Name:
Date:
Class:
How to use this worksheet. Read each passage, graph, and data table before you answer. Choose the
best answer and write its letter on the answer line.
- Every question has a Nudge — a hint about how to think it through. It does not give the answer away. Try the question first; read the nudge only if you get stuck.
- After each answer, write why you picked it in your own words. Base every answer on evidence in the passage or the data — not on memory or opinion.
- No calculator is needed. Suggested time: about 55 minutes, but accuracy and reasoning matter more than speed.
STIMULUS 1 · LIFE SCIENCECellular Respiration and Photosynthesis
Plants and animals both need energy to survive, but they obtain it in different ways. Plants use photosynthesis to capture energy from sunlight and store it as chemical energy in glucose, a type of sugar. This process also releases oxygen as a byproduct. Animals, and plants themselves, use cellular respiration to break down glucose and release its stored energy for use by the cell. Cellular respiration requires oxygen and produces carbon dioxide and water as byproducts. In effect, photosynthesis and cellular respiration are complementary processes: the products of one process are the raw materials used by the other. This cycle helps explain why plants are often described as essential to maintaining the balance of oxygen and carbon dioxide in Earth's atmosphere.
1.What is the central idea of this passage?
- A. Plants only consume energy and never produce it.
- B. Photosynthesis and cellular respiration are complementary processes whose products feed into one another.
- C. Animals do not require oxygen for any biological process.
- D. Photosynthesis and cellular respiration are unrelated and occur independently.
Nudge — A central idea must cover the whole passage, not one detail. Watch for absolute words like only, never, and unrelated — they often make an option too extreme to fit a passage about two processes working together.
My answer:
Why I picked this (in my own words):
2.According to the passage, what happens during photosynthesis?
- A. Cellular respiration absorbs sunlight energy directly.
- B. Animals perform photosynthesis to create their own food.
- C. Sunlight energy is captured and stored in glucose, releasing oxygen as a byproduct.
- D. Glucose is broken down to directly produce sunlight.
Nudge — "According to the passage" means the answer is written there. Find the sentence about photosynthesis and check what goes in and what comes out. Rule out any option that swaps photosynthesis with respiration or names the wrong performer.
My answer:
Why I picked this (in my own words):
3.According to the passage, what does cellular respiration do?
- A. It breaks down glucose using oxygen, releasing energy along with carbon dioxide and water.
- B. It creates glucose from carbon dioxide and water.
- C. It occurs only in plant cells, never in animal cells.
- D. It releases oxygen as its primary byproduct.
Nudge — Locate the sentence describing respiration and list its inputs and byproducts. Careful: one option describes photosynthesis instead, and another uses an absolute (only… never) the passage contradicts.
My answer:
Why I picked this (in my own words):
4.The relationship described in this passage is best understood as an example of which broader principle?
- A. The theory of natural selection.
- B. The law of universal gravitation.
- C. The process of mitosis.
- D. The law of conservation of mass and energy, as matter and energy cycle between organisms rather than being created or destroyed.
Nudge — This one asks you to zoom out to the bigger principle the passage illustrates. Three of the choices come from unrelated science units, so cross those out first, then check which remaining principle fits the way the two processes keep exchanging the same materials.
My answer:
Why I picked this (in my own words):
5.A sealed glass terrarium contains only soil, a healthy green plant, and a small amount of trapped air, with no gas exchange with the outside. Based on the passage, which gas would you expect to be most depleted in the terrarium's air if the plant were kept in complete darkness for several days (preventing photosynthesis)?
- A. Oxygen, because the plant would continue cellular respiration (consuming oxygen) without photosynthesis (which produces oxygen) to replace it.
- B. Carbon dioxide, because respiration only produces oxygen in the dark.
- C. Nitrogen, because plants convert nitrogen into glucose during respiration.
- D. No gases would change, since photosynthesis and respiration do not affect gas levels in a sealed environment.
Nudge — Apply the passage to a new situation. In darkness, which of the two processes stops and which keeps running? Then trace which gas keeps getting used up with nothing to refill it. Cross out any option that invents a process the passage never mentions.
My answer:
Why I picked this (in my own words):
6.Why might the passage describe plants as “essential to maintaining the balance of oxygen and carbon dioxide” in the atmosphere?
- A. Because animals do not produce carbon dioxide at all.
- B. Because plants are the only organisms that perform cellular respiration.
- C. Photosynthesis continually replenishes oxygen and consumes carbon dioxide, balancing what respiration removes and adds.
- D. Because plants prevent all animals from breathing oxygen.
Nudge — "Balance" points to one process undoing what the other does. Find the option that describes that give-and-take. Watch the extreme words (only, all, at all) — a balance can't rest on an absolute.
My answer:
Why I picked this (in my own words):
STIMULUS 2 · DATA ANALYSISDeer Population on an Island with Limited Food Resources
A small population of deer was introduced to an island that has a limited supply of food and other resources. Researchers counted the herd every two years for sixteen years. The data below show how the population changed over time. A dashed reference line marks the island's approximate carrying capacity — about 378 deer — the largest herd the island's resources can support over time.
Table 1. Deer population on the island, recorded every 2 years
| Time (years) |
Deer population |
Change from previous count |
| 0 | 20 | — |
| 2 | 45 | +25 |
| 4 | 95 | +50 |
| 6 | 180 | +85 |
| 8 | 290 | +110 |
| 10 | 350 | +60 |
| 12 | 370 | +20 |
| 14 | 375 | +5 |
| 16 | 376 | +1 |
Approximate carrying capacity of the island ≈ 378 deer. Illustrative data modeled on typical logistic population growth in a resource-limited environment.
7.According to the graph, during which time interval did the deer population increase the most?
- A. 0 to 2 years
- B. 6 to 8 years
- C. 10 to 12 years
- D. 14 to 16 years
Nudge — "Increase the most" is about the change between two counts, not the totals. The last column already does the subtraction for each interval — compare those change values and find the largest.
My answer:
Why I picked this (in my own words):
8.Which statement best describes the overall pattern shown in the graph?
- A. The population grew at a constant, unchanging rate for all 16 years.
- B. The population doubled every two years for the entire period shown.
- C. The population declined steadily throughout the entire 16-year period.
- D. The population grew rapidly at first, then leveled off as it approached a maximum sustainable size.
Nudge — Describe the shape from start to finish. Do the change values stay the same, keep doubling, go negative, or grow then shrink toward zero? Test each option against the whole table, not just one row.
My answer:
Why I picked this (in my own words):
9.Based on the graph, which explanation best accounts for why the deer population growth slowed dramatically after year 10?
- A. The population was approaching the limit of food and resources the island could support, known as its carrying capacity.
- B. The deer stopped reproducing entirely after year 10.
- C. A new predator was introduced to the island at year 10.
- D. The graph's data after year 10 is inaccurate and should be ignored.
Nudge — Connect the slowdown in the data to what the passage tells you about the island's resources. Rule out any option that invents an event the data doesn't show, or that tells you to ignore the evidence.
My answer:
Why I picked this (in my own words):
10.Based on the graph, which statement is most accurate about the deer population between years 14 and 16?
- A. It grew faster than at any other point on the graph.
- B. It dropped sharply due to disease.
- C. It grew by only 1 deer, nearly leveling off near the island's carrying capacity.
- D. It returned to its starting value from year 0.
Nudge — Read the two counts at years 14 and 16 and find the difference. How big is that change compared with the others? Cross out any option describing a dramatic rise, drop, or reset the numbers don't support.
My answer:
Why I picked this (in my own words):
11.If this trend continues, which outcome would be most consistent with the pattern shown in the graph?
- A. The population will continue doubling every two years indefinitely.
- B. The population will suddenly drop to zero.
- C. The population will keep increasing at the same rate as between years 6 and 8.
- D. The population will likely stabilize at or near its current level, close to the island's carrying capacity.
Nudge — Look at what the change values are doing in the most recent intervals, then extend that same shape forward. Is the herd still rising fast, crashing, or flattening out? Pick the projection that matches the latest trend, not an earlier one.
My answer:
Why I picked this (in my own words):
12.This pattern of rapid early growth followed by leveling off near a resource-limited maximum is best described by which concept?
- A. Natural selection acting on random mutations.
- B. A population reaching its environment's carrying capacity.
- C. Cellular respiration.
- D. Photosynthesis.
Nudge — Match the described shape — fast growth that flattens at the most an environment can support — to its vocabulary term. Two options belong to Stimulus 1's topic and one is a different biology idea; eliminate the concepts that have nothing to do with a population hitting a resource limit.
My answer:
Why I picked this (in my own words):
STIMULUS 3 · PHYSICAL SCIENCEChemical Reactions and Conservation of Mass
A chemical reaction occurs when substances, called reactants, interact to form new substances, called products. During any chemical reaction, atoms are rearranged, but no atoms are created or destroyed. This is known as the law of conservation of mass: the total mass of the reactants must equal the total mass of the products. For example, when methane gas burns in the presence of oxygen, it produces carbon dioxide and water. Although the substances look completely different before and after the reaction, the same number and type of atoms are present at the start and at the end; they have simply been rearranged into new molecules. This is why chemical equations must always be balanced, with equal numbers of each type of atom on both sides of the equation.
13.What is the main idea of this passage?
- A. Chemical reactions destroy a small amount of matter every time they occur.
- B. In a chemical reaction, atoms are rearranged into new substances, but the total mass and number of atoms stays the same.
- C. Reactants and products always have an identical appearance.
- D. Burning methane gas creates entirely new atoms that did not exist before.
Nudge — The main idea should hold across the whole passage. Test each option against the passage's repeated claim that atoms are neither created nor destroyed — three options contradict it directly.
My answer:
Why I picked this (in my own words):
14.According to the passage, what happens to atoms during a chemical reaction?
- A. They are destroyed and replaced with new atoms.
- B. They disappear temporarily and then reappear.
- C. They are rearranged into new substances, but not created or destroyed.
- D. They only rearrange in reactions involving gases.
Nudge — Find the exact sentence about what happens to atoms and read it word for word. Rule out options that add a condition (like "only in gases") the passage never states, or that contradict the "not created or destroyed" wording.
My answer:
Why I picked this (in my own words):
15.According to the passage, why must chemical equations be balanced?
- A. Because balancing makes reactions happen faster.
- B. Because unbalanced equations are illegal to write.
- C. Because balancing changes how many atoms exist in the universe.
- D. Because the same number of each type of atom must appear on both sides, reflecting that mass is conserved.
Nudge — The passage gives the reason in its last sentence — locate it. Then eliminate options that are absurd or that claim balancing changes reality rather than simply reflecting it.
My answer:
Why I picked this (in my own words):
16.Based on the passage, if 16 grams of methane react completely with oxygen gas, and the reaction produces 44 grams of carbon dioxide, which statement must be true about the total mass of water also produced and the oxygen used?
- A. Some mass must have been destroyed in the reaction.
- B. The combined mass of methane and oxygen used must equal the combined mass of carbon dioxide and water produced, since total mass is conserved.
- C. The mass of water produced has no relationship to the mass of the reactants.
- D. Oxygen is not actually involved in this reaction.
Nudge — You don't need to calculate the exact grams of water. Apply the passage's core rule — everything that starts must add up to everything that ends. Cross out options that break that rule or deny a reactant the passage clearly names.
My answer:
Why I picked this (in my own words):
17.A student observes a reaction in a sealed, weighed container and notices the total mass measured is exactly the same before and after the reaction occurs. Based on the passage, this observation is:
- A. A violation of the law of conservation of mass.
- B. Impossible, since chemical reactions always change total mass.
- C. Evidence that no chemical reaction actually took place.
- D. Consistent with the law of conservation of mass, since atoms are rearranged, not created or destroyed.
Nudge — Ask whether "same mass before and after" matches the law the passage describes, or breaks it. Be careful with options built on an absolute like always — the passage tells you what mass should do.
My answer:
Why I picked this (in my own words):
18.This passage is best understood as an explanation of which scientific principle?
- A. The law of conservation of mass.
- B. The law of conservation of energy.
- C. The theory of plate tectonics.
- D. The process of natural selection.
Nudge — Name the single idea the whole passage is built around. Two options come from unrelated units; of the two "conservation" choices, decide whether the passage is tracking mass (atoms) or energy.
My answer:
Why I picked this (in my own words):
STIMULUS 4 · EARTH & SPACE SCIENCEThe Water Cycle
Water on Earth continuously moves through a process called the water cycle. Energy from the sun causes water at the surface of oceans, lakes, and rivers to evaporate, turning liquid water into water vapor that rises into the atmosphere. As water vapor rises and cools, it condenses into tiny droplets, forming clouds. When these droplets combine and become heavy enough, they fall back to Earth as precipitation, such as rain or snow. Some of this water soaks into the ground, becoming groundwater, while some flows over land as runoff, eventually returning to rivers, lakes, and oceans. This continuous cycle redistributes fresh water across the planet and plays a key role in shaping weather and climate patterns.
19.What is the main idea of this passage?
- A. Water on Earth disappears permanently once it evaporates.
- B. The water cycle is a continuous process that moves water between the surface and the atmosphere, redistributing fresh water across the planet.
- C. Precipitation only occurs in the form of snow.
- D. Groundwater is unrelated to the rest of the water cycle.
Nudge — A main idea covers the whole cycle, not one stage. Watch the absolute words (permanently, only, unrelated) — a passage about a continuous, connected cycle rarely rests on any of them.
My answer:
Why I picked this (in my own words):
20.According to the passage, what causes liquid water to evaporate from oceans, lakes, and rivers?
- A. Pressure from the atmosphere.
- B. The gravitational pull of the moon.
- C. Cold temperatures at the surface.
- D. Energy from the sun.
Nudge — This is stated almost word for word near the start of the passage. Find the sentence about evaporation and read what it names as the cause. Don't substitute outside knowledge for what the text actually says.
My answer:
Why I picked this (in my own words):
21.Based on the passage, what happens to water vapor as it rises and cools in the atmosphere?
- A. It condenses into droplets that form clouds.
- B. It disappears completely.
- C. It immediately falls back to Earth as runoff.
- D. It turns directly into groundwater.
Nudge — Follow the sentence that begins with vapor rising and cooling — the passage says exactly what it becomes next. Rule out options that skip stages of the cycle or claim the vapor simply vanishes.
My answer:
Why I picked this (in my own words):
22.A region experiences an unusually long period without rain, and its rivers and groundwater levels both drop significantly. Based on the passage, which explanation best accounts for this?
- A. The water cycle has permanently stopped in that region.
- B. Evaporation has stopped occurring anywhere on Earth.
- C. Precipitation has temporarily stopped returning water to the surface, so less water is available to become runoff and soak into the ground as groundwater.
- D. Groundwater levels are completely unrelated to precipitation patterns.
Nudge — Apply the cycle to a new scenario. If one stage pauses, trace what happens downstream to runoff and groundwater. Eliminate options with extreme claims like permanently stopped or anywhere on Earth that go beyond one dry region.
My answer:
Why I picked this (in my own words):
23.Which inference about runoff and groundwater is best supported by the passage?
- A. Runoff and groundwater are entirely separate systems with no shared source.
- B. Groundwater forms only from ocean water directly, not from precipitation.
- C. Runoff never reaches rivers, lakes, or oceans.
- D. Both runoff and groundwater originate from precipitation that falls to Earth's surface.
Nudge — An inference must still be grounded in the text. Find the sentence where precipitation splits two ways and ask what both paths start from. Three options separate them or contradict "eventually returning" — check each against the passage.
My answer:
Why I picked this (in my own words):
24.Which statement best summarizes the overall point of the passage?
- A. The water cycle is a one-way process that only moves water from the ground to the atmosphere.
- B. Precipitation is the only stage of the water cycle that matters for climate.
- C. The continuous movement of water through evaporation, condensation, and precipitation redistributes fresh water and influences weather and climate.
- D. The water cycle has no connection to weather patterns.
Nudge — A summary captures the big picture, not a single stage. Look for the option that ties the whole cycle to its larger role. Reject any option that shrinks the cycle to one direction, one stage, or "no connection."
My answer:
Why I picked this (in my own words):
Extended Response
In a well-developed response of 4–6 paragraphs, explain how natural systems maintain balance or change over time in response to inputs, limits, or disturbances. Use specific evidence from at least two of the sources in this test. Include a clear thesis; reference ideas from at least two stimuli (for example, photosynthesis/respiration, population growth and carrying capacity, conservation of mass, or the water cycle); explain at least one specific mechanism in detail — how a system responds when an input changes or a limit is reached; and end with a concluding statement connecting your examples to a general scientific principle. (Recommended time: 30 minutes.)
Nudge — Plan before you write. (1) State a thesis that names a system staying in balance or changing over time. (2) Pull evidence from two stimuli — for the deer, quote specific numbers from Table 1 (for example, how the change per interval shrinks toward the carrying-capacity line). (3) Explain one mechanism step by step, such as how growth slows as a population nears a resource limit, or how mass stays equal while atoms rearrange. (4) Close by linking your examples to a broader principle.
Reflection
Which questions did you need the nudge for? Which type was hardest — reading a passage, interpreting the data table, or applying a concept to a new scenario (like the terrarium or the drought)? Name one science topic or skill you plan to review before test day, and one strategy that worked well for you.
FOR INSTRUCTOR USE — NOT FOR DISTRIBUTION
Mentor Guide
How to run this worksheet, use the nudges, and review work without an answer key
1. What the nudges are (and are not)
Each question carries a Nudge — a printed hint about how to attack the question. A nudge never states or implies the answer; it names the strategy (find the sentence, compare the change values, watch for absolute words, apply the passage to the new scenario). A student who is stuck gets unstuck by reasoning, not by being told. Encourage students to attempt each item first and read the nudge only when they cannot start. Over time the nudges become the student's own internal checklist and can be withdrawn.
2. Reviewing WITHOUT an answer key
This sheet is deliberately printed with no answer key and no answers anywhere. Review it with the student, using the passages and Table 1 as the authority instead of a key:
- For every question, ask "which sentence, which number?" Have the student point to the exact evidence — even for answers they feel sure about. A right answer for the wrong reason is a future wrong answer.
- Use the "Why I picked this (in my own words)" lines as your diagnostic. If the reasoning is sound, the letter almost always follows; if the reasoning is shaky, coach the reasoning, not the letter.
- When a student is wrong, resist supplying the answer. Send them back to the passage or table to test each option against the evidence until they self-correct.
- For the data questions, cover the "Change from previous count" column and have the student compute a difference themselves before revealing it.
3. The skills this set is really testing
- Central idea vs. detail: Q1, 13, 19, 24. Teach the test "does this cover the whole passage?" and the absolute-word check (only, never, always, unrelated).
- Reading it straight from the text: Q2, 3, 14, 15, 20, 21. The answer is stated; the skill is locating the sentence and not swapping two processes or stages.
- Interpreting the data table/graph: Q7, 8, 10, 11. Insist the student point to actual counts and changes. "Which years? Which number?" is the whole lesson.
- Applying a concept to a new scenario: Q5 (sealed terrarium), Q9/12 (carrying capacity), Q16/17 (conservation of mass), Q22 (drought). Model the move from passage rule to new situation.
4. Running the session
- Read each passage aloud together if it helps — it removes a decoding barrier so effort goes into the science, not the sentences. Connect topics to real life (gardening and photosynthesis, cooking and reactions, weather and the water cycle).
- Do Table 1 as a group before Q7: cover the change column and ask students to predict where growth is fastest and where it flattens, then reveal.
- Note on carrying capacity: this concept also appears on the Limiting Factors sheet. Here the passage, data, and questions are different (a deer herd on a resource-limited island), so use it to reinforce, not repeat — ask students to connect the flattening curve to a resource limit.
- Suggested pacing: Stimulus 1 + Q1–6, break, Stimulus 2 + Table + Q7–12, break, Stimuli 3–4 + Q13–24, then the extended response (which can be homework). The real GED Science section is 90 minutes; build pacing habits of roughly 2–3 minutes per question, but put accuracy and reasoning first.
- Begin feedback with what the student did well, give credit for reasoning and effort, and allow flexible responses (oral answers, drawings, sentence starters) when writing is difficult.
5. Extended Response — scoring rubric (0–4)
Score the essay holistically. Award the level that best matches the response overall — it need not meet every bullet at a level to earn that score. Credit specific, accurate use of evidence (for example, exact numbers from Table 1) above polished prose.
4 · AdvancedClear, well-developed thesis about balance or change in a natural system; specific, accurate evidence from at least two sources; explains at least one mechanism in real detail (e.g., how growth slows near carrying capacity; how mass is conserved while atoms rearrange); logically organized with a conclusion tied to a general principle; few or no errors that interfere with meaning.
3 · ProficientIdentifiable thesis, though development may be uneven; uses evidence from at least two sources but analysis is more descriptive in places; attempts a mechanism but it is partial; generally organized; conclusion present but may be generic; some errors, meaning still clear.
2 · DevelopingVague thesis that only partially addresses balance/change; uses only one source or misapplies evidence; mechanisms asserted but not explained; unclear organization and weak or missing conclusion; frequent errors that sometimes interfere with meaning.
1 · EmergingNo clear thesis, or does not address balance/change in a system; little or no source evidence; no meaningful explanation of any mechanism; minimal organization; frequent errors that interfere with understanding.
0 · No creditNo response, blank, or entirely off-topic.
Quick checklist while scoring: Does the thesis name a system maintaining balance or changing? Is there evidence from at least two of the four stimuli? Is at least one mechanism explained in detail, not just stated? Does the conclusion connect back to a general scientific principle? Grade reasoning and use of data first; treat spelling and grammar separately.