Practice Test 27 - High School Biology

20 questions. Answer them in any order, then submit to see your score and every explanation.

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1. A sealed bottle ecosystem contains an aquatic plant and a small shrimp. The bottle is sealed (no gas exchange with outside air). The teacher turns off the light for several days. Which model best explains what happens in terms of matter cycling and energy flow through photosynthesis and cellular respiration?
2. A line graph (described below) shows the frequency of a heat-tolerance allele $H$ in a rabbit population over time. A major heat wave began in Year 6. Data points: Year 0 = 0.12, Year 3 = 0.11, Year 6 = 0.12, Year 9 = 0.26, Year 12 = 0.44, Year 15 = 0.60 Which statement best connects the pattern in the data to a likely evolutionary mechanism?
3. A fishery targets a species whose population is declining from overharvesting. Two proposed strategies are: Strategy 1—set and enforce catch limits based on population monitoring (sustainable harvesting). Strategy 2—increase the number of fishing boats to spread the catch among more people. Which evaluation is most accurate?
4. A student scrapes their knee. Over the next week, the wound closes and the skin surface looks normal again. Which model best explains how the body repairs the damaged skin using cell division and differentiation?
5. A small cut damages a blood vessel. Platelets stick to the damaged area and release chemicals that attract more platelets. As more platelets arrive, they release more chemicals, which attracts even more platelets. The process speeds up until a clot forms and the bleeding stops. Which option best describes how this feedback loop works?
6. Vertebrate embryos (fish, chicken, and human) look very similar early in development, showing features such as tails and pharyngeal pouches. Later in development they become more different. Which type of evidence for evolution does this best represent, and what does it suggest?
7. A diagram in a textbook shows the sequence: DNA double helix → DNA wrapped around histone proteins (like thread around spools) → further coiling/folding → a condensed structure visible during cell division. What is the final condensed structure called?
8. In a lizard species, spotted skin (A) is dominant over plain skin (a). Two heterozygous lizards are crossed: $Aa \times Aa$. Each offspring is an independent event. If the first offspring is plain (aa), what is the probability that the second offspring will also be plain (aa)?
9. Claim: Living in groups increases survival because individuals can detect predators sooner. Evidence from a field study of the same species in the same habitat over one season: - Group-living individuals (groups of 8–12): 82 out of 100 survived. - Solitary individuals: 54 out of 100 survived. - Average time to detect a model predator: groups detected it in 12 seconds; solitary individuals detected it in 28 seconds. Which choice best evaluates whether the evidence supports the claim?
10. A room thermostat is set to 20°C. When the room cools to 18°C, the thermostat detects the change and turns the heater on. The room warms to 20°C and the heater turns off. Which choice best connects this example to how negative feedback maintains homeostasis in organisms?
11. In a finch population, beak size is a heritable trait: some birds have small beaks and some have large beaks. A drought reduces the number of small, soft seeds, leaving mostly large, tough seeds. Birds with large beaks are more likely to survive and produce offspring. After many generations, what change is most likely in the finch population?
12. A DNA template strand contains the sequence ATGC. What RNA sequence would be produced during transcription (complementary to the template, using U instead of T)?
13. Claim: Energy flows one-way through ecosystems (it does not cycle) because energy is lost as heat at each trophic level. Evidence from a pond food web study: 1) Producers store about 10,000 kJ of chemical energy. 2) Herbivores store about 1,200 kJ of chemical energy. 3) Carnivores store about 120 kJ of chemical energy. 4) When organisms are active, the surrounding water temperature increases slightly. 5) Many pond plants are green. Which evidence is relevant and supports the claim about one-way energy flow? (Select the best option.)
14. Two students propose models for urban development impacts on a wetland. Model 1: [Urban development] → [Wetland drained/filled] → [Habitat loss] → [Population declines] → [Reduced biodiversity] Model 2: [Urban development] → [Reduced biodiversity] Which statement best compares these models?
15. A lizard population has heritable variation in leg length. A new predator is introduced, and lizards that can run faster are less likely to be caught. After many generations, the population has longer average leg length. Which statement best describes what natural selection acts on and what changes over time?
16. A student makes a diagram to explain why they breathe faster during exercise. Their diagram includes three boxes: Respiratory system, Circulatory system, and Muscular system. Which set of labeled arrows is most important to include to show the key material flows among these systems during exercise?
17. A strawberry plant can make seeds after pollination, and it can also spread by sending out runners that grow into new plants. Which statement correctly compares these two reproduction methods?
18. A student claims that a population is evolving whenever it grows in size. A scientist tracked a mouse population size and the frequency of allele $T$ over 5 years. Year 1: population size 120, $T$ = 0.41 Year 2: population size 180, $T$ = 0.40 Year 3: population size 260, $T$ = 0.41 Year 4: population size 310, $T$ = 0.40 Year 5: population size 500, $T$ = 0.41 Which statement best evaluates the student's claim using the data?
19. A bowl of unripe fruit contains one ripe banana. The ripe banana releases a gas that causes nearby fruit to ripen faster. As more fruit ripens, even more of the gas is released, speeding up ripening in the whole bowl. Which type of feedback is described?
20. In a mouse population, allele $D$ helps digest a new food source. Mice with $DD$ or $Dd$ leave an average of 6 offspring each, while $dd$ mice leave an average of 2 offspring each. Without doing exact calculations, what is the most likely long-term trend?

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