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Practice Test 69 - High School Biology

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

  1. A human begins a long run after not eating for several hours. Muscle cells break down glycogen into glucose, which is then used to make ATP for muscle contraction. Why is glycogen synthesis important for muscle function?
  2. In a meadow ecosystem, a carbon atom starts in atmospheric CO2. It is taken up by grass, then the grass is eaten by a rabbit, and later the rabbit dies and is broken down by decomposers. Which statement best describes what happens to that carbon atom over time?
  3. A shallow cut damages the outer layer of skin. A student proposes four models for what must happen next for the cut to heal and restore normal skin function. Which model is most accurate?
  4. A carbon cycle model shows two arrows leaving the Plants box: - Plants → Animals (feeding) - Plants → Atmosphere (respiration) What do these two arrows indicate about carbon in plant biomass?
  5. A lizard population has heritable variation in heat tolerance. Over several decades, average summer temperatures rise and heat waves become more frequent. Which change is most likely to occur in the lizard population over generations?
  6. Blood contains several different types of cells (such as red blood cells and white blood cells) working together to transport materials and help defend the body. In this context, blood is best classified as which level of biological organization?
  7. A carbon cycle diagram shows these labeled arrows: [Atmosphere CO2] --(photosynthesis)--> [Plant biomass] [Plant biomass] --(feeding)--> [Animal biomass] [Animal biomass] --(respiration)--> [Atmosphere CO2] Which option correctly describes what happens to carbon during the arrow labeled "feeding"?
  8. A student learns that a series of whale fossils shows a progression from early land mammals with four legs to later forms with reduced hind limbs and more streamlined bodies, ending with modern whales that have tiny pelvic bones. DNA comparisons also show whales share more DNA similarities with hippos than with seals. Which option correctly identifies the types of evidence being used to support evolution and common ancestry?
  9. A conceptual diagram shows: Sunlight → chloroplast → glucose → starch (storage) Based on this model, what is the best interpretation of the arrow from glucose to starch?
  10. Which equation correctly represents cellular respiration at the whole-process level (overall inputs and outputs)?
  11. Blood glucose is regulated by two opposing hormones. After a meal, glucose rises above normal and insulin is released, lowering blood glucose. Hours later, if glucose falls below normal, glucagon is released, raising blood glucose. Together, levels usually stay within a narrow range around about 90 mg/dL. Which explanation best describes how these two negative feedback responses help maintain stability?
  12. Which choice is the best example of a tissue (a group of similar cells working together)?
  13. A food chain in a desert is: cactus (producer) → jackrabbit (primary consumer) → rattlesnake (secondary consumer) → hawk (tertiary consumer). Which is the best reason food chains typically have only about 4–5 trophic levels?
  14. A carbon atom is in a molecule of glucose in a plant leaf. A caterpillar eats the leaf, and later a bird eats the caterpillar. Which statement best describes what happens to that carbon atom as it moves through this food chain?
  15. A potato plant makes extra glucose during the day and links many glucose molecules together to form starch, storing it in tubers. In winter or at night when photosynthesis slows, the plant breaks starch back into glucose to power cellular respiration. How does starch synthesis connect to the plant's survival?
  16. Transcription is often described as the first step of gene expression (DNA → RNA → protein). Which statement best describes what happens to the DNA and RNA during transcription?
  17. During childbirth, uterine contractions begin. The contractions trigger signals that cause even stronger contractions, which then trigger even more strengthening, continuing until delivery. Which type of feedback mechanism is described?
  18. A teacher crosses two organisms with the same dominant phenotype and records the following offspring phenotypes: 75 show the dominant trait and 25 show the recessive trait. Which conclusion best matches the evidence?
  19. An island has several native bird species that are declining because an introduced rat species eats eggs and chicks. Conservationists consider three actions: (1) remove rats using traps and bait stations, (2) start a captive-breeding program for the birds, and (3) do nothing and let natural selection act. Which choice best explains the most effective first priority for preserving native bird biodiversity on the island?
  20. Cellular respiration is often compared to "burning" glucose, but it happens in controlled steps inside cells. Why is the stepwise breakdown important for ATP production?

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