Questions, Variables & Fair Investigations — Drills · Grade 7 Science
Chapter: Scientific Inquiry & Diversity of LifeWhat these drills covers
By the end of Questions, Variables & Fair Investigations you should be able to:
- I can explain questions, variables & fair investigations.
- I can use evidence, a model, and stated assumptions to support a biological explanation.
4 questions, multiple choice, numeric and written answer, each with a worked explanation.
Vocabulary used: testable question, independent variable, dependent variable, controlled variable, confound.
Problem 1
Which is the dependent variable in a water-and-growth test?
- Daily water amount
- Height change
- Container material
- Plant species
Answer and explanation
Height change
Height change is the measured response; daily water is the changed factor.
Problem 2
A seedling starts at 3 cm and ends at 8 cm. Find height change.
Answer and explanation
5 cm
Final minus initial: 8−3=5 cm.
Problem 3
Why does defining the outcome before testing help?
Answer and explanation
It keeps the comparison consistent and reduces the temptation to choose whichever observation later supports a favorite explanation.
Problem 4
Why should an unexpected trial remain in the record?
Answer and explanation
It may represent real variation or reveal a problem worth investigating. Removing it only because it disagrees with a prediction biases the evidence.