Hypothesis and protocol

Hypothesis (if-then form):

If C. elegans are exposed to increasing concentrations of copper (the independent variable), then the percentage of worms still moving after 30 minutes (the dependent variable) will decrease, because copper is a toxic heavy metal that disrupts cell function.

Materials:

• Agar plates with synchronized adult C. elegans
• Copper sulfate stock solution and distilled water for dilutions
• Four concentrations (0 ppm control, 10 ppm, 50 ppm, 100 ppm)
• Micropipette and tips, dissecting microscope, timer, gloves

Procedure:

1. Label four plates: control (0 ppm), 10, 50, and 100 ppm.

2. Pipette the matching copper solution onto each treatment plate; add only distilled water to the control.

3. Transfer 10 worms to each plate.

4. At 0, 15, and 30 minutes, count and record how many worms are still moving.

5. Repeat the full run three times so results can be averaged.

Safety consideration:

Copper sulfate is an irritant, so I will wear gloves and goggles and dispose of all solutions in the labeled heavy-metal waste container. Rationale: this protects my skin and eyes and keeps the metal out of the regular sink and the environment.