Caffeine on heart rate
· Use of Daphnia-
o Because they posses simple nervous system,
o Because they are see though so you can measure heart rate directly.
o Living organisms so you can treat them with respect and you put them back in the pond water
o Different gender, ages
o Different sizes
· Hard to count
o So fast inaccuracy
· Light from microscope
o Light and heat causes stress
· Acclimatized – take 2 reading and check the readings are the same before experiments.
· Random-counting heart rate with our eyes
· Systematic – something with the same degree of error for each result. Eg. Leaving the daphnia to acclimatize for five mins.
· Independent variable: caffeine conc. Min 5 conc. Of caffeine and control.
· Repeat exp. To improve reliability
· Risks: pond water wash with antibacterial soap your hands so that you…