Pea seeds were allowed to germinate for 4 days and segments of the epicotyl around 1 cm were cut and placed in a nutrient solution having pH 7.0. These epicotyls were then treated with cyanide ( CN ⁻ ) at a concentration of 0.1 mM and the membrane potential was recorded. Cyanide was washed out and the membrane potential was further recorded up to 78 minutes. A graph of cell membrane potential ( mV ) against time (min