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Interpret experiments and evaluate conflicting scientific viewpoints.
Learn step-by-step with practice exercises built right in.
40 questions, 35 minutes. Seven passages:
ACT Tip: The ACT Science section tests reading and interpretation more than science knowledge.
Students tested how temperature affects plant growth. They grew plants at 15°C, 20°C, and 25°C and measured height after 2 weeks. What is the independent variable?
Solution:
Independent variable = what the experimenter changes
In this experiment:
Answer: Temperature
ACT Tip: Independent comes FIRST (cause), dependent comes SECOND (effect)
Why would researchers perform an experiment 3 times instead of just once?
Solution:
Multiple trials serve several purposes:
Answer: To increase reliability and reduce the impact of random error
ACT Tip: More trials = more reliable data!
An experiment tested 3 fertilizers (A, B, C) on tomato plants. All plants received the same amount of water and sunlight. What is the purpose of keeping water and sunlight constant?
Solution:
These are control variables (kept constant).
Purpose:
This is called a "controlled experiment"
Answer: To ensure that any differences in plant growth are due to the fertilizer type and not other factors
Control variables eliminate confounding factors!