- Based on the data, what can be concluded?
Answer: Both tablets were effective at reducing bacteria, but Tablet A was more effective than Tablet B.
When you encounter scientific data comparison questions, focus on what the numbers actually tell you versus what might seem intuitive or absolute.
Looking at this water purification study, you need to compare the effectiveness percentages: Tablet A eliminated 99.5% of bacteria while Tablet B eliminated 92.0%. Both percentages are significantly high, indicating both tablets successfully reduce bacterial contamination. However, 99.5% is clearly greater than 92.0%, making Tablet A more effective.
Answer A correctly captures both key findings: both tablets work well at reducing bacteria, but Tablet A performs better. This reflects what the data actually shows.
Answer B is wrong because 92.0% elimination is quite effective—removing over 9 out of every 10 bacteria is far from "completely ineffective." Answer C makes an unsupported leap about safety. While Tablet A is highly effective at 99.5%, this doesn't mean the water is "entirely safe"—that would require 100% elimination plus consideration of other contaminants not tested. Answer D commits a mathematical error by assuming you can simply add percentages. Even if both tablets worked on different bacteria (which isn't stated), 99.5% + 92.0% doesn't equal 100% elimination.
Study tip: On GED science questions involving data comparison, stick to what the numbers directly show you. Avoid extreme conclusions like "completely ineffective" or "entirely safe" unless the data explicitly supports them. Also, remember that percentages don't add together in the way whole numbers do.
- What can be concluded from this experiment?
Answer: Exposure to intense UV light causes the degradation of this new plastic.
When you encounter experiments testing materials under different conditions, focus on what the data actually shows versus what it doesn't prove. This question tests your ability to draw valid conclusions from controlled experimental results.
The experiment clearly demonstrates that UV exposure caused significant changes to the plastic—it became brittle and lost 40% of its tensile strength, while the control samples (kept in darkness) remained unchanged. This direct comparison between experimental and control groups shows a clear cause-and-effect relationship between UV exposure and plastic degradation, making D correct.
Let's examine why the other options are flawed: A is wrong because the plastic clearly wasn't resistant to UV damage—it degraded significantly. This option makes an overly broad claim that contradicts the experimental evidence. B incorrectly generalizes the results beyond what was tested. The experiment only tested one specific type of plastic, so you cannot conclude that all plastics would react the same way. C misinterprets the control group results. The control samples showed "no change," meaning they maintained their original properties—this doesn't mean they became stronger.
Watch for this common pattern on science questions: experiments provide evidence for specific conclusions, but wrong answers often make claims that are too broad, too narrow, or completely unsupported by the data. Always ask yourself: "What does this experiment actually prove?" and avoid answers that go beyond what the evidence shows.
- What conclusion can be drawn from these results?
Answer: For this particular salt, solubility in water increases as the temperature increases.
When you encounter questions about solubility and temperature, focus on what the data directly tells you versus what it might imply about other factors or broader generalizations.
Looking at the experimental data, you can see a clear pattern: at 20°C, only 36 grams of salt dissolved, but at 80°C, 54 grams dissolved in the same amount of water. This direct comparison shows that higher temperature allowed more salt to dissolve, which is exactly what answer choice A states - for this particular salt, solubility increases with temperature.
Now let's examine why the other options are incorrect. Choice B confuses solubility (how much can dissolve) with dissolution rate (how fast it dissolves). The experiment measured maximum amounts that dissolved, not how quickly dissolution occurred. Choice C makes an overgeneralization - the data only tells us about one specific salt, not "all salt compounds." Some salts actually become less soluble at higher temperatures. Choice D misinterprets what's happening chemically. Dissolving is a physical process where the salt separates into ions; no new chemical compound forms between the salt and water.
The key distinction here is between what the data directly supports versus assumptions or broader claims. The experiment provides evidence only about this one salt's solubility behavior with temperature changes.
Study tip: On GED science questions involving experimental data, stick to conclusions that the evidence directly supports. Avoid answer choices that overgeneralize beyond the specific conditions tested or confuse related but distinct scientific concepts.
- What is the most logical conclusion based on the results of this study?
Answer: Getting eight hours of sleep is associated with better memory consolidation.
When you encounter scientific studies on the GED, focus on what the data actually shows versus what it might suggest about broader patterns. The key is distinguishing between what the evidence directly supports and what goes beyond the scope of the study.
Looking at this sleep and memory study, Group 1 (with 8 hours of sleep) recalled 85% of words while Group 2 (no sleep) recalled only 55%. This data directly demonstrates an association between getting adequate sleep and better memory performance, making choice A correct. The results show that sleep appears to help with memory consolidation - the process by which memories become more stable and retrievable.
Choice B assumes motivation differences between groups, but the study provides no evidence about student effort levels. You can't conclude this from memory performance alone. Choice C makes an overly specific claim about "exactly a 30% drop" and generalizes to "any amount of sleep deprivation," when the study only tested complete sleep deprivation versus 8 hours of sleep. Choice D uses absolute language ("only factor that ever affects") which is far too broad - the study only examined sleep's role, not all possible memory factors.
Remember that scientific conclusions should match the scope and specificity of the evidence presented. Watch for answer choices that make claims about motivation, exact percentages, or absolute statements when the data doesn't support such specificity. Stick to what the numbers actually demonstrate rather than unsupported assumptions.
- What is the most reasonable conclusion that can be drawn from these observations?
Answer: Ground swelling and changes in gas composition may be precursor signals to an eruption.
When you encounter questions about volcanic activity and scientific observations, focus on distinguishing between what the data directly supports versus unsupported generalizations or assumptions.
The scientists observed two specific changes before the eruption: ground swelling and increased sulfur dioxide emissions. These are factual observations that occurred in sequence with the eruption. Answer A correctly identifies these as potential precursor signals - observable changes that may indicate an upcoming eruption. This is a reasonable scientific conclusion because it's based directly on the documented pattern.
Answer B makes an overgeneralization by claiming "all volcanic eruptions" follow the exact same pattern with identical amounts of ground swelling. Scientific observations from one volcano cannot support such a broad claim about all volcanoes everywhere.
Answer C introduces information not provided in the passage. While earthquakes can be associated with volcanic activity, the passage mentions no earthquake data. This choice asks you to assume causation without evidence.
Answer D contains an absolute statement that's easily disproven. Volcanoes emit many different gases including water vapor, carbon dioxide, and hydrogen sulfide - not just sulfur dioxide.
For GED Science questions involving scientific observations, remember to stick closely to what the data actually shows. Correct answers typically reflect reasonable conclusions drawn directly from the evidence presented, while wrong answers often contain unsupported generalizations (like "all" or "only"), introduce outside information, or make claims beyond what the data can support.
- What is the most direct conclusion supported by this data?
Answer: There is a positive correlation between atmospheric CO2 concentration and average global temperature.
When you encounter data showing two variables changing together over time, you need to distinguish between correlation and causation. This question tests your ability to draw appropriate conclusions from observational data.
The passage describes a clear pattern: as atmospheric CO2 concentrations increased from 1960 to 2020, global temperatures also increased, and years with higher CO2 consistently matched years with higher temperatures. This describes a positive correlation—when one variable increases, the other tends to increase as well.
Answer D correctly identifies this relationship as a positive correlation, which is exactly what the data supports. The evidence shows the two variables moving together in the same direction consistently over 60 years.
Answer A reverses the suspected cause-and-effect relationship and uses absolute language ("sole cause") that goes far beyond what correlation data can prove. Correlation never proves causation, regardless of direction.
Answer B introduces volcanic eruptions, which aren't mentioned anywhere in the passage. This is a classic distractor that brings in outside knowledge about CO2 sources that isn't supported by the given data.
Answer C makes predictions about future trends ("will continue...forever") and assumes the rate of change will remain constant. The data only covers past observations and cannot support claims about future patterns or rates.
Remember: when analyzing scientific data, stick to what the evidence actually shows. Correlation questions often include tempting answers that claim causation or make predictions beyond the data's scope. Focus on describing the relationship you can observe, not explaining why it exists.
- Based on these results, what can be concluded about these materials?
Answer: Copper and aluminum are better conductors of heat than glass and wood.
This question tests your understanding of heat conduction, which is how thermal energy moves through materials. When you see experiments comparing how quickly heat travels through different substances, focus on the concept of thermal conductivity.
The experiment shows a clear pattern: copper heated up fastest, then aluminum, while glass and wood heated up very slowly. This directly demonstrates that copper and aluminum conduct heat much more effectively than glass and wood. Materials that allow heat to flow quickly are called good conductors, while those that resist heat flow are called insulators. Answer A correctly identifies this relationship.
Looking at the wrong answers: Answer B is too extreme - while glass and wood are poor conductors, they do transfer some heat, just very slowly. The experiment shows their temperatures did increase, proving heat transfer occurred. Answer C contradicts the experimental results entirely, since the data clearly shows different materials transfer heat at very different rates despite having identical dimensions. Answer D contains a fundamental misconception - it confuses conductors with insulators. Metals like copper and aluminum are excellent conductors (not insulators), which is exactly why they heated up quickly.
For GED Science questions about heat transfer, remember that metals are typically good conductors while non-metals (like wood, glass, plastic) are usually good insulators. This pattern appears frequently on the exam, so when you see experimental data showing different heating rates, immediately think about which materials would make better conductors versus insulators.
- What conclusion is best supported by these findings?
Answer: The different insect species appear to be adapted to different river habitats.
When you encounter ecology questions about species distribution, focus on the relationship between organisms and their environment. Different species have evolved specific adaptations that help them thrive in particular habitats.
The data shows a clear pattern: species A, B, and C dominate the slow-moving, muddy section, while species X, Y, and Z dominate the fast-moving, rocky section. This distribution strongly suggests that each group has evolved traits suited to their respective environments. Species in fast-moving water likely have adaptations like strong gripping structures or streamlined bodies, while those in slow-moving water might be better at burrowing in mud or filtering food from sediment. This supports answer A - the different insect species appear to be adapted to different river habitats.
Answer B incorrectly assumes predation is the primary factor, but predator-prey relationships wouldn't create such distinct, habitat-based distributions. Answer C jumps to pollution as an explanation without any evidence of contamination in the passage - the rocky, fast-moving section could simply be unsuitable habitat for species A, B, and C. Answer D contradicts the data entirely, as the study clearly shows different species distributions in different river sections.
For GED science questions about ecosystems, remember that species distributions usually reflect habitat preferences and evolutionary adaptations. When you see organisms segregated by environment type (like water speed or substrate), think adaptation rather than assuming more complex explanations like pollution or predation without supporting evidence.
- Based on this data, what is the most reasonable conclusion?
Answer: There is a correlation between the volume of vehicle traffic and nitrogen dioxide levels.
When you encounter data analysis questions on the GED Science exam, focus on what the data actually shows rather than making assumptions beyond what's presented. This question tests your ability to identify valid correlations from observational data.
The data reveals a clear pattern: weekdays show 45 ppb of nitrogen dioxide while weekends show only 20 ppb. The passage also confirms that vehicle traffic is "significantly heavier on weekdays." This creates a strong correlation between traffic volume and pollution levels - when traffic increases, nitrogen dioxide increases proportionally.
Answer D correctly identifies this correlation without overreaching beyond what the data supports. A correlation simply means two variables change together in a predictable pattern, which is exactly what we observe here.
Answer A is wrong because 20 ppb on weekends still represents pollution - the problem isn't eliminated, just reduced. Answer B misrepresents the data by claiming levels are "consistently high" when weekend levels are less than half of weekday levels. The word "dangerous" also goes beyond what the data tells us about health impacts. Answer C makes an unsupported assumption by claiming no other pollution sources exist. The data only addresses nitrogen dioxide from vehicles, not other pollutants or sources.
Remember that on GED Science questions involving data interpretation, stick to what the numbers actually demonstrate. Look for correlations (variables that change together) rather than jumping to conclusions about causation or making claims beyond the scope of the presented evidence. The most defensible scientific conclusion is usually the most conservative one.
- What is the best conclusion that can be drawn from this observation?
Answer: Adding more sugar to water increases the water's density.
When you encounter questions about objects floating or sinking, you're dealing with density and buoyancy. The key principle is that an object will float if it's less dense than the liquid it's in, and sink if it's more dense.
In this experiment, the egg sinks in Solution A (10g sugar in 100mL water) but floats in Solution B (20g sugar in 100mL water). Since the same egg behaves differently in these two solutions, the solutions themselves must have different densities. The egg must be denser than Solution A but less dense than Solution B.
This tells us that Solution B has a higher density than Solution A. The only difference between the solutions is that Solution B contains more dissolved sugar. Therefore, adding more sugar to water increases the water's density, making answer C correct.
Let's examine why the other answers are wrong: Answer A reverses the density relationships—if the egg were less dense than Solution A, it would float in that solution too. Answer B suggests the egg's mass changed, but mass is an intrinsic property that doesn't change when you move an object between solutions. Answer D contradicts the experimental evidence, since the egg clearly floats in the more concentrated sugar solution.
Remember: When analyzing buoyancy problems on the GED, focus on density differences between the object and the liquid. The denser liquid can support less dense objects, while less dense liquids cannot support denser objects.
- Which conclusion is best supported by the data from this study?
Answer: As the acidity of the water increases, the germination rate of lettuce seeds decreases.
When you encounter data analysis questions on the GED Science exam, focus on identifying patterns and relationships in the given data rather than making assumptions beyond what's directly shown.
Looking at this germination study, you need to examine the relationship between pH levels and germination rates. The data shows a clear inverse relationship: as pH decreases (meaning acidity increases), germination rates consistently drop. At pH 7 (neutral), 95% of seeds germinated. At pH 5 (moderately acidic), only 60% germinated. At pH 3 (very acidic), just 10% germinated. This steady decline from 95% to 60% to 10% demonstrates that increasing acidity correlates with decreasing germination success, making answer C correct.
Answer A contradicts the data entirely—the seeds performed best in neutral conditions, not highly acidic ones. Answer B makes an unsupported absolute claim; the study shows 10% of seeds did germinate at pH 3, and we have no data about pH levels below 3. Answer D ignores the dramatic differences in germination rates (95% vs. 10% is highly significant) and inappropriately generalizes from lettuce seeds to "any plant seeds."
Remember that data analysis questions test your ability to identify trends and draw conclusions that stay within the bounds of what's actually measured. Avoid answers that make absolute statements ("no seeds will...") or overgeneralize beyond the study's scope. Focus on the specific relationship the data reveals.
- Based on the principle of superposition and the fossil evidence, what can be concluded?
Answer: The environment of this location changed over time from a marine to a terrestrial one.
When you encounter questions about rock layers and fossils, you're dealing with two fundamental geological principles: superposition (older layers are below younger ones in undisturbed rock) and using fossils to interpret ancient environments.
Looking at this sequence from bottom to top, you can read it like a timeline. The lowest layer contains marine fossils (trilobites), indicating this area was once underwater. The middle layer has ferns and amphibians, suggesting a swampy, transitional environment between water and land. The top layer contains dinosaurs, which lived in terrestrial environments. This progression shows the environment changed from marine to terrestrial over geological time, making D correct.
Choice A is wrong because the principle of superposition tells us these organisms lived at different times, not simultaneously in different environments. The layers represent different time periods, not different locations.
Choice B incorrectly suggests direct evolution from trilobites to amphibians. While evolution did occur, you cannot conclude that local amphibians evolved directly from local trilobites just because their fossils appear in successive layers. Evolution is more complex than simple linear progression at one location.
Choice C completely misinterprets superposition. Since dinosaur fossils are in the upper (youngest) layer, dinosaurs were actually among the last organisms to live here, not the first.
Remember: Rock layers are like pages in Earth's history book. Always read from bottom (oldest) to top (youngest) to understand how environments and life changed through time.
- What is the most logical conclusion that can be drawn from these observations?
Answer: The moths' nocturnal behavior is likely an adaptation to avoid daytime predators.
This question tests your understanding of evolutionary adaptations and how organisms respond to environmental pressures, particularly predation. When you see behavioral patterns that seem to correlate with predator activity, think about how natural selection shapes survival strategies.
The key insight here is recognizing the relationship between the moths' behavior and their predators' activity patterns. The moths are active at night when their bird predators are inactive, and they rest during the day when the birds are hunting. This temporal separation isn't coincidental—it's likely an evolved adaptation that increases the moths' survival chances by reducing encounters with predators.
Answer D correctly identifies this as an adaptive behavior. Natural selection would favor moths that avoid active predation periods, making nocturnal behavior an advantageous trait that gets passed on to offspring.
Answer A incorrectly assumes the moths can't see during the day. Many moths actually have functional vision in daylight, so this explanation oversimplifies the behavior. Answer B makes an absolute claim that's unsupported—just because their main predators (birds) aren't active at night doesn't mean the moths face no nighttime threats from other predators like bats or spiders. Answer C shifts focus to what would make the birds more successful, but this doesn't address what we can conclude from the observed moth behavior.
For GED science questions about animal behavior, always look for connections between an organism's actions and its environment, especially predator-prey relationships. Behaviors that seem to minimize risk or maximize survival are usually adaptations shaped by natural selection.
- What can be concluded from this simple experiment?
Answer: The rate of photosynthesis in this plant decreases as light intensity decreases.
This experiment tests your understanding of how environmental factors affect the rate of photosynthesis. When you see questions about controlled experiments measuring biological processes, focus on what variable was changed and how the measured outcome responded.
The scientist changed one variable—light intensity (moving the light closer or farther away)—and measured oxygen bubble production as an indicator of photosynthesis rate. With bright, close light, the plant produced 30 bubbles per minute. When light intensity decreased (light moved farther away), bubble production dropped to 12 bubbles per minute. This shows a clear relationship: as light intensity decreases, the rate of photosynthesis decreases, making choice B correct.
Choice A is wrong because photosynthesis still occurred when the light was farther away—just at a slower rate (12 bubbles vs. 30). The plant doesn't need extremely bright light to photosynthesize at all. Choice C incorrectly identifies water as the limiting factor, but the experiment kept water constant and only changed light intensity. Choice D contradicts basic photosynthesis knowledge and the experimental evidence—oxygen bubbles were clearly produced, proving oxygen is a product of photosynthesis in aquatic plants.
For GED science questions involving controlled experiments, always identify what variable was manipulated and trace how it affected the measured outcome. Don't get distracted by absolute statements (like "only" or "never") in answer choices—biological processes rarely work in such extremes. Focus on relationships and trends in the data.
- Which conclusion is best supported by the findings of this study?
Answer: Weight-bearing exercise appears to be associated with maintaining higher bone density.
When analyzing research studies, you need to distinguish between what the data actually shows versus broader claims that go beyond the evidence. This question tests your ability to identify conclusions that are directly supported by the study's findings.
The study compared two specific groups: people who did weight-bearing exercise versus those with sedentary lifestyles. The results showed that the exercise group had higher bone density and fewer fractures. This creates a clear association between weight-bearing exercise and better bone health outcomes.
Answer D correctly captures this relationship by stating that weight-bearing exercise "appears to be associated with" higher bone density. The word "appears" acknowledges that this is observational data, and "associated with" indicates correlation without claiming absolute causation.
Answer A is wrong because the study didn't examine diet at all - you can't conclude anything about factors that weren't tested. Answer B makes an absolute claim ("no one who exercises will ever") that goes far beyond what the data shows. Even if the exercise group had fewer fractures, this doesn't mean zero fractures occurred. Answer C claims sedentary lifestyle is the "single cause of all bone density loss," which is an extreme overstatement. The study only compared two groups and doesn't account for other factors like genetics, medical conditions, or age-related changes.
On GED Science questions about research studies, watch for answer choices that make absolute statements or draw conclusions about factors not tested in the study. The correct answer will typically match the scope and limitations of the actual research findings.
- What is the most reasonable conclusion to draw from this study?
Answer: The data suggests a link between regular moderate exercise and a reduction in blood pressure.
When analyzing scientific studies, you need to distinguish between what the data actually shows versus overgeneralized claims. This study uses a controlled experiment design with two groups to test the effect of moderate exercise on blood pressure.
The data shows that the exercise group experienced a 10-point decrease in average blood pressure while the control group (no exercise change) remained unchanged. This pattern suggests a connection between the exercise intervention and blood pressure reduction, making option D correct. The study provides evidence of a link, which is exactly what well-designed experiments can demonstrate.
Option A is wrong because the study shows an average decrease, not a guarantee for every individual. Scientific studies reveal trends and probabilities, not absolute certainties for all people. Option B incorrectly claims exercise is the "only" effective method for lowering blood pressure. The study only tested exercise versus no exercise - it didn't compare exercise to other potential treatments like medication or diet changes. Option C makes the error of assuming all physical activity will produce identical results. The study specifically tested 30 minutes of moderate exercise three times weekly, not "any amount and type" of activity.
Remember that on GED Science questions about studies, look for conclusions that match the scope and limitations of the actual data collected. Avoid answers that use absolute language like "guaranteed," "only way," or "always" - real scientific studies typically support more measured conclusions about relationships and trends rather than universal certainties.
- What is the most logical conclusion based on these astronomical observations?
Answer: Star X is significantly farther away from Earth than Star Y.
When you encounter astronomy questions about starlight and distance, remember that two key principles work together: brightness decreases with distance, and light shifts toward red when objects move away from us (redshift).
Since both stars have the same intrinsic brightness but Star X appears dimmer on Earth, Star X must be farther away. This follows the inverse square law - light intensity decreases with the square of distance. The redshift of Star X's light provides additional evidence: as the universe expands, more distant objects move away from us faster, causing greater redshift. Both observations point to the same conclusion.
Let's examine why the other answers fail. Choice B suggests Star Y is larger and hotter, but the passage explicitly states both stars are "of the same type and intrinsic brightness," eliminating this possibility. Choice C proposes different galaxies, but you don't need such an extreme distance difference to explain the observations - stars within our own galaxy can vary enormously in distance from Earth. Choice D reverses the redshift concept: if Star X were moving toward Earth, its light would be blueshifted, not redshifted.
The correct answer is A - Star X is significantly farther from Earth than Star Y.
For GED Science astronomy questions, remember this pattern: when comparing similar objects, differences in observed brightness usually indicate differences in distance. Combined with redshift data, you can confidently determine relative distances without needing complex calculations.
- Based on this data, which conclusion is the most valid?
Answer: Smoking cigarettes is associated with a decrease in average lifespan.
When analyzing scientific data about correlations and causation, you need to carefully distinguish between what the data actually shows versus broader claims that go beyond the evidence.
The study presents clear data showing a pattern: as smoking increases, average lifespan decreases (78 years for non-smokers, 71 for moderate smokers, 65 for heavy smokers). This demonstrates an association between smoking and reduced lifespan, making D the correct answer. The data consistently shows that higher smoking levels correlate with shorter average lifespans.
Looking at why the other options fail: A claims smoking is the "only factor" determining lifespan, which is an extreme overstatement—many factors affect lifespan including genetics, diet, exercise, and medical care. B misinterprets what "average" means; saying every heavy smoker dies at 65 confuses an average with an absolute prediction. Some heavy smokers will live longer or shorter than 65 years. C contradicts the data directly—moderate smokers averaged 7 fewer years than non-smokers, clearly showing a negative impact.
The key distinction here is between correlation (what this study shows) and causation (which would require controlled experiments). The study reveals an association but doesn't prove smoking directly causes shorter lifespans, though that's the most reasonable interpretation.
GED Science tip: Watch for answer choices that use absolute language like "only," "every," or "always" when interpreting data—these are usually incorrect because scientific data typically shows trends and averages, not universal rules.
- What conclusion is best supported by the data?
Answer: For this reaction, the rate doubles for every 10°C increase in temperature.
When you encounter questions about reaction rates and temperature, you're dealing with a fundamental principle of chemistry: most chemical reactions speed up as temperature increases because higher temperatures give molecules more kinetic energy to collide and react.
Let's examine the data systematically. At 10°C, the reaction takes 120 seconds. At 20°C (a 10°C increase), it takes 60 seconds—exactly half the time, meaning the rate doubled. At 30°C (another 10°C increase), it takes 30 seconds—again half the previous time, so the rate doubled again. This consistent pattern shows that for every 10°C temperature increase, the reaction rate doubles, making choice A correct.
Choice B is backwards—the data clearly shows that increasing temperature increases the rate, not decreasing it. When temperature dropped from 30°C to 10°C, the reaction time increased from 30 to 120 seconds, meaning it slowed down.
Choice C contradicts all the evidence. The reaction times changed dramatically with temperature (120s → 60s → 30s), proving temperature definitely affects the rate.
Choice D makes an unfounded prediction. While we can see the doubling pattern in our data range, we have no evidence about what happens at 40°C. The pattern suggests it would take about 15 seconds, not stop completely.
For GED Science questions involving data tables, always look for mathematical relationships between variables. Calculate the ratios or differences systematically rather than just eyeballing the numbers—this helps you spot patterns like the doubling effect seen here.
- Based on this information, what is the most logical conclusion?
Answer: The antibiotic is effective against Bacterium X but not against Bacterium Y.
When you encounter questions about antibiotic effectiveness, focus on what the experimental data actually shows rather than making broad assumptions beyond the evidence.
The experimental results are clear: the antibiotic reduced Bacterium X by 99.9% (highly effective) while Bacterium Y's population remained stable (no effect). This directly demonstrates that the antibiotic works against one bacterium but not the other, making B the correct answer.
Let's examine why the other choices are flawed:
A suggests that Bacterium Y is more dangerous to humans, but the passage provides no information about pathogenicity or human health effects—only about antibiotic response. You cannot determine how dangerous a bacterium is based solely on antibiotic resistance.
C makes an overgeneralization by claiming ALL antibiotics will be ineffective against Bacterium Y. The experiment only tested one antibiotic. Different antibiotics work through different mechanisms, so resistance to one doesn't guarantee resistance to all others.
D similarly overgeneralizes by claiming this antibiotic will work against ALL other bacteria except Bacterium Y. The experiment only tested two bacterial species, so you cannot make conclusions about the antibiotic's effectiveness against other untested bacteria.
Study tip for GED Science: When analyzing experimental results, stick to what the data directly shows. Avoid answer choices that make sweeping generalizations beyond the scope of the experiment or introduce information not provided in the passage. Focus on the specific comparison being made.
