Laura Chipperfield
CORE PRACTICAL
Does caffeine affect heart rate?
Method
- Use a pipette to transfer a daphnia to a cavity slide. Remove the water around the daphnia using filter paper. Add one or two drops of distilled water
- Look at the daphnia through a microscope. Use a stopwatch to record the number of heartbeats per minute. Record the heart rate at intervals of two minutes over a 10-minute period.
- Repeat the procedure using other daphnia in fresh slide and cover slips. Replace the water with caffeine solution. Repeat the procedure using several different concentrations of caffeine.
Results