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Practice Test 1 - High School Biology

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

  1. A cactus species lives in a desert where water is scarce. Long ago, ancestral plants in this lineage had larger leaves, but there was heritable variation in leaf size. Plants with smaller leaves lost less water and produced more seeds. Over many generations, the population evolved spines and thick water-storing stems. Which choice best explains why these traits are considered adaptations?
  2. A student records body temperature during a fever that breaks: - 0 min: 37.0°C - 30 min: 39.0°C - 45 min: sweating begins and skin blood vessels dilate - 75 min: 38.0°C - 120 min: 37.2°C Which choice best interprets the negative feedback shown by this time course?
  3. In a simplified model of tissue maintenance, a stem cell divides. One daughter cell stays a stem cell, and the other becomes a specialized cell for that tissue. What is the best reason this model helps explain long-term tissue health?
  4. A species of lizard produces offspring without mating, and the offspring are genetically identical to the mother (clones). Which description best fits this reproduction?
  5. A non-native plant is spreading through a grassland and reducing native wildflowers. Managers consider three actions: 1) Manual removal by volunteers each spring 2) Broad-spectrum herbicide sprayed across the grassland 3) Introducing an insect from the plant's native range that feeds on the invasive plant Which evaluation is most scientifically sound?
  6. A mutation occurs in a pigment gene and creates a new allele that can produce a new eye color in a population. Why is mutation considered the original source of all genetic variation? Context: Sexual reproduction can reshuffle existing alleles, but it does not create brand-new alleles by itself.
  7. Many seabirds nest in dense colonies on cliffs. Compared with nesting alone in widely separated locations, which advantage of colony living is most directly related to reproduction?
  8. A student compares DNA packaging to "thread wound onto spools." In this analogy, what do the "spools" represent?
  9. Which statement best describes the relationship among DNA, genes, and chromosomes?
  10. In a simple eye-color model, B represents a brown-eye allele (dominant) and b represents a blue-eye allele (recessive). Which pairing correctly matches genotype to phenotype?
  11. Two desert sites each have 4 lizard species. The counts are shown below. Site X: Species 1 (25), Species 2 (24), Species 3 (26), Species 4 (25) Site Y: Species 1 (90), Species 2 (4), Species 3 (3), Species 4 (3) Which statement is most accurate?
  12. A fossil called Tiktaalik has fish traits (fins and scales) and also limb-like bones and a neck that resemble early land vertebrates. Which statement best describes why this fossil is important evidence for evolution?
  13. Claim: A rabbit population evolved thicker fur in response to colder winters. Evidence collected: 1) In 2000, the average fur thickness of 100 rabbits was 12 mm; in 2020, the average was 13 mm. 2) In 2020, rabbits with thicker fur survived a severe cold snap at higher rates than rabbits with thinner fur. 3) A single rabbit kept in a colder cage grew slightly thicker fur within its lifetime. 4) Fur thickness is heritable: offspring fur thickness correlates with parent fur thickness in breeding records. Which choice best evaluates whether the evidence is sufficient to support the claim of evolution in this population?
  14. A model of tissue maintenance says: "Old cells die and are removed, and new cells appear that match the tissue." Which option best describes the missing cellular processes that create those matching replacement cells?
  15. In a meadow, producers store 30,000 kJ of energy. If primary consumers store 3,000 kJ and secondary consumers store 300 kJ, which conclusion best fits these data?
  16. A lake has 48,000 m² of suitable nesting shoreline for a species of turtle. Each turtle needs about 120 m² of shoreline territory to nest successfully. Estimate the carrying capacity KK for turtles based on shoreline space.
  17. Greenhouse gas emissions increase due to burning fossil fuels. Which option best models multiple pathways by which climate change can reduce biodiversity in both oceans and on land?
  18. Which sequence correctly describes the main steps of natural selection in a population?
  19. DNA can be compared to a cookbook: the entire DNA molecule contains many "recipes," and each recipe is a gene. In this analogy, what best corresponds to the words in a recipe that determine what it tells you to do?
  20. A student wants to model how the body responds on a hot day when sweating increases and skin looks flushed. Which model best connects the nervous and circulatory systems to these observable changes?

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