EFFECTS of CAFFEINE and ALCOHOL on Respiration

Problem: What are the effects of the drugs alcohol and caffeine on the respiration rate of Fathead Minnow?

You have probably observed that when people drink too much coffee, they are often hyperactive. They may be jittery, nervous, and complain about being unable to relax. On the other hand, when people drink too much alcohol their speech often slurs, they may lose control of their muscular coordination, and their reaction time slows down. Too much alcohol may even cause them to pass out. Since it is neither wise nor ethical for untrained scientists to experiment on humans, you will instead use a MODEL, in this case a Fathead Minnow, to test your hypotheses.


Minnow Respiration Lab with Sauk River Watershed District

1. Capture a living minnow from the stock jar and place it in a small jar.
2. To get the baseline respiration rate, count the number of gill cover movements for 15 seconds. The rate in a healthy minnow will be very rapid. Multiplying the beats counted in 15 seconds by 4 will give you the number of respirations per minute. Record your data on the table provided.
3. To test the effect of alcohol, place one pipette of 2% alcohol in the jar. Wait one minute and then count the respirations. Record your results on the provided table.
4. Using the same procedure, test the effects of 4% and 6% alcohol solutions. Record your results on the table provided.
5. After your series are done, return the minnow to the recovery tank.
6. Repeat the same procedure on a different minnow but use the caffeine solutions this time. Start with the lowest concentration and work your way up to the highest. Record your data on the table provided. Return your minnow to the recovery tank after completed.

Your goal is to get three alcohol series and three caffeine series done and recorded on the table in the allotted time. Answer the conclusion portion, and fully explain your ideas and answers to the questions on a separate piece of paper.