive processes. However, recent research has overturned this view by demonstrating that astrocytes, a type of glial cell, actively modulate synaptic transmission and play a crucial role in synaptic plasticity. By releasing chemical transmitters called gliotransmitters, these cells communicate with neurons and influence learning and memory. Consequently, neurobiology is shifting toward a model where glial cells are recognized as active partners in neural communication rather than passive scaffolding.

Which choice best states the main idea of the text?

Linguist Edward Sapir argued that language is not a static system but a dynamic, ever-changing medium shaped by the social needs of its speakers. While early lexicographers often attempted to document languages in a rigid, unchanging state, Sapir recognized that linguistic forms are inherently ______; they adapt fluidly as communities interact and new cultural concepts emerge.

Which choice completes the text with the most logical and precise word or phrase?

The following passage describes a phenomenon in behavioral economics. Which transition word or phrase most logically completes the blank?

Text 1
Young octopuses of the species *Octopus vulgaris* are frequently observed interacting with inanimate objects, such as shells or pebbles, in what appears to be play. Some marine biologists argue that this play behavior is crucial for cognitive development. By manipulating various shapes and textures, young octopuses are thought to build the complex neural pathways needed to navigate their environments and solve problems as adults. From this view, play is a vital learning phase that prepares the animals for the challenges of survival.

Text 2
In a study of *Octopus vulgaris*, researcher Dr. Kenji Sato monitored juvenile play behavior and subsequent adult problem-solving skills, such as opening jars. Sato's team found no statistical correlation between the frequency of early play and adult success in foraging or puzzle-solving. Instead, Sato suggests that play in octopuses is simply a byproduct of excess energy rather than an essential developmental tool. While play may occur, it does not seem to play a functional role in honing the animals' cognitive abilities.

Based on the texts, how would Dr. Kenji Sato (Text 2) most likely respond to the claim in Text 1 that play is a vital learning phase for young octopuses?

Text 1
Many marine biologists have historically claimed that deep-sea hydrothermal vent ecosystems operate in complete isolation from solar energy. Because these complex animal communities thrive in the absolute darkness of the ocean's abyssal zone where sunlight cannot penetrate, they rely on chemosynthetic bacteria that synthesize energy from geothermal chemicals, representing a food web entirely separate from the sun's influence.

Text 2
It is true that hydrothermal vent bacteria utilize hydrogen sulfide from geothermal activity to produce organic matter. However, the metabolic processes of the complex animals that consume these bacteria require dissolved oxygen. Since this ocean oxygen is ultimately produced by photosynthetic organisms in sunlit surface waters and transported downward, these deep-sea ecosystems remain fundamentally dependent on solar energy.

Match each claim or observation about deep-sea ecosystems with the passage or passages that support it.

Text 1
For decades, planetary scientists have maintained that the bulk of Earth’s water was delivered by carbonaceous chondrites during the late accretion phase of planetary formation. Proponents of this model point to the deuterium-to-hydrogen ($D/H$) ratios of these water-rich meteorites, which are virtually identical to the isotopic signature observed in Earth's modern surface oceans, suggesting a post-formation meteoritic origin.

Text 2
Geochemist Wu and colleagues propose that a substantial fraction of Earth's water instead originated from the primordial solar nebula. The team analyzed deep-mantle rock samples, which yield a significantly lower $D/H$ ratio than that of surface reservoirs. Wu argues this low ratio reflects nebular hydrogen directly absorbed by the early magma ocean, meaning modern ocean values represent a hybrid mixture rather than a purely chondritic source.

Based on the passages, is the statement that geochemist Wu and colleagues would characterize the isotopic match described in Text 1 as insufficient evidence to establish that Earth's water was delivered entirely after the planet's initial formation true or false?

Parchment and vellum, made from processed animal skins, served as the primary writing surfaces in medieval Europe. Traditional histories of technology emphasize the durability of these materials, highlighting how they preserved texts for centuries under varying environmental conditions. However, recent biomolecular analyses of manuscript fragments suggest that medieval scriptoriums were highly sensitive to local ecological constraints, particularly livestock availability. By studying the collagen composition of these documents, researchers have demonstrated that periods of parchment scarcity directly correlated with livestock disease outbreaks and seasonal culling cycles, rather than shifts in scribe preferences or economic demand. Thus, parchment production was deeply intertwined with local agrarian cycles.

Which choice best describes the function of the underlined sentence in the text as a whole?

In behavioral economics, "choice overload" describes the psychological paralysis that occurs when consumers are presented with an excessive number of options. This abundance of choices can overwhelm a shopper's cognitive processing capacity. __________, individuals confronted with a vast selection often decide to walk away without making a purchase at all, or they select a product that fails to satisfy their actual needs.

Which choice completes the text with the most logical transition?

Sociologist Dr. Evelyn Diaz investigated the relationship between remote work and local civic engagement. Some theorists argue that working from home naturally fosters stronger ties to one's immediate geographic community. However, Diaz hypothesized that remote workers do not actually participate in local community events or interact with neighbors at higher rates than traditional commuting workers do, because remote workers primarily use their flexible schedules to manage domestic responsibilities rather than to socialize locally.

Which finding, if true, would most directly support Diaz's hypothesis?