Name: Vy Pham Instructor Lab: Gurneet Bola Shah
Class: BIOL Lab – S04 Date: October 14, 2020
The Effect of Chemicals on the Pulse Rate of Blackworms (Lumbriculus variegatus) Activity
The pulse rate of blackworms (Lumbriculus variegatus) increased as the concentration of
caffeine increased (Figure 1). The mean pulse rate of the control group (no caffeine) was lowest,
at 13.5 beats per minute ± 1.3 (95% C.I.). The mean pulse rate increased in the treatment group
#1 (low concentration of caffeine), at 16.2 beats per minute ± 1.6 (95% C.I.). The highest mean
pulse rate was 20.1 beats per minute ± 2.7 (95% C.I.), that was the pulse rate of the treatment
group #2 (high concentration of caffeine).
Figure 1. Mean pulse rate (beats per minutes) of blackworms (Lumbriculus variegatus) at no
caffeine (control), low concentration of caffeine and high concentration of caffeine. Error bars
represent 95% confidence intervals of the mean (n=10).
