Science Reasoning Flashcards

A scientist hypothesizes that lack of sleep impairs memory consolidation. To test this, she has one group sleep normally and another stay awake all night, then tests both on a word-recall task. What assumption must be true for this experiment to be valid?

Answer: Both groups must be equivalent in memory ability before the experiment

If the groups differ in baseline memory ability, it would be impossible to attribute recall differences to sleep deprivation alone.

Hypothesis A: Increased CO₂ causes ocean acidification. Hypothesis B: Ocean acidification is caused by volcanic activity on the seafloor. A researcher finds that ocean pH correlates strongly with atmospheric CO₂ levels measured globally, not with proximity to undersea volcanoes. Which hypothesis does this support?

Answer: Hypothesis A only

Global correlation with atmospheric CO₂ rather than geographic correlation with volcanoes supports Hypothesis A.

A new drug lowers blood pressure in 70% of trial participants. Critics note the trial had no placebo group. Why is this criticism valid?

Answer: Without a placebo, the placebo effect cannot be separated from the drug's true effect

Without a placebo control, improvements may reflect expectation (placebo effect) rather than the drug's pharmacological action.

Which of the following best exemplifies the principle of falsifiability in science?

Answer: A hypothesis that predicts a specific outcome that experiments could disprove

Falsifiability requires that a hypothesis make specific, testable predictions that could be shown false by evidence.

Experiment results show that a new pesticide reduces pest damage by 40% but also reduces pollinator populations by 60%. Which statement reflects the most scientifically sound interpretation?

Answer: The benefit to crops must be weighed against the ecological cost to pollinators

Scientific interpretation requires evaluating all measured effects, including unintended ecological consequences.

A researcher tests whether vitamin C prevents colds. Of 500 subjects taking vitamin C, 80 got colds. Of 500 subjects taking a placebo, 100 got colds. The researcher concludes vitamin C 'completely prevents' colds. This conclusion is:

Answer: Overstated, because the data shows reduction in frequency, not complete prevention

80 colds still occurred in the vitamin C group, disproving 'complete prevention' — the data supports partial reduction only.

Two competing models predict how a glacier will retreat over 50 years. Model X predicts 10 km retreat; Model Y predicts 25 km retreat. After 25 years, the glacier has retreated 15 km. Which statement is best supported?

Answer: Current data is more consistent with Model Y's trajectory

At the halfway point, 15 km of retreat (vs. 5 km predicted by X and 12.5 km by Y) is closer to Model Y's rate.