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Read the following passage:

Dr. Julian Vance adjusted his spectacles, his breath fogging the glass of the conservatory dome. For decades, he had chased the elusive *Epiphyllum*, convinced its midnight bloom held the key to his late colleague's research. To Julian, the tiny white bud was not merely a plant; it was a testament to a lifetime of quiet dedication, a silent partner in the humid air of the greenhouse. He watched the outer petal tremble, his own heart mimicking its fragile rhythm.

But the conservatory itself cared little for human obsession. Inside the glass walls, hundreds of tropical specimens breathed in unison, their roots drawing nourishment from the rich, damp soil regardless of who watched them. To the casual observer walking the gravel paths outside, the dome was simply a glowing beacon against the dark hills, a warm pocket of life suspended in the chilly autumn night where plants grew and men grew old.

Based on the passage, the narrative point of view shifts from which of the following?

Researchers investigated the effect of light wavelength on the photosynthetic rate of *Elodea* plants. Over a 24-hour period, three identical setups were maintained at a constant temperature of $22^\circ\text{C}$ and exposed to different colors of light (red, blue, or green). The rate of photosynthesis was determined by measuring the volume of oxygen gas produced by the plants in milliliters.

Match each component of the experiment to the correct variable type it represents.

Passage

For billions of years, Mars has transitioned from a warm, wet world with a thick atmosphere to the cold, dry desert we see today. In 2014, NASA’s MAVEN (Mars Atmosphere and Volatile EvolutioN) spacecraft entered orbit to investigate the mechanisms driving this transition. Specifically, researchers hypothesized that the solar wind—a stream of charged particles constantly emitted by the Sun—was responsible for stripping away the Martian atmosphere.

MAVEN's instruments measured the rate of atmospheric ion loss under different solar conditions. During solar storms, such as coronal mass ejections, the rate of ion escape into space increased by a factor of more than ten. Furthermore, MAVEN detected a magnetic 'tail' stretching behind Mars, where solar magnetic field lines drape around the planet and accelerate ions outward. These observations demonstrate that solar activity actively drives the depletion of Mars’s light gases. While some scientists previously argued that internal planetary cooling and the subsequent loss of Mars's global magnetic field were the primary drivers of atmospheric escape, MAVEN's real-time data shows that external solar wind interactions remain the dominant force in the ongoing stripping of the Martian atmosphere.

Question
Match each of the scientific claims on the left with the specific textual evidence on the right that provides direct supporting evidence.

A science class designed four different experiments to study the effects of various independent variables. Match each experimental setup with the correct control group or baseline condition required to validate the results.

Passage A

The transition to a low-carbon economy requires unprecedented quantities of critical minerals like cobalt, nickel, and manganese, which are essential for manufacturing electric vehicle batteries and renewable energy systems. Land-based mining of these resources is increasingly fraught with geopolitical tensions, human rights concerns, and severe local ecological destruction. Fortunately, the abyssal plains of the deep ocean offer an alternative. Vast fields of polymetallic nodules lying thousands of meters below the surface contain rich deposits of these vital metals. While critics raise alarms about the potential disruption to benthic ecosystems, we cannot ignore the carbon-saving imperative of the green transition. The deep sea provides a concentrated, politically stable source of materials that could drastically reduce our reliance on terrestrial fossil fuels. Furthermore, modern marine engineering allows for highly targeted extraction methods that minimize sediment plumes and protect the water column. With robust oversight from international regulatory bodies like the International Seabed Authority, we can establish strict environmental protocols. Responsible deep-sea mining represents a necessary compromise—a calculated trade-off that secures the resources needed to combat global climate change while actively managing localized marine risks.

Passage B

Advocates of deep-sea mining often frame the seabed as a pristine treasury of metals waiting to be harvested for the sake of the planet's climate. However, this utilitarian view ignores the profound ecological risks of introducing heavy industrial machinery to one of Earth's least understood and most fragile environments. Benthic ecosystems, operating in near-freezing temperatures and absolute darkness, host unique species that are highly specialized and extremely slow-growing. The physical disruption caused by mining vehicles scraping the ocean floor will destroy these habitats, creating vast underwater dust storms—sediment plumes—that can drift for miles, choking filter-feeding organisms and disrupting the marine food web. The argument that regulatory frameworks can guarantee 'responsible' mining is wishful thinking; our scientific understanding of deep-sea biodiversity is so rudimentary that we cannot accurately measure, let alone mitigate, the long-term impacts of such disruption. Seeking to solve terrestrial ecological crises by strip-mining the seabed is a dangerous continuation of the same short-sighted exploitation that caused climate change in the first place. We must prioritize recycling, battery innovation, and circular economic models rather than rushing into an ecological frontier where damage is irreversible.

Based on the passages, which of the following statements best describes the primary difference in how the authors of Passage A and Passage B view the potential environmental impact of deep-sea mining?

A plant physiologist formulated the following hypothesis:

*Hypothesis*: Under constant high-light conditions, the rate of transpiration in a particular plant species is determined solely by stomatal conductance. Consequently, any environmental change that reduces stomatal conductance will result in a proportionally identical decrease in the transpiration rate.

To test this hypothesis, the physiologist placed several plants in a controlled chamber under constant high-light conditions. Stomatal conductance and transpiration rate were measured at various relative humidity (RH) levels. Measurements taken at $80\%$ RH served as the baseline ($100\%$). The results are shown in the table below:

Which of the following modifications to the physiologist's hypothesis is most consistent with these results?

An investigator conducted an experiment to evaluate how different concentrations of a newly synthesized chemical compound, Compound Y, affect the rate of starch hydrolysis by the enzyme amylase. The experiment was conducted at $37^\circ\text{C}$ and a neutral pH of $7.0$. Four trials were prepared with the compositions shown in the table below:

The rate of starch hydrolysis was determined for each trial by measuring the concentration of maltose produced after $10\text{ minutes}$.

To determine the effect of Compound Y on amylase activity, the investigator compared the rate of starch hydrolysis in the trials containing Compound Y to the rate in a control group that established the baseline activity of amylase alone. Which trial served as this control group?

The following passage explores the historical development of seventeenth-century London coffeehouses.

In the mid-seventeenth century, London witnessed a social phenomenon that permanently altered its intellectual and political landscape: the rise of the coffeehouse. For a nominal fee of one penny, patrons entered an environment that defied the rigid social hierarchies of early modern England. Scholars, merchants, poets, and politicians sat at common tables, engaging in what historian Jürgen Habermas later termed the 'bourgeois public sphere.' However, the historical development of these spaces was not merely a story of sudden, egalitarian triumph; rather, it progressed through distinct stages of commercial utility, political controversy, and eventual institutionalization.

Initially, coffeehouses served a purely pragmatic function. Merchant ventures and shipping tradesmen utilized the establishments as informal offices to exchange maritime news and conduct transactions. This economic foundation provided the spaces with stability and attracted a diverse clientele. Yet, as the clientele diversified, the nature of the discourse shifted from commercial listings to political debate. This shift marks the second phase of coffeehouse development, wherein these establishments became centers of political unrest. King Charles II, recognizing the threat of unregulated assembly, went so far as to issue a proclamation in 1675 attempting to ban them altogether.

This royal opposition, rather than suppressing the movement, catalyzed its third phase: the emergence of the coffeehouse as a recognized forum for critical public opinion. The public backlash against the King’s ban was so swift and widespread that the proclamation was rescinded within days, a testament to the newfound collective power of the patron class. By successfully surviving this crown challenge, coffeehouses solidified their role as protected, autonomous domains of free expression, paving the way for the structured political parties and independent newspapers of the early eighteenth century.

Ultimately, the evolution of the London coffeehouse reveals a structured progression from commerce to politics. Thus, the coffeehouse was not an overnight anomaly but a gradually evolving institution whose survival depended on its initial economic utility. Its trajectory illustrates how commercial spaces can transform into hubs of intellectual democracy, demonstrating that the layout of our social environments dictates the boundaries of our political discourse.

Which of the following best describes how the author sequences the evidence in the passage to develop the main argument?

A student conducts an experiment to determine how the mass of a toy car affects the distance it travels after rolling down a ramp. The student releases cars of different masses ($50\text{ g}$, $100\text{ g}$, $150\text{ g}$, and $200\text{ g}$) from the same release height on the same ramp and measures the distance each car travels in meters. Which of the following is the independent variable in this experiment?

A student hypothesized that as the temperature of water increases, the maximum mass of sugar that can dissolve in $100\text{ mL}$ of water decreases. To test this, the student measured the maximum mass of sugar dissolved at various temperatures and recorded the results in the table below:

Based on these results, how should the student modify their hypothesis?

Two students discuss the source of heat that warms a deep-sea hydrothermal vent ecosystem.

Student 1
The ecosystem is warmed solely by geothermal energy from Earth's mantle, which heats the seawater as it circulates through subterranean crustal cracks. The sun has no role in warming this environment because solar radiation does not penetrate to these extreme ocean depths.

Student 2
The ecosystem's primary heat source is geothermal energy rising from Earth's mantle. However, minor warming also occurs due to warm, downwelling surface ocean currents that were originally heated by solar radiation.

Based on the descriptions of the two viewpoints, both students agree with which of the following statements?

A planetary satellite orbiting a gas giant exhibits a liquid water ocean beneath a solid ice shell. Three scientists propose different models to explain the source of the thermal energy that prevents the subsurface ocean from freezing.

Scientist 1
The primary source of heat is tidal dissipation. As the satellite follows an eccentric orbit, the gravitational pull of the gas giant causes periodic deformation (flexing) of the satellite's silicate mantle and metallic core. This friction generates tidal heat at a rate of approximately $100\text{ GW}$, keeping the subsurface ocean liquid. Radioactive decay in the core contributes a negligible amount of heat (less than $5\text{ GW}$).

Scientist 2
The satellite's orbit is nearly circular, meaning tidal dissipation contributes less than $2\text{ GW}$ of thermal energy. Instead, the heat is primarily generated by hydrothermal activity at the seafloor. Serpentinization reactions (water reacting with the silicate core) and radioactive decay within the core release heat at a combined rate of $95\text{ GW}$. Hot water plumes carry this energy upward into the subsurface ocean.

Scientist 3
The heat is primarily radiogenic, produced by the decay of radioactive isotopes ($^{40}\text{K}$, $^{232}\text{Th}$, and $^{238}\text{U}$) in the satellite's silicate-rich rocky core, generating a steady heat flux of $80\text{ GW}$. Tidal dissipation is negligible. Furthermore, serpentinization reactions do not occur because the core's silicate minerals have already been fully hydrated.

Based on the descriptions provided, which of the following statements represents a point of agreement among all three scientists?

### Origin of Prebiotic Organics on Early Earth

How organic molecules first accumulated on early Earth to facilitate the origin of life remains a central scientific debate. Three scientists present competing hypotheses regarding the primary source of these prebiotic compounds.

Scientist 1
Prebiotic organic molecules were synthesized in interstellar molecular clouds and delivered to Earth via carbonaceous meteorites and comets during the Late Heavy Bombardment. Early Earth's global atmosphere was dominated by non-reducing gases like $CO_2$ and $N_2$, which prevent the endogenous synthesis of organic compounds. Although heavy impacts caused widespread heating, atmospheric modeling shows that larger meteors and cometary dust particles could enter the atmosphere without reaching pyrolysis temperatures, preserving their organic payloads. Once delivered, these molecules required the presence of liquid water on Earth's surface to accumulate, undergo chemical concentration, and polymerize.

Scientist 2
Prebiotic synthesis occurred endogenously at alkaline hydrothermal vents located on the ocean floor. The global atmospheric composition was irrelevant because these vents provided localized, highly reducing environments rich in $H_2$ and $CH_4$ gases. Chemical reactions were driven by geothermal energy and proton gradients between acidic ocean water and alkaline vent fluids, producing simple organic monomers. Any organic compounds delivered by meteorites would have been completely vaporized and destroyed by the extreme temperatures generated during atmospheric entry and hypervelocity surface impacts. However, the presence of liquid water on Earth's surface was essential to act as the primary solvent that dissolved and transported these synthesized monomers away from the vents, allowing them to accumulate in cooler, stable oceanic reservoirs.

Scientist 3
Prebiotic compounds were synthesized in the upper atmosphere through spark discharges (lightning) acting on localized, reducing gas envelopes. While the global atmosphere was non-reducing, frequent subaerial volcanic eruptions released transient clouds of $CH_4$, $NH_3$, and water vapor. Electrical discharges within these volcanic plumes initiated the synthesis of amino acids and other monomers. Hydrothermal vents could not be the source of prebiotic molecules because their high temperatures (greater than $350^\circ\text{C}$) rapidly decompose organic compounds rather than synthesize them. After atmospheric synthesis, liquid water on Earth's surface was required to wash the organic compounds out of the atmosphere, collecting them in shallow pools where they were shielded from destructive solar ultraviolet radiation and could undergo further prebiotic evolution.

Based on the passages, all three scientists would agree with which of the following statements regarding the conditions required for prebiotic organic molecules to accumulate or evolve on early Earth?

A student performed an experiment to study the reaction between magnesium metal and hydrochloric acid ($HCl$). The student hypothesized that as the concentration of $HCl$ increases, the reaction time will decrease at a constant rate. The student measured the time required for a $1.0\text{ g}$ pellet of magnesium to completely dissolve in $50\text{ mL}$ of $HCl$ at $25^\circ\text{C}$ using different concentrations of the acid. The results are shown in the table below.

Do the results of the experiment support the student's hypothesis?

Origin of Earth's Water

The origin of Earth's water is a subject of ongoing debate among geochemists. Two scientists present their viewpoints on how Earth acquired its oceans.

Scientist 1
Earth's water was delivered primarily by carbonaceous chondrite meteorites during the Late Heavy Bombardment, approximately 3.9 billion years ago. The isotopic ratio of deuterium to hydrogen ($D/H$) in Earth's current oceans ($1.56 \times 10^{-4}$) closely matches the average $D/H$ ratio of carbonaceous chondrite meteorites found today. In contrast, comets have $D/H$ ratios that are significantly higher, and other classes of meteorites are almost entirely dry. Therefore, carbonaceous chondrites must have been the primary source of Earth's water.

Scientist 2
Earth's water was present from the beginning, trapped inside the mantle during Earth's initial accretion. High-pressure mantle minerals, such as ringwoodite, can store up to $1.5\%$ water by weight in the form of hydroxide ions ($OH^-$). As early Earth cooled, geological outgassing through volcanic eruptions released this water to the surface, creating the oceans. The similarity in $D/H$ ratios between Earth's oceans and carbonaceous chondrites is merely a reflection of the shared composition of the inner solar nebula during accretion, rather than evidence of late delivery.

Which of the following statements represents an underlying assumption of Scientist 1's hypothesis?

Researchers investigated the effects of ocean warming and acidification on the calcification rates of the coccolithophore *Emiliania huxleyi*. They grew cultures of the marine microalgae under various combinations of temperature, partial pressure of carbon dioxide ($pCO_2$), and salinity for 14 days. All other growth parameters, including light-dark cycles and nutrient concentrations, were held constant. The conditions for Trials 1–5 are shown in the table below:

In Trial 5, salinity was lowered to 30 psu to simulate the influx of fresh water from glacier melting, which is associated with warming oceans. To isolate and determine the specific effect of this reduced salinity on the calcification rate under projected future conditions of ocean warming and acidification, which of the other trials should be used as the control?

Tektites are small, glassy objects found in specific areas on Earth called strewn fields. Three scientists present hypotheses regarding the origin and formation of tektites.

Scientist 1
Tektites are terrestrial in origin, formed when large meteorites collided with Earth. The extreme kinetic energy of the impact melted local surface sediments (mostly quartz-rich sands). This molten silicate material was ejected high into the atmosphere, where it cooled rapidly in flight to form glass before falling back to Earth.

Scientist 2
Tektites originated on the Moon. Lunar volcanic eruptions propelled molten silicate magma at escape velocity into space. This material traveled through space and entered Earth's atmosphere. As the molten droplets fell through Earth's atmosphere, they underwent secondary melting due to atmospheric friction, followed by rapid cooling upon reaching the cooler lower atmosphere.

Scientist 3
Tektites are remnants of silicate-rich asteroids. When these asteroids entered Earth's atmosphere at high speeds, frictional heating caused the outer layers of the asteroid to melt. This molten silicate material sheared off into droplets, which cooled rapidly during flight through the atmosphere and fell to the ground as tektites.

Based on the descriptions of the three hypotheses, all three scientists would agree with which of the following statements regarding the formation of tektites?

Two students propose competing hypotheses regarding the rate of oxygen ($O_2$) gas production during the catalytic decomposition of hydrogen peroxide ($H_2O_2$) by a yeast suspension.

Student 1 Hypothesizes: The rate of $O_2$ production is directly proportional to the initial concentration of $H_2O_2$ because a higher concentration of reactant increases the frequency of collisions.

Student 2 Hypothesizes: The rate of $O_2$ production is limited by the number of active enzyme sites on the yeast cells. Once all active sites are saturated, the rate will reach a maximum value ($V_{max}$) and remain constant, regardless of further increases in $H_2O_2$ concentration.

The students perform five trials measuring the volume of $O_2$ gas produced in the first 60 seconds under various initial conditions. The results are shown in the table below:

Based on these results, which of the following statements best describes how one of the hypotheses should be modified to align with the experimental data?

Two competing models describe the evolutionary end-states of massive stars with initial progenitor masses between $20 M_{\odot}$ and $35 M_{\odot}$ ($M_{\odot}$ represents the solar mass).

*Model 1*: Core collapse initiates a weak shock wave that fails to eject the majority of the outer stellar envelope. Roughly $90\%$ of the envelope's mass falls back onto the newborn core within hours. This process yields a faint supernova with a small amount of ejected mass ($0.5$ to $2.0 M_{\odot}$) and a brief, low-luminosity electromagnetic transient.

*Model 2*: The iron core of the progenitor star is too massive to allow shock wave propagation. The star undergoes direct collapse, where the entire stellar mass falls directly into a black hole. No shock wave is generated, zero mass is ejected, and no electromagnetic emission is produced.

Astronomers recently observed three disappearing red supergiant stars in this mass range. The data collected from these observations are presented in the table below:

Based on this information, which of the observed stars provide data that support Model 2 and contradict Model 1?

### Origin of Earth's Water

Two hypotheses address the origin of Earth's surface oceans.

Hypothesis 1
During Earth's accretion from planetesimals in the inner solar nebula, the high temperatures from gravitational collapse and radioactive decay vaporized all local water. Because Earth's early gravitational field was too weak to retain these light volatile gases, this water vapor escaped into space, leaving the planet completely dry. Subsequently, during the Late Heavy Bombardment ($\approx 4.0$ to $3.8$ billion years ago), water was delivered to Earth's surface by carbonaceous chondrite meteorites. These meteorites are rich in water (up to $20\%$ by weight) and possess a deuterium-to-hydrogen ($D/H$) ratio ($\approx 1.5 \times 10^{-4}$) that is identical to that of Earth's modern oceans.

Hypothesis 2
Earth's water is primordial, originating from hydrated silicate minerals within the local planetesimals that accreted to form the planet. During the rapid accretion process, Earth's gravity was strong enough to retain the steam outgassed from its molten interior. Deep mantle reservoirs, insulated from surface vapor loss, preserved this primordial water. The $D/H$ ratio of this mantle water is lower ($\approx 1.2 \times 10^{-4}$) than that of modern surface water. Tectonic recycling and the preferential escape of lighter hydrogen isotopes to space over billions of years have gradually increased the surface $D/H$ ratio to its modern value of $1.5 \times 10^{-4}$.

According to the passage, Hypothesis 1 and Hypothesis 2 differ fundamentally in their assumptions regarding which of the following?