First, there is a need to understand what dependent, independent, and constant variables are.
- Dependent variable is 'effect' variable, the actual variable to be measured in the course of experiments. Its value depends on another variable that is supplied.
- Independent variable is the 'cause' variable an is supplied by researchers in varied values. Its value affects another variable, the dependent variable.
- Constant variables are all other variables in experiments that are neither dependent nor independent and are not manipulated in any form throughout the experiment.
Thus, in the case of Mr. Spock:
- Dependent variable - intelligence
- Independent variable - mind melds
- Constant variable - not stated
On weightlessness and tomato:
- Dependent variable: growth rate
- Independent variable - weightlessness
- Constant - not stated
More on experimental variables can be found here: https://brainly.com/question/6350073
