ADRENALINE AND DAPHNIA
Name: __________________
Class: __________________
Date: __________________
PRELAB QUESTIONS
1. Why would adrenaline act to increase heart rate and increase blood supply to the liver
and muscles?____________________________________________________________
_______________________________________________________________________
_______________________________________________________________________
2. What is the general purpose of the endocrine system? _________________________
_______________________________________________________________________
_______________________________________________________________________
3. Why are Daphnia convenient to study? _____________________________________
________________________________________________________________________
________________________________________________________________________
INVESTIGATION: OBSERVATIONS AND DATA
1. Daphnia Heart Rate
Normal
Time (in seconds) Required for
20 Beats
After Adrenaline
Trial 1
Trial 2
Trial 3
Average
Heart Rate (Beats per Minute)
2. Why are you asked to find the average time required for 20 heartbeats over three trials
instead of using the time from one trial only? _________________________________
_______________________________________________________________________
_______________________________________________________________________
_______________________________________________________________________
3. To calculate the daphnia heartbeat rate in beats per minute, use the following formula:
20 beats
average time (sec) for 20 beats
X
60 seconds
1 minute
=
number of beats
1 minute
Calculations:
4. Calculate the Daphnia heartbeat rate after application of adrenaline, using the formula
in item 3.
Calculations:
5. Based on your observations, what effect does adrenaline have on the heart rate of
Daphnia? _______________________________________________________________
________________________________________________________________________
________________________________________________________________________
6. Based on your data, what is the difference between a Daphnia’s normal heart rate and
its heart rate after exposure to adrenaline solution? ______________________________
________________________________________________________________________
________________________________________________________________________
7. How does adrenaline prepare Daphnia for an emergency? ___________________
________________________________________________________________________
________________________________________________________________________
ANALYSIS AND CONCLUSIONS
1. Why is the body’s response to adrenaline called a “fight or flight” response? _______
________________________________________________________________________
________________________________________________________________________