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Practice Test 75 - High School Biology

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

  1. A cell performs aerobic cellular respiration: C6H12O6+6O2→6CO2+6H2O+ATP (energy)\mathrm{C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + ATP\ (energy)}. Which statement best describes what happens to the atoms during the reaction?
  2. A lake is contaminated by mercury from historical industrial discharge. A proposal suggests adding a chemical that binds mercury so it sinks into sediments. Which is the best scientific concern when evaluating this proposal for long-term ecosystem health?
  3. A lab grows bacteria in a flask. The nutrient supply available each day is 900 mg, and each bacterium requires 3 mg of nutrient per day to survive and divide. Using K=total nutrient per daynutrient needed per bacterium per dayK = \frac{\text{total nutrient per day}}{\text{nutrient needed per bacterium per day}}, what is the carrying capacity (K) in bacteria per day (based on nutrients)?
  4. Which statement best distinguishes ecosystem stability from ecosystem resilience?
  5. Many seabirds nest in dense colonies on cliffs. Although crowding can increase competition for space and spread disease, colonies are still common. Which advantage best helps explain why nesting in a colony can be beneficial?
  6. Claim: Carbon matter cycles through an ecosystem (carbon atoms move between the air, organisms, and the soil). Evidence collected by a student group: 1) CO2_2 concentration near a patch of grass drops from 415 ppm at 8 a.m. to 395 ppm at 2 p.m. on a sunny day. 2) CO2_2 concentration near the same grass rises from 398 ppm at 8 p.m. to 420 ppm at 4 a.m. 3) A container of moist leaf litter kept at room temperature releases CO2_2 over 24 hours, while an identical container of sterilized (microbe-killed) leaf litter releases much less CO2_2. 4) The grass in the patch is green. Which set of evidence is most relevant and sufficient to support the claim?
  7. Claim: Two separated populations of the same frog species are diverging (evolving differences) after being isolated by a new highway for 25 years. Evidence: 1) Population North: allele A frequency = 0.70; Population South: allele A frequency = 0.35 (measured in 2025). 2) In 2000 (before the highway), allele A frequency across the whole area was 0.55. 3) In 2025, average body mass differs: North = 18 g, South = 18 g. 4) A researcher notes that one frog learned to avoid cars by jumping later at night. Which evaluation best supports the claim of population divergence using relevant evidence?
  8. A student gets a small cut on their finger while cooking. Over the next day, the area becomes red and slightly swollen as the body responds. Which model best represents how systems interact to respond to the injury?
  9. Which example is best classified at the cell level of organization?
  10. In rabbits, black fur (B) is dominant to white fur (b). A black rabbit is crossed with another black rabbit. Their offspring include both black and white rabbits. Which Punnett-square-based claim is supported?
  11. A student runs up stairs and their body temperature rises above its normal set point. In response, sweating increases, which cools the body and brings temperature back down toward normal. Which type of feedback loop is described?
  12. A single gene controls earlobe type: free earlobes (E) are dominant to attached earlobes (e). Two parents both have free earlobes, but one of their children has attached earlobes. What does this evidence best support?
  13. A pride of lions hunts zebra. Two lions stalk from downwind while another lion waits near a common escape route. When the zebra bolts, the waiting lion charges and the others join to bring it down. Compared with a lone lion hunting zebra, what is the best explanation for why the pride's strategy can increase success?
  14. In a forest, oak trees use sunlight, CO2, and water to make sugars. Deer eat oak leaves, and wolves eat deer. Mushrooms grow on fallen logs and break them down. Which statement best distinguishes producers from consumers in this ecosystem?
  15. Which event happens during cytokinesis (not during the nuclear division stages of mitosis)?
  16. A disease hits two populations of the same crop. Population 1 is genetically diverse (many different genetic types). Population 2 is genetically uniform (nearly identical plants). Both are exposed to the same pathogen. Which statement best links biodiversity (genetic diversity) to population stability?
  17. A plant is placed in a sunny window but is not watered for several days. Based on the overall photosynthesis process, which required input is missing, causing photosynthesis to slow or stop?
  18. A student measures leaf length (cm) from 10 plants in the same population: 3.2, 3.5, 3.7, 3.9, 4.0, 4.1, 4.4, 4.6, 4.8, 5.0 What is the range of leaf length in this sample?
  19. A herd of deer lives in a forest preserve. During spring and summer, grasses and shrubs are abundant and the deer population increases. After several years, the population stops increasing and stays around 180 deer. Rangers notice that each winter many deer are underweight and fewer fawns are born the following spring, even though water and space are still available. Which factor is most likely limiting the deer population size (carrying capacity, KK) in this preserve?
  20. A DNA segment changes from ATGCCG to ATGCTG (one base is different). Conceptually, what is the most accurate statement about this change?

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