Sally completed an investigation involving earthworms. She placed a worm on a moist paper towel and carefully marked the position of the worm on the paper towel. She placed a cardboard box over the worm and paper towel and left it undisturbed for 15 minutes. She removed the box and noted that the worm had not moved from its original position. She then took a flash light and shined it on the worm for 15 minutes. After the end of the 15 minutes she measured the distance the worm moved in cm.

Question

Sally completed an investigation involving earthworms. She placed a worm on a moist paper towel and carefully marked the position of the worm on the paper towel. She placed a cardboard box over the worm and paper towel and left it undisturbed for 15 minutes. She removed the box and noted that the worm had not moved from its original position. She then took a flash light and shined it on the worm for 15 minutes. After the end of the 15 minutes she measured the distance the worm moved in cm.

19. What is the independent variable?
20. What is the dependent variable?
21. What could Sally’s hypothesis have been?

Answer 1

19. The independent variable in Sally's investigation could be the amount of light the worm is exposed to.

20. The dependent variable in Sally's investigation could be the distance the worm moves.
21. Sally's hypothesis could have been that the amount of light exposure would directly affect how much the worm moves.

Answer 2

19. The independent variable in this investigation is the exposure of the worm to the flashlight.

20. The dependent variable in this investigation is the distance the worm moved after being exposed to the flashlight.

21. Sally's hypothesis could have been: "If I shine a flashlight on an earthworm, then it will move a greater distance than if it is not exposed to the light."