A line graph showing 'Daphnia Heart Rate and Caffeine' is plotted between 'Drops of Coffee Added' on x axis with ranges from 0 to 5 with an increment of 1 and 'Heart Rate (beats per minute)' on y axis with ranges from 0 (with break and continued from 120) to 190 with an increments of 10. The line passes through five points (0 comma 130), (1 comma 135), (2 comma 140), (3 comma 170) and (4 comma 180).