Mammalian Dive Response Lab Name:__________________ Hr:____ The dive response is characterized by three major physiological responses: apnea, bradycardia and peripheral vasoconstriction. Define each one and explain what role each response plays in maintaining homeostasis as these animals dive. The majority of the research on the diving response has been done on seals. The Weddell seal of Antarctica is a great example. Weddell seals can hold their breath for extended periods of 20 minutes to an hour and can dive to depths of 500 meters. A much smaller version of the dive response occurs in all mammals and is easy to observe in humans. When cold water contacts the face or inside of the nose, the brain responds by inhibiting breathing and decreasing heart rate. In this experiment, you will investigate the diving reflex. Safety If you have any kind of breathing difficulties, please observe but do not participate in contributing data. Definition in your own words How it helps marine mammals maintain homeostasis Apnea Bradycardia Peripheral vasoconstriction Looking at the effects of the dive response, how could data be collected in class today for each of the variables? 1. Apnea: 2. Bradycardia: 3. Vasoconstriction: Sea otter diving behavior Blue whales are the largest animals on Earth and can dive to great depths when foraging. Sea otters, as the smallest marine mammal, do not need to forage deep for the small mollusks, urchins, and crustaceans they consume. 4. Observe the graph at the right and describe the trend you see. 1 5. Identify conditions that diving mammals like the sea otter might encounter that could initiate the dive response. 6. What scientific question will our data help answer? 7. Read the procedure. Write three (3) things that can be done in this lab to avoid inaccurate data. Basic Protocol for All Tests: 1. No individual should perform this task if they have any kind of medical issue that would increase risk to their health. 2. All test subjects should lean over the lab table with elbows resting on their lap or on the table surface and their head down over the water. 3. At the beginning of each trial, have the subject take a deep (but not maximum) breath and hold it for up to 30 seconds during trials. 4. Subjects should not hyperventilate before holding their breath. Dive response procedure 1. Remind the volunteer to sit in testing posture with their hands in their lap or resting on the table. 2. Each group member should contribute to the data collection process. Record the name of the group member responsible for each task: Test subject (VOLUNTEER) Timer Measure heart rate Measure breathing rate (number of breaths) 3. Control: The test subject should breathe normally for a designated time. Measure and record subjects' heart rate and breathing rate. 4. Apnea (no dive): Have the test subject hold their breath. They can stop when they feel uncomfortable or at 30 seconds; whichever comes first. Measure and record the subject’s heart rate while holding their breath. Record in Apnea (No Dive) column. 5. Apnea (dive): Have the test subject hold their breath for no longer than 30 seconds while submerging their face in water. Measure and record the subject’s heart rate. Record this data in the Apnea (Dive) column. 2 6. Recovery from dive: Allow the test subject to recover from the dive for 30 seconds. Measure and record the subject’s heart rate and breathing rate. Record this data in the Recovery from Dive column. 7. Repeat so your group has three trials of this procedure. Data Table Graph the mean data above so you can more easily compare the different responses. Be sure to include both breathing and heart rates in the same graph (both y-axis) to see if any trends emerge. Be sure to include all labels and titles on this graph. 3 Experiment extension Select one question to investigate: ● Where on the face are the sensors that stimulate the dive reflex (how much of the face needs to be under water?) ● Does the dive response vary based on water temperature? ● Does fitness level affect the dive response (compare data of people who are regularly active vs. those that are not)? ● Does the size of the breath affect the dive response? ● Are there any psychological factors that could affect the dive response? 8. Summarize how you will collect necessary for your selected experiment. 9. What must stay constant during this investigation in order to have accurate data? 10. Discuss your experiment with Mrs. McDermid before you proceed. McD initials: ___________ 11. Carry out your experiment and collect your data in an organized way. Breathing rate Trial 1 Trial 2 Trial 3 Heart rate Trial 1 Trial 2 Trial 3 4 Analysis: Make sure to support all answers with evidence and reasoning when appropriate. 1) What happens to the heart rate while holding one’s breath? 2) How did the subject’s resting heart rate compare to their heart rate while they were holding their breath? 3) What happens to the subject’s heart rate as their face is submerged in the water? 4) What caused the subject’s heart rate to change when their face was submerged in water? 5) How would the mammalian diving reflex help a person who falls into cold water? Think in terms of the organs that need oxygen. Drawing Conclusions: 1) Identify any patterns that you can see in your data to support or refute your hypothesis. 2) Evaluate the significance of your data. What are the conclusions that you can draw from your data? 3) Evaluate the limitations of your data. What conclusions can you draw from your data? 5 Extension experiment 1) What did you learn from your extension experiment: what claim can be made? 2) List specific data comparisons that helped you determine that claim ● ● ● 3) Does your data make sense? What science concepts can help explain your results? 6 Rubric - Human Dive Response Lab A - Mastery D A T A C - Basic D/F - Minimal Breathing rate data is accurate and appropriate (including units). Breathing rate data is appropriate but may have 1 misconception present. Breathing rate data is appropriate but may have 2 misconceptions present. Breathing rate data is not accurate and/or appropriate. Multiple misconceptions present. Heart rate data is accurate and appropriate (including units). Heart rate data is appropriate but may have 1 misconception present. Heart rate data is appropriate but may have 2 misconceptions present. Heart rate data is not accurate and/or appropriate. Multiple misconceptions present. All necessary components of the graph are labeled and appropriate. All necessary components of the graph are labeled and appropriate but may have 1 misconception. Most necessary components of the graph are labeled and appropriate but may have 2 misconceptions. Data trends are accurate and appropriate for the graph but may have 1 misconception. Data trends are appropriate for the graph but may have 2 misconceptions. Necessary components of the graph are not labeled and/or inappropriate. X-Axis Y-Axis Y-Axis 2 Units Title Key All data analysis questions have an accurate and appropriate response but may have 1 misconception. All data analysis questions have an appropriate response but may have 2 misconceptions. . Student responses clearly demonstrate understanding of scientific concepts and relationships between variables but may have 1 misconception. Student responses demonstrate understanding of scientific concepts and/or relationships between variables but may have 2 misconceptions. Data trends are accurate and appropriate for the graph. All data analysis questions have an accurate and appropriate response. Student responses clearly demonstrate understanding of scientific concepts and relationships between variables. I N V E S T I G A T I O N B - Proficient Data trends are not accurate and/or in appropriate for the graph. Data analysis questions do not have an accurate and/or appropriate response. Student responses clearly do not demonstrate understanding of scientific concepts and relationships between variables. Multiple minor and/or major misconceptions present. 1-5 pre-lab question responses are accurate and appropriate for the lab. 1-5 pre-lab question responses are accurate and appropriate for the lab but may have 1 misconception. 1-5 pre-lab question responses are appropriate for the lab but may have 2 misconceptions. 1-5 Pre-lab question responses are not accurate and/or inappropriate for the lab. Multiple misconceptions are evident. 6 Student has developed a scientific question that is testable.. 6 Student has developed a scientific question that is testable but may have 1 misconception. 6 Student has developed a question to test but it is not scientific. 6 Student question is irrelevant to task at hand and/or has multiple misconceptions. 7 Explanation provided outlines possible sources of error, what will be done to minimize error and demonstrates multiple trials for the experiment but may have 1 misconception. 7 Explanation provided outlines possible sources of error, what will be done to minimize error and demonstrates multiple trials for the experiment but may have 2 misconceptions. 7 Explanation does not provide an outline of possible sources of error, what will be done to minimize error and demonstrates multiple trials for the experiment. Major misconceptions present. Experiment designed but explanation does not clearly show it is a controlled experiment Experimental design is present but is lacking details/unclear/difficult to understand. 7 Explanation provided outlines possible sources of error, what will be done to minimize error and demonstrates multiple trials for the experiment. Student has clearly communicated a controlled experiment to test one of the scientific questions Data is appropriately analyzed Experimental design is inaccurate and/or inappropriate. Data is provided and mostly supports the claim 7