[Campbell Biology P.562] In the Scientific Skills Exercise, the researchers investigated the... | Practice Question

In the Scientific Skills Exercise, the researchers investigated the relationship between 'Geographic Distance km ' and 'Reproductive Isolation Value' in dusky salamander populations. Which of the following best describes the roles of these variables in the study?

  • A: 'Geographic Distance' is the dependent variable, and 'Reproductive Isolation Value' is the independent variable.
  • B: 'Geographic Distance' is the independent variable, and 'Reproductive Isolation Value' is the dependent variable.
  • C: Both 'Geographic Distance' and 'Reproductive Isolation Value' are controlled variables.
  • D: Both 'Geographic Distance' and 'Reproductive Isolation Value' are experimental constants.

Explanation

The study aims to test the hypothesis that 'as distance between populations increases, so will their degree of reproductive isolation.' This implies that geographic distance is the variable that is manipulated or naturally varies independent variable , and reproductive isolation is the outcome that is measured dependent variable . The 'INTERPRET THE DATA' section confirms this by stating to 'Plot the independent variable on the x-axis and the dependent variable on the y-axis,' which for a relationship where y depends on x means x is independent and y is dependent.