All practice questions

Archaeologists studying early agriculture often struggle to identify crop cultivation sites because soft plant tissues decay rapidly in humid climates, leaving little organic material behind. To overcome this limitation, researchers have increasingly relied on the analysis of phytoliths—microscopic silica structures that form inside plant cells and persist in soil for millennia. By extracting these durable microfossils from sediment samples at the Xihuano site in Ecuador, researchers successfully identified distinct structural variations characteristic of domesticated squash. Consequently, this methodology not only confirmed early cultivation at the site but also enabled researchers to construct a more precise timeline of agricultural development in the region.

Which choice best describes the overall structure of the text?

Which word most logically and precisely completes the text?

Although the new software update was expected to revolutionize the company's daily operations, its immediate effects were ______; employees noticed almost no difference in their workflow during the first few weeks.

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

In a study of deep-sea hydrothermal vents in the Mariana Trench, marine biologist Dr. Elena Rostova and her team analyzed the metabolic pathways of the newly discovered chemolithoautotrophic bacterium *Sulfurimonas maris*. The researchers found that unlike related species from shallower vents that rely exclusively on hydrogen oxidation, *Sulfurimonas maris* possesses genes encoding both hydrogenases and enzymes for the oxidation of thiosulfate. However, laboratory assays showed that the bacterium only expresses the thiosulfate oxidation genes when local concentrations of dissolved oxygen drop below a specific threshold of $5\text{ micromoles per liter}$. This genetic adaptation allows *Sulfurimonas maris* to maintain energy production in highly fluctuating oxygen zones near the vent chimney.

Based on the text, what is true of the expression of thiosulfate oxidation genes in *Sulfurimonas maris*?

Botanist Dr. Elena Torres investigated how desert wildflowers adapt to drought conditions to ensure pollination. Torres claimed that when soil moisture levels are low, these wildflowers produce a stronger scent to attract pollinators from further away. Which choice, if true, most directly supports Torres's claim?

For decades, archaeologists assumed that the spread of dairy farming in prehistoric Europe was driven by the rapid natural selection of lactase persistence—the genetic mutation allowing adults to digest milk. However, a recent analysis of lipid residues on ancient pottery shards from the Iberian Peninsula reveals that early agriculturalists were processing dairy products long before the genetic mutation became widespread in the region. By demonstrating that dairy consumption preceded the genetic adaptation, the study suggests that cultural practices of milk processing, such as fermenting milk into cheese or yogurt to lower lactose content, may have acted as a buffer. Consequently, these cultural innovations created the evolutionary pressure that eventually favored the lactase persistence gene, rather than the gene facilitating the practice.

Which choice best states the main purpose of the text?

In the eighteenth century, marine navigation faced a major obstacle: sailors could not accurately determine their longitude at sea, leading to costly and dangerous shipwrecks. The British Parliament offered a massive financial reward to anyone who could solve this issue. While astronomers argued that mapping the moon and stars was the only viable path, self-taught clockmaker John Harrison proposed a mechanical solution. Harrison designed and built the H4, a highly precise marine chronometer that could maintain accurate time despite the motion of a ship and changes in temperature. Ultimately, Harrison’s invention revolutionized navigation, proving that mechanical timekeeping was superior to astronomical observations for determining location at sea.

Which choice best states the main purpose of the text?

Moon jellyfish (*Aurelia aurita*) thrive in warmer ocean waters, which speed up their reproduction. However, warmer water also contains less dissolved oxygen, which jellyfish need to survive. While modest temperature increases cause jellyfish populations to grow, extreme temperature increases deplete oxygen to levels that limit jellyfish survival. Thus, in areas experiencing extreme ocean warming, moon jellyfish populations will likely

Which choice most logically completes the text?

The resurrection plant (*Selaginella lepidophylla*) is a desert dweller renowned for its ability to survive extreme dehydration. During prolonged dry spells, the plant curls its stems into a tight, brown ball, entering a dormant state that minimizes water loss. When exposed to moisture, the stems uncurl and regain their green color, a process that can occur in as little as three hours. However, this rehydration is purely mechanical; the plant does not resume active growth until its root system is fully re-established in moist soil.

Based on the text, what is true of the resurrection plant during dry spells?

Marine biologist Dr. Teresa Rossi and colleagues investigated the acoustic behavior of humpback whales (*Megaptera novaeangliae*) during foraging. The team hypothesized that humpback whales modify the acoustic structure of their "feeding calls" to coordinate cooperative bubble-net feeding only when the local density of their prey (krill) falls below a specific threshold. According to the researchers, this acoustic modification serves to recruit conspecifics and organize group foraging to optimize efficiency under scarce resource conditions, whereas in areas of high prey density, whales forage individually without using these modified calls.

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

While many scholars have historically characterized the transition to agriculture as a deliberate choice driven by the desire for long-term food security, recent archaeological evidence from the Fertile Crescent suggests that the process was far more ______; rather than following a singular, forward-looking strategic plan, early cultivation occurred in fits and starts over several millennia, heavily influenced by unpredictable local climate fluctuations.

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

Which word completes the text with the most logical and precise meaning?

In archaeological science, stable isotope analysis of nitrogen ($^{15}\text{N}$) in bone collagen has long been used to reconstruct the dietary profiles of ancient populations, with elevated values typically associated with high consumption of animal or marine proteins. However, recent studies by biochemist Elena Moreno and colleagues demonstrate that environmental factors, such as prolonged soil aridity and specific agricultural fertilization practices, can artificially elevate bone nitrogen levels in herbivores, thereby mimicking a high-meat diet in the consumer record. Consequently, researchers must now cross-reference isotopic data with archaeobotanical evidence of local water availability before drawing conclusions about ancestral foodways. This methodological refinement suggests that previous estimates of meat consumption in early agricultural societies may have been significantly overestimated.

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

In 1967, astronomer Jocelyn Bell Burnell detected a series of highly regular radio pulses while analyzing data from a newly constructed radio telescope. Initially, some researchers speculated that these rapid, precise signals might be transmissions from extraterrestrial civilizations, jokingly referencing the source as 'LGM-1' (Little Green Men). However, Burnell and her advisor, Antony Hewish, soon identified several other sources emitting similar periodic signals from vastly different regions of the sky. This discovery of multiple, dispersed sources rendered the artificial transmission hypothesis highly improbable, as it would require multiple civilizations to broadcast identical signals simultaneously. Consequently, the scientific community accepted that these pulses originated from a natural, previously unobserved astronomical phenomenon, later identified as rapidly rotating neutron stars, or pulsars.

Which choice best states the main purpose of the text?

In the early twentieth century, the introduction of the assembly line revolutionized manufacturing by breaking down complex assembly tasks into simple, repetitive steps. Proponents of this system argued that it would drastically reduce production costs and make consumer goods affordable for the general public. However, critics quickly pointed out that the monotony of such repetitive labor led to high worker turnover and diminished job satisfaction, prompting some factories to introduce rotating shifts.

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

For over a century, scholars of political economy debated the compatibility of Adam Smith's *The Theory of Moral Sentiments* (which posits sympathy as the primary driver of human behavior) and *The Wealth of Nations* (which emphasizes self-interest). Nineteenth-century German commentators termed this apparent contradiction 'Das Adam Smith Problem,' arguing that Smith had undergone a fundamental shift in his view of human nature. However, modern scholarship has largely resolved this division by demonstrating that Smith did not view sympathy and self-interest as mutually exclusive forces. Rather, sympathy serves as the underlying social framework that establishes moral bounds, within which self-interested economic exchanges can function productively. Thus, the two works represent complementary parts of a unified, overarching inquiry into the moral and economic foundations of civil society.

Which choice best states the main purpose of the text?

Archaeologist Dr. Sofia Al-Jamil and her team investigated the dietary habits of the ancient Maya during the Terminal Classic period (c. 800–900 CE) at the site of Ucanal. Al-Jamil hypothesized that during periods of prolonged drought, the population shifted their primary crop consumption from maize (*Zea mays*), which is highly drought-sensitive, to more drought-resistant wild tubers and root crops. Which choice, if true, would most directly support the team's hypothesis?

In botany, researchers have examined the role of mycorrhizal networks, which are underground fungal webs that connect plant roots. Dr. Charles Chen demonstrated that these networks allow mature trees to share surplus sugars with younger seedlings. This resource sharing helps seedlings survive in shaded forest understories where sunlight is scarce. Thus, the fungal network acts as a crucial support system that increases the survival rate of the entire forest community.

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

The Martian meteorite Northwest Africa (NWA) 7034, nicknamed "Black Beauty," contains significantly more water than most other Martian meteorites. In a study, planetary scientist Dr. Ananya Sen and her team analyzed the meteorite's clasts, which are fragments of older rocks cemented together. The researchers determined that the water is primarily locked within apatite crystals inside the basaltic clasts, rather than in the surrounding impact-melt matrix or as a result of terrestrial contamination. Furthermore, the team found that the isotopic signature of the hydrogen in this mineral-bound water matches the Martian atmospheric composition from approximately 4.4 billion years ago, rather than the contemporary Martian atmosphere or terrestrial reservoirs.

Based on the text, what is true of the water found in the Northwest Africa (NWA) 7034 meteorite?

To defend against herbivorous insects, certain tobacco plants produce nicotine, a potent neurotoxin. However, synthesizing nicotine is metabolically costly, requiring nitrogen that would otherwise support leaf growth. Researchers observed that when tobacco plants are exposed to volatile organic compounds (VOCs) released by neighboring plants already under attack, they do not immediately increase nicotine production. Instead, their roots initiate transcription of genes associated with nicotine synthesis, leaving the actual production pathway inactive until direct herbivore damage occurs. Which choice most logically completes the text?