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Practice Test 3 - High School Biology

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

  1. A fertilizer spill entered a small lake in spring of Year 0. Scientists measured dissolved oxygen (DO) and the number of observed fish along a fixed shoreline transect. Table of measurements: - Pre-spill: DO 8.2 mg/L; fish count 120 - 1 month after spill: DO 2.1 mg/L; fish count 18 - Year 1: DO 5.6 mg/L; fish count 60 - Year 3: DO 7.4 mg/L; fish count 105 Which statement best describes the evidence for ecosystem change and recovery?
  2. Claim: Plants remove CO2_2 from the atmosphere during photosynthesis, helping carbon cycle between the atmosphere and living things. Observations from a school garden: 1) CO2_2 near leaves is lower at noon than at sunrise on sunny days. 2) CO2_2 near leaves is higher at night than at noon. 3) Plants grew taller during the month. 4) The soil felt moist after watering. Which observations are relevant evidence for the claim? (Choose the best answer.)
  3. A herd of musk oxen is approached by wolves. Adults move inward and form a tight circle facing outward, while calves remain in the center. The wolves have difficulty reaching the calves and eventually leave. What is the main advantage of this cooperative defense?
  4. In bone marrow, an unspecialized stem cell can become a red blood cell (oxygen transport), a white blood cell (immune defense), or a platelet (blood clotting). What is this process called, and what is the key idea behind it?
  5. Claim: In the carbon cycle, organisms return carbon to the atmosphere as CO2_2 through cellular respiration. Data from a sealed container experiment (same volume each time): 1) A container with only a small animal showed CO2_2 increasing from 420 ppm to 470 ppm in 1 hour. 2) A container with only a plant in bright light showed CO2_2 decreasing from 420 ppm to 395 ppm in 1 hour. 3) A container with a plant in darkness showed CO2_2 increasing from 420 ppm to 435 ppm in 1 hour. 4) The animal's fur is brown. Which evidence specifically supports the claim that respiration returns carbon to the atmosphere?
  6. During a 2-minute sprint, a student's breathing rate and heart rate both increase, and their leg muscles begin to feel tired. Which flowchart model best represents how respiratory, circulatory, and muscular systems interact to support the working muscles?
  7. A prairie contains many grass and wildflower species. During a drought, some plant species decline, but others tolerate dry conditions and continue growing. A nearby field planted with only one grass species turns mostly brown during the same drought. What best explains why the prairie's plant cover (overall plant population) stays more stable?
  8. A prairie was restored after heavy grazing stopped (Year 0). Scientists measured native plant species richness and the percent cover of bare ground. Data: - Year 0: Native species = 11; Bare ground = 55% - Year 2: Native species = 18; Bare ground = 38% - Year 5: Native species = 26; Bare ground = 22% - Year 10: Native species = 29; Bare ground = 20% - Reference prairie (never heavily grazed): Native species = 31; Bare ground = 18% Which statement best describes the restoration outcome by Year 10 compared with the reference prairie?​
  9. Put the following stages in the correct order, starting with the first stage of mitosis: prophase, metaphase, anaphase, telophase.​
  10. Two hydrangea bushes are cuttings from the same parent plant (same genotype). One is planted in acidic soil (pH 5.5) and produces blue flowers. The other is planted in alkaline soil (pH 7.5) and produces pink flowers. Which term best describes this situation?
  11. In a honeybee hive, some worker bees collect nectar, others feed larvae, and when a large animal disturbs the hive, many workers sting to defend it (even though stinging can kill the worker). Which choice best explains the benefit of this cooperative behavior?
  12. Claim: Social learning (learning from others) helps individuals gain a new foraging skill faster than learning alone. Evidence: 1) In a lab test, juveniles that watched a trained adult opened a puzzle feeder in an average of 3 days; juveniles tested alone took an average of 8 days. 2) In the same population, individuals with brighter fur had higher mating success. 3) In one anecdote, a single juvenile opened the feeder on the first day without watching anyone. Which piece of evidence is least relevant to evaluating the claim?
  13. During a 24-hour cycle, a plant photosynthesizes in daylight and performs cellular respiration day and night. Which model best represents what happens to matter (CO2, H2O, O2, glucose) and to energy over the full day?​
  14. Which sequence correctly shows the basic levels of DNA packaging from smallest to most condensed in a dividing human cell?
  15. Claim: Group living increases survival. Two studies are reported: - Study A (observational): In one valley, group-living animals had 78% survival and solitary animals had 60% survival, but group-living animals were mostly found near water while solitary animals were mostly found in drier areas. - Study B (experimental): Researchers randomly assigned animals to live alone or in groups in the same habitat area; survival was 80% in groups and 62% when alone. Which choice best compares the strength of evidence from the two studies for the claim?
  16. A student walks outside on a cold day and begins shivering. Their skin looks paler in the cold than it did indoors. Which model best represents how systems interact to respond to the temperature change?
  17. Atom accounting scenario: A plant cell starts with glucose molecules containing a total of 60 carbon atoms. After synthesis, the cell has built macromolecules that contain 60 carbon atoms total (some in starch, some in proteins, some in lipids). What does this best show about the carbon atoms during synthesis?
  18. A diploid organism has a cell with 2n chromosomes. After meiosis, what is the chromosome number in each resulting cell, and what is the main biological purpose of this reduction?
  19. DNA is sometimes compared to digital information storage. In this analogy, what is most like the "data" being stored?
  20. In the DNA double helix, where are the nitrogenous bases (A, T, G, C) located relative to the sugar-phosphate backbone?

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