Free ACT Science: Conflicting Viewpoints Questions and Answers 3 Flashcards

Hypothesis 1: Dinosaurs were cold-blooded like modern reptiles, relying on the environment for body heat. Hypothesis 2: Dinosaurs were warm-blooded like birds and mammals, generating internal heat. Fossilized bone tissue from large dinosaurs shows fibrolamellar bone (fast-growing bone found in warm-blooded animals). This evidence:

Answer: Supports Hypothesis 2, because fibrolamellar bone indicates rapid growth associated with warm-blooded metabolism

Fibrolamellar bone is associated with rapid, sustained growth requiring high metabolic rates — a characteristic of warm-blooded animals. This supports Hypothesis 2 that dinosaurs had warm-blooded metabolisms.

Researcher A argues that childhood exposure to diverse gut microbes builds immune resilience and reduces allergies (Hygiene Hypothesis). Researcher B argues allergies are primarily genetic. Which finding would best support Researcher A?

Answer: Children raised on farms with early exposure to animals and soil have significantly lower allergy rates than children raised in sterile urban environments

The farm/urban comparison isolates environmental (microbial exposure) from genetic factors. If farm children have lower allergies despite similar genetic diversity, this strongly supports the Hygiene Hypothesis (Researcher A).

Scientist 1: Increased atmospheric CO₂ is the primary driver of current global warming. Scientist 2: Natural solar cycle variations are the primary driver. Data shows that solar output has remained flat since 1980, while global temperatures have continued rising. This data:

Answer: Weakens Scientist 2's position by showing solar output and temperature are no longer correlated

If solar cycles drove temperature, temperature should correlate with solar output. Flat solar output with rising temperatures breaks that correlation — weakening Scientist 2's solar cycle hypothesis.

Model A: The appendix is a vestigial organ with no function. Model B: The appendix serves as a bacterial reservoir to repopulate gut flora after illness. Patients who have had appendectomies are significantly more likely to experience recurrent C. difficile intestinal infections. This finding:

Answer: Supports Model B, because without the appendix there is no reservoir to restore beneficial gut bacteria

Recurrent C. difficile infections after appendectomy suggest the appendix plays a role in gut flora recovery — consistent with the bacterial reservoir hypothesis (Model B).

Two nutritionists debate the primary cause of the obesity epidemic. Nutritionist 1: Excessive caloric intake (particularly from sugar) is the primary cause. Nutritionist 2: Sedentary lifestyle and inadequate physical activity are the primary cause. A population study finds that countries with high sugar consumption but high physical activity rates have low obesity rates. This evidence:

Answer: Supports Nutritionist 2, because physical activity appears to offset the effects of high sugar consumption

If high sugar consumption does not cause obesity when accompanied by high activity, this suggests activity level is the more critical variable — supporting Nutritionist 2's emphasis on physical activity.

Physicist 1 argues light is purely a wave (classical wave theory). Physicist 2 argues light behaves as both wave and particle (wave-particle duality). In the photoelectric effect, light of sufficient frequency ejects electrons from metal regardless of intensity, but low-frequency light of any intensity does not. This experiment:

Answer: Supports Physicist 2 — frequency-dependent ejection requires the particle (photon energy = hf) model; intensity alone (wave model) cannot explain this

The wave model predicts that higher intensity (more energy) should always eject electrons. The photoelectric effect shows frequency, not intensity, is decisive — requiring the photon (particle) model where each photon carries energy hf. This supports wave-particle duality (Physicist 2).