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Fill in the blanks

In the scenario below, fill in the blanks: A researcher tests whether drinking caffeinated coffee affects reaction time. Participants drink either caffeinated coffee or decaf, wait 15 minutes, then complete a reaction-time task on a computer.

The independent variable is ____.

The dependent variable is ____.

One good operational definition for reaction time is: ____.

Course
Introductory Biology Foundations: Cells, Genes, Evolution & Ecol
10 units46 lessons
Topics
Biology (introductory)Biochemistry (intro level)Cell & Molecular BiologyGeneticsEvolutionary BiologyEcology
About this course

Build a strong, integrated introduction to biology by learning core vocabulary and the cause–effect logic that connects biochemistry, cells, genes, evolution, and ecosystems. Focus on how science generates and tests explanations through hypotheses, experimental design (controls, independent/dependent variables), and evidence-based interpretation. Develop quantitative comfort with simple graphs, proportions, and frequency reasoning (including Hardy–Weinberg). Master key structure–function themes (macromolecules, enzymes, membranes, organelles), information flow (DNA→RNA→protein, mutations), energy transformations (ATP, respiration), inheritance (meiosis, Mendelian patterns), evolutionary mechanisms, and ecological energy flow and interactions.