Information and Ideas

Marine biologist Dr. Clara Silva investigated the impact of offshore wind farms on local benthic communities. Silva hypothesized that the artificial structures (the turbine foundations) serve as artificial reefs, attracting specific filter-feeding species like the blue mussel (*Mytilus edulis*) and subsequently increasing the density of their predators, such as the common starfish (*Asterias rubens*), on and immediately adjacent to the structures compared to surrounding sandy seabed areas.

Which choice, if true, would most directly support Silva's hypothesis?

Marine biologist Dr. Clara Vance and her team investigated how ocean acidification affects the shell-building behavior of the marine snail *Anachis avarosa*. The team exposed groups of snails to either current seawater pH levels or lower pH levels simulating projected ocean acidification. While overall calcification rates declined in the low-pH environment, Vance hypothesized that *Anachis avarosa* selectively allocates its limited calcium carbonate resources to preserve the structural integrity of the shell's apex—which shields vital internal organs—at the expense of the outer body whorl. Which finding from the team's study, if true, would most directly support Dr. Vance's hypothesis?

White clover (*Trifolium repens*) produces hydrogen cyanide (HCN) to deter herbivores, but winter freezing can damage cell membranes, releasing HCN and causing self-poisoning. Consequently, clover populations in colder environments typically exhibit lower rates of HCN production. Although urban areas are generally warmer than rural ones due to the urban heat island effect, researchers in a northern city observed that clover in urban parks where snow was regularly cleared had lower rates of HCN production than clover in undisturbed, snow-covered rural fields nearby. Since snow cover provides thermal insulation that buffers soil from freezing air, which choice most logically completes the text?

Many historians have argued that the adoption of currency in medieval Europe was driven primarily by merchant guilds seeking to facilitate long-distance trade. However, historian Dr. Evelyn Vance hypothesizes that local, small-scale transactions among peasant farmers played a far more critical role in the widespread adoption of minted coins. Vance claims that the regular usage of coinage was sustained not by high-value international commerce, but by the necessity of resolving micro-debts accrued through everyday mutual aid and agricultural cooperation within rural villages. Which choice, if true, would most directly support Vance's hypothesis?

Many plants growing in arid environments possess trichomes, which are tiny, hair-like structures on the surfaces of their leaves. While early botanists hypothesized that these structures functioned primarily as a physical barrier against herbivorous insects, subsequent studies have revealed a different principal role. Researchers found that trichomes form a dense boundary layer that reflects solar radiation and reduces air movement across the leaf surface. By lowering leaf temperatures and slowing transpiration, trichomes primarily serve to conserve water, allowing plants to survive prolonged droughts.

Which choice best states the main idea of the text?

Literary scholar Dr. Marcus Thorne argues that early twentieth-century modernist poetry in America, though often characterized as detached from daily life, frequently employed metaphors of industrial machinery to evoke intimate human emotions. Thorne contends that these poets used mechanical processes to represent the internal psychological states of their speakers, thereby bridging the divide between the impersonal modern world and personal experience.

Which choice, if true, would most directly support Thorne's argument?

In a study of remote workplace dynamics, organizational psychologist Dr. Valeria Rossi investigated the impact of 'micro-rewards'—small, digital tokens of recognition—on employee performance. Rossi hypothesized that while these rewards initially increase engagement, their frequent use eventually undermines intrinsic motivation, particularly for complex, creative tasks. However, she proposed that this negative effect is mitigated when the rewards are peer-nominated rather than system-generated, as peer recognition reinforces a sense of social connectedness that sustains motivation. Which choice, if true, would most directly support Rossi's hypothesis?

Elephants are known for their complex social structures and deep family bonds, which require constant communication over long distances. While they make many sounds that are audible to humans, such as trumpets and rumbles, they also utilize infrasound—low-frequency vibrations that travel through the ground and air. These signals, which are below the range of human hearing, can travel for several miles, allowing separated herds to coordinate their movements and avoid potential dangers. By monitoring these vibrations through their sensitive feet and ears, elephants maintain a cohesive network even when they are out of sight.

Which choice best states the main idea of the text?

Companion planting is the agricultural practice of growing different crop species in close proximity to benefit one or both plants. Some researchers hypothesize that planting marigolds (*Tagetes*) alongside tomato plants (*Solanum lycopersicum*) protects the tomatoes from root-knot nematodes—microscopic pests that damage tomato root systems and reduce fruit yields. To test this hypothesis, the researchers compared tomato plants grown in fields with marigolds to tomato plants grown in fields without marigolds.

Which choice, if true, would most directly support the researchers' hypothesis?

Blue jays (*Cyanocitta cristata*) play a crucial role in the expansion of oak forests across North America. During the autumn months, these birds gather thousands of acorns, burying them in various underground caches to secure food for the winter. While blue jays retrieve many of these stored acorns, they inevitably leave a significant portion recovery-free. These forgotten acorns, buried in favorable soil conditions far from the parent trees, frequently germinate and grow into new oak trees. Consequently, the caching behavior of blue jays is essential for the dispersal and regeneration of oak populations.

Which choice best states the main idea of the text?

Cover crops such as crimson clover are frequently utilized to manage soil quality in agricultural ecosystems. Crimson clover has the capacity to fix nitrogen, an essential element for plant growth, into the soil. To evaluate this effect, researchers compared soil plots planted with crimson clover to plots that remained fallow. Their analysis revealed that the plots with clover exhibited significantly higher nitrogen concentrations. Given that the growth of subsequent crops is highly dependent on the availability of soil nitrogen, this outcome suggests that planting crimson clover between cash crop seasons ______

Which choice most logically completes the text?

In many alpine plants, the synthesis of anthocyanin pigments is upregulated in response to intense ultraviolet-B (UV-B) radiation, serving as a photoprotective shield. Biologists hypothesized that this response is purely plastic, triggered solely by direct exposure. However, in a recent study, researchers grew offspring of alpine plant populations under uniform, low-UV-B greenhouse conditions. Offspring whose parents had experienced high wild UV-B exhibited significantly higher baseline anthocyanin levels than did offspring of parents from low-UV-B environments, despite neither offspring group encountering UV-B. Which choice most logically completes the text?

In 1856, chemist William Henry Perkin was attempting to synthesize quinine, a treatment for malaria, in his home laboratory. During his experiments, Perkin oxidized aniline, which resulted in a dark, sticky residue. When he cleaned the flask with alcohol, the residue dissolved to produce a vibrant purple solution. This substance, which he named mauveine, became the world's first commercially successful synthetic dye. Perkin patented the process and established a factory to manufacture the dye, transforming both the textile industry and the field of industrial chemistry.

Based on the text, what is true about William Henry Perkin's discovery of mauveine?

Marine biologist Dr. Elena Rostova and colleagues investigated the resilience of giant kelp (*Macrocystis pyrifera*) to marine heatwaves. Some researchers hypothesize that kelp forests situated near deep-water submarine canyons are more resilient to ocean warming than those along shallow continental shelves because these canyons facilitate the upwelling of cool, nutrient-rich subsurface water, shielding the kelp from warm surface temperatures. Rostova’s team monitored kelp canopy health at several canyon-adjacent and shelf-adjacent sites during a major heatwave.

Which finding from Rostova’s study, if true, would most directly support the researchers' hypothesis?

In 1982, the Tudor warship *Mary Rose* was salvaged from the Solent seabed after four centuries underwater. To prevent the waterlogged wooden hull from collapsing as it dried, conservators sprayed it with polyethylene glycol (PEG), a synthetic polymer. Because PEG molecules can replace the water within the wood’s cellular structure, the polymer effectively supports the cell walls and prevents shrinkage. Once the wood cells were sufficiently infused and stabilized with PEG over several decades, the spraying process was replaced with controlled air-drying to complete the preservation process.

Based on the text, what is true of the polyethylene glycol used on the *Mary Rose*?

In a study of Neolithic settlements in Southern Europe, archaeologist Dr. Angela Vyas investigated the transition from foraging to farming. Vyas hypothesized that this transition was not driven solely by local environmental changes, but was instead facilitated by an active regional network of cultural exchange that spread shared culinary traditions. To support this hypothesis, Vyas's team analyzed organic residues on pottery fragments from several geographically separated settlements dating back to the early agricultural era.

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

Historian Dr. Evelyn Vance and her team investigated trade patterns in ancient Roman Britain by examining the distribution of imported pottery (terra sigillata). Some scholars argue that rural settlements acquired these goods exclusively from larger urban markets. Vance, however, hypothesized that rural communities participated in direct trade with regional merchants, bypassing urban intermediaries entirely.

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

In a study of the alpine wildflower *Silene acaulis*, ecologist Dr. Elena Rostova investigated the relationship between the plant's root exudates and mycorrhizal fungi. Rostova hypothesized that *S. acaulis* alters the chemical composition of its root exudates to recruit specific nitrogen-fixing fungi only when soil nitrogen levels are depleted. Which choice, if true, would most directly support Rostova's hypothesis?

In marine ecosystems, the California sea hare (*Aplysia californica*) defends itself against predators such as spiny lobsters by secreting a sticky, purple ink containing the compound opaline. Marine biologist Dr. Elena Rossi hypothesized that opaline does not function as a physical barrier or a systemic toxin, but rather acts as a chemical disruptor that temporarily disables the predator's chemosensory organs, rendering them unable to locate food. Which finding from Rossi's study, if true, would most directly support her hypothesis?

Ecologist Dr. Keith Sterling and colleagues investigated the relationship between mature Douglas fir trees (*Pseudotsuga menziesii*) and surrounding understory seedlings in a forest ecosystem. Some researchers have proposed that mature trees actively facilitate the growth of conspecific seedlings (seedlings of the same species) over heterospecific seedlings (seedlings of other species) by transferring carbon through shared underground mycorrhizal networks. Which finding, if true, would most directly support the researchers' proposal?