Dr. Bruce W. Grant and Dr. Itzick Vatnick
Department of Biology, Widener University
Chester, PA, 19013, BWG office Loveland #9/ x4017, IV office K516/ x4245
grant@pop1.science.widener.edu and vatnick@pop1.science.widener.edu
This page was last modified 29 September 2003, and has been accessed times since 1 January 2003.
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Your Answers to Question 1:
Q1 | Question 1. Examine the excel spreadsheet sheet containing your log log plots of body mass and metabolism (MetabolismLab1StudentResults.xls): (a) What are the slopes of the best fit lines? (b) How can these slopes be used in metabolic investagations? (c) Describe the effect of body mass on metabolic rate? [#1] |
Q1-A | see.... |
Q1-B | see.... |
Q1-C | (a) The slopes of these lines describe the relationship that exists between the variables. Positive slopes indicate a positive relationship where the increase in one variable is followed by an increase in the other. A negative slope indicates a negative relationship between variable where the increase in one causes a decrease in the other. (b) The information contained in these slopes can be used to possibly predict the expected oxygen consumption or metabolic rate for animals of various sizes. (c) As body mass increases, the total oxygen consumption for the animal increased but the specific oxygen consumption (rate of O2 consumption per unit body mass) decreased with increased body size and mass. |
Q1-D | (a) -.03 (b) From the slope it can be shown that the metabolic rate decreases as the temperature of the environment that the organisms are tested in increases. We can use do more metabolic investigations and compare the slopes of those lines to the slope of the previous experiment. (c) As body mass increases in an individual the metabolic rate also increases. |
Q1-E | see... |
Q1-F | (a) These slopes tell us the relationship between body mass and metabolic rate along with the relationship between specific rate and body mass. (b) We can compare this data to real organisms and see if with body mass the oxygen consumption truly goes down. They can also help us to predict in made up situations. (c) When body mass goes up the metabolic rate goes down, also when the body mass goes up the specific rate goes down. |
Q1-G | (a) the slope of these lines determines the rate at which an organism is consuming oxygen per unit body mass. According to the authors of our book, Animal Physiology Adaptation and Environment, oxygen consumption rates tend to produce a slope of .75 and a slope of 1.0 means that the organism is consuming oxygen at a rate directly proportional to its body mass. (b) see... (c) see... |
Q1-H | (a) the slope of these lines determines the rate at which an organism is consuming oxygen per unit body mass. According to the authors of our book, Animal Physiology Adaptation and Environment, oxygen consumption rates tend to produce a slope of .75 and a slope of 1.0 means that the organism is consuming oxygen at a rate directly proportional to its body mass. (b)Considering that the slopes are the change in metabolism as body size varies, the slopes can be used in future investigations as representatives. They could represent how results are likely to look, perhaps is there is an investigation about the relationship between metabolic rate and body size. The graphs are a sort of standard to match experimental results to. (c) As far as total oxygen consumption is concerned the bigger the size of the animal (bigger the body mass) the greater the O2 consumption. However, when comparing the rates of specific oxygen consumption, which is the rate of oxygen consumption per unit body mass, the rate actually decreases continuously with the increase in body mass. An example would be the elephant that has a very large body mass, and a very large total O2 consumption. However, his specific metabolic rate is quite low (0.07). |
Q1-I | see ... |
Q1-J | see... |
Q1-K | (a) 0.7104 for log O2 / log of mass -.2902 for log O2 consumption / kg vs log of mass (b) The first graph shows Oxygen Consumption is proportionally related to metabolic rate. The more metabolically active an animal is the more O2 it consumes. The second graph shows an inverse proportionality between Mass of animal and O2 consumption per gram. The bigger the animal the less O2 per gram it uses. (c) The regression line shows the oxygen consumption in mammals per unit of body mass decreases regularly with increasing body size. (The bigger the animal is, the less O2 consumption per gram.) ALSO (The bigger the animal is the more O2 is consumed.) The slope represents a linear relationship quantitatively. |
Q1-L | see... (b) Considering that the slopes are the amount of change in metabolism as the body size varies, the slopes of the graphs can be used in future investigations as representatives. They can show a rough appearance of how results are likely to look like if there is a similar situation. To sum it all up, the graphs can serve as a sort of standard to match results from future experiments to. see... |
Q1-M | See ... |
Q1-N | (a) The slope of the line representing the log of body mass vs. log oxygen consumption is .7044. (b) We can use this slope in determining the relationship between body mass and metabolism. Since the slope is positive, we know that as body mass increases, the volume of oxygen consumed increases as well. (c) As body mass increases, oxygen consumption goes up and the specific rate goes down. |
Q1-O | (a) The slope of the best fit lines represents the idea that oxygen consumption of mammals per unit body size decreases as the body size increases. (b) As we did today in lab, the oxygen out put of the animal can be measured in ml/sec. That data can then be plotted against the mass of the animal. This can be used in scientific investigations to compare various animal (or species) metabolisms. (c) The metabolic rate increases as the body size of the animal decreases. The textbook states that data relating body size to oxygen consumption have been recorded for all different types of animals (vertebrate and invertebrate). |
Your Answers to Question 2:
Q2 | Question 2. What were three of the main ideas, general concepts, or principles that you were supposed to understand and take with you from the lab: "Metabolism of Ectotherms and Endotherms"? [#2] |
Q2-A | 1 - Animals acquire energy from either fats, carbohydrates, or proteins. The most energy comes from fats. If comparing energy per liter of oxygen, then the energy is the same for all three. 2 - A change in the body mass of the animal changes the oxygen consumption; therefore, there is a relationship between body mass and oxygen consumption. 3 - As body mass is increased, weight specific oxygen consumption decreases. |
Q2-B | 1 - A change in body mass causes a change in the oxygen consumption. 2 - As the body mass increases, the specific metabolic rate decreases, and the total metabolic rate increases. 3 - it takes more oxygen to liberate heat from fats then carbohydrates and proteins. |
Q2-C | 1 - Energy only comes from 3 sources-carbohydrates, fat and protein 2 - Energy yield per liter of O2 is approximately the same for CHO, fats and protein 3 - As body mass increases, total O2 consumption increases but specific O2 consumption decreases. |
Q2-D | 1 - Factors that affect metabolic rate include body mass, temperature of the environment, and temperature the individual is acclimated to. 2 - Endotherms have a higher metabolic rate than ectotherms. 3 - Endotherms have a higher metabolic rate at cooler temperatures because their bodies work hard to maintain the high internal temperature. At extreme hot temperatures endotherms work equally as hard to maintain their body temperature and not get to hot. |
Q2-E | 1 - Endotherms spend more energy on maintaining body temperature than do ectotherms 2 - The metabolic rate of an organism can be measured from the oxygen consumption. 3 - oxygen consumption per unit body mass increases with decreasing body size. |
Q2-F | 1 â€" Endotherms consume oxygen faster than ectoderms 2 â€" Endotherms consume oxygen faster at low temperatures 3 â€" A fast metabolic rate is a very energy consuming trait. |
Q2-G | 1 - To determine and understand the difference in oxygen consumption between endotherms and ectotherms 2 - To understand how body mass affects an organism's oxygen consumption 3 - To understand the difference between specific and total oxygen consumption and be able to plot these value on a semi-log and log log function graph in excel and evaluate the slopes. |
Q2-H | 1 - That one way of estimating your metabolic rate is by measuring your total oxygen consumption and your body mass 2 - the difference between total oxygen consumption and specific oxygen consumption (specific metabolic rate) and how to correctly plot both of these 3 - To compare the metabolic rates of an ectotherm and an endotherm, take notice of these differences and understand why they are different. |
Q2-I | 1 - the relationships between body mass and oxygen consumption 2 - differences in metabolic rate of ecto and endos 3 - energy allocation basis of such |
Q2-J | 1 - Ectotherms have a lower metabolic rate then endotherms. 2 - Measuring oxygen consumption is one way to calculate metabolic rate. Other ways to calculate metabolic rate include calculating the difference between the energy value of al food intake and the amount of energy of all excretions and by finding total heat production of an organism using a calorimeter. 3 - The reason that oxygen can be used, as a practical measure of metabolic rate is that the amount of heat produced for each liter of oxygen used in metabolism remains nearly constant, irrespective of whether fats, carbohydrates or proteins are oxidized. |
Q2-K | 1 - Endotherms have a higher metabolic rate than ectotherms 2 - Metabolism is about glycolysis 3 - The correlations between CO2 O2 and metabolic rate |
Q2-L | 1 - Endotherms have a higher metabolic rate than ectotherms. 2 - As the weight of an endotherm/mammal goes up, it's metabolic rate goes down. 3 - Endotherms that are kept in colder environments have a slower metabolic rate than those that are in warmer temperatures. |
Q2-M | 1 - Organisms obtain their energy from three sources- fats, proteins and carbohydrates. 2 - An organism's size affects its metabolic rate. For example, a large organism will consume more oxygen than a smaller organism, but a smaller organism will consume more oxygen per gram than a larger organism. 3 - The metabolic rate of an organism can be calculated using oxygen consumption because the amount of heat released from each liter of oxygen consumed is almost equal regardless of the food source- protein, fat or carbohydrate. |
Q2-N | 1 - the effect of various factors on metabolic rate i.e. temperature, mass 2 - how oxygen consumption relates to the metabolic rate 3 - how can one measure oxygen consumption as a function of metabolic rate |
Q2-O | 1 - to understand that body mass is the independent variable, when there is an increase or decrease in body mass this influences the oxygen consumption2 - to learn how to calculate the specific oxygen consumption 3 - to see the relationship between body size and specific oxygen consumption |
Your Answers to Question 3:
Q3 | Question 3. What was the one thing you learned from this lab that you will likely remember a year from now? [#3] |
Q3-A | I will remember that cold acclimatized frogs move less frequently than warm acclimatized frogs; therefore, it is much easier to transport the cold acclimatized frogs. |
Q3-B | Temperature has a great effect on the movement and activity of an animal. Example: the frogs that were in the refrigerator barely moved or they moved at a slower rate then the frogs that were kept at room temperature. The room temperature frogs were tough to handle because they moved quickly. |
Q3-C | I will remember the distinction between total O2 consumption and the specific O2 consumption rates. The difference was mad very clear during this lab activity. |
Q3-D | I will remember that no experiment is void of problems. Also, that the quality of the equipment could save or cost the individuals carrying out the experiment a lot of time and accuracy. |
Q3-E | Endotherms use up a lot of energy trying to maintain their body temperature, while ectoderms do not require a lot. |
Q3-F | How to experimentally determine how much oxygen an organism consumes. |
Q3-G | I will definitely remember how hard it is to cram three lizards into a metabolic rate chamber. I will also remember how to find out an organisms metabolic rate, by determining oxygen consumption. Previous to this lab I really did not know how easy it was to determine metabolic rate through oxygen consumption (a crude determination anyway). In fact, I really wasn't fully aware of the variables which affect metabolism or especially that oxygen consumption was an indicator of metabolic rate. |
Q3-H | I truly felt bad for the animals while they were in the sealed containers, and being subjected to such a caustic material (sodalime). Therefore, I think that if I ever had to measure oxygen consumption again (a year from now or even later) I would use a different procedure. |
Q3-I | metabolic rate and oxygen consumption are used in terhanably but really measuring oxygen consumption is a relaible way to discern metabolic rate |
Q3-J | Soda lime binds carbon dioxide. Size, temperature, activity level, etc. affect metabolic rate. |
Q3-K | Simplicity in experimental design is just as good for qualititative research |
Q3-L | From the experimentation that I did in particular, I will learn that when you come up with improbable results, you should look into all the possible reasons as to why you might have gotten those faulty results. I also learned that even though you may not have come up with the results that were expected, it doesn't mean that the experiment was a failure. Rather, it was a learning experience. |
Q3-M | I will remember that the Northern Leopard frog and the Western Fence Lizard have statistically different metabolic rates even though they are both ectothermic. The lizards consume a greater amount of oxygen per gram than does the Northern Leopard Frog; however, the frog has a higher metabolic rate. |
Q3-N | In colder temperatures, endotherms must increase their metabolic rate in order to maintain their body temperature. |
Q3-O | That when body mass increases, the metabolism will decrease. |
Your Answers to Question 4:
Q4 | Question 4. What was one idea, concept, or principle that you really did not get from the lab (and the follow-up classroom discussions), that you feel you were really were supposed to understand? [#4] |
Q4-A | I am a little confused on the idea that when body mass increases, oxygen consumption per kilogram decreases. I cannot picture this happening in my mind; it is a matter of seeing the concept working in my mind. |
Q4-B | I did not fully understand the proper methods that should have been used to convert and compare our results to published results. i.e.: the conversion of different types of data from different experiments and searching for a relations ship there. |
Q4-C | Actually, I had a very good understanding of the metabolic rates of endotherms versus ectotherms by the end of this lab. |
Q4-D | We did the experiment but I do not feel I quite grasped why endotherms had a higher metabolic rate than ectotherms. |
Q4-E | I did not understand why oxygen consumption per unit body mass increases when the body size of organisms (and in this case mammals) increases. |
Q4-F | Why we calculate metabolism in ml/g*hr….what was wrong with using seconds? |
Q4-G | I really did not understand what I was looking for in terms of the difference between an endotherm and an ectotherm. I thought that the endotherm, hamster, would have a higher metabolic rate than the ectotherms, lizards, however this was not the case. I am not sure if our results are wrong or if it is possible that our results are right. If we shared results as a class or even discussed our results I may have a better understanding what our results mean. Therefore I could evaluate our results and make some definite conclusions from our experiment. As mammals increase in size their metabolic rates decrease but I don't think that a hamster qualifies as a particularly large mammal so I do not know why our determined metabolic rate is so low, even lower than the lizards. |
Q4-H | I don't think we actually discussed our results as a class and I think that is part of the reason I do not understand our results. Our book clearly goes into the difference in metabolic rates compared to body mass for mammals. However, there is no clear distinction for body mass and metabolic rates between ectotherms and endotherms. I have never taken ecology, and therefore I may be at a loss, but I am assuming that most endotherms will have higher metabolic rates than ectotherms. I wish that we could have taken a few minutes to discuss our results like we have in the previous two labs and then maybe the distinction in rates would be more clear. |
Q4-I | what the slopes of the lines in the graphs btw O2 consump and mass (other than there is a relationship relating the two) |
Q4-J | The data from the experiment had a standard error; showing/ expressing that standard error on a data plot made in excel took us forever. A quick demonstration of how to get standard error and put it into an excel graph would be very helpful. Also the type of t-test needed to find if there was a significant difference between the oxygen consumption of two animals could have been specified/ talked about because not everyone in the class took Bio 299. |
Q4-K | I probably did not understand what my experiment answers till the next day |
Q4-L | I didn't really understand why ectotherms that are in lower temperatures have a lower metabolic rate than those that are in warmer environments. |
Q4-M | I would like to learn about conductance more in depth. I did not fully understand the equation that was presented in class where Q=C*(Tb+Ta) + Evaporative heat loss. I feel that this is an important equation to know. Therefore, I feel that the meaning of this equation should have been explained more in detail. |
Q4-N | I believe I am unclear as to what the slopes of the line actually represent. |
Q4-O | I understood that body size influences metabolism, but I didn't understand why. |
Your Answers to Question 5:
Q5 | Question 5. What was one idea, concept, or principle that you wanted to learn more about had there been more time? [#5] |
Q5-A | Had there been more time I would have liked to test the metabolic rates of the cold acclimatized and warm acclimatized frogs in the colder (10oC) environment. It would be interesting to compare these results with those of the frogs tested at room temperature. |
Q5-B | I would want to test other animals. We just tested ectotherms in our experiment, however, I think that it would be better if we had compared them to endotherms. |
Q5-C | I would like to have also run our experiment on a reptile species as well and observe, first hand, the effects of temperature changes on metabolic rates of endotherms. Seeing our data match published findings and trends was very motivational and provided a great deal of reinforcement that our experiment did in fact work as expected. I think having the opportunity to also gather data on an ectotherm would have provided further comprehension of the concept and allowed us to make comparisons between the two groups. |
Q5-D | I would have like to have tested the metabolic rate of the Siberian hamster in a much hotter environment to see how it effected their metabolic rate. |
Q5-E | Same as above, it would have been interesting to investigate and understand why and how does body mass have and effect on the oxygen consumption per unit mass in animals. As animals getter bigger the less oxygen consumption per unit mass. |
Q5-F | What is the affect of cool and hot temperatures on reptiles and how does this compare to the hamsters? |
Q5-G | Based on my answer to question 4, I would like to learn more about the difference between the metabolic rates of ectotherms and endotherms. I know we covered this briefly in class but since I am having trouble assessing our results I think I should learn more about the difference in metabolic rates. If there had been more time and viability of animals, I would like to have measured the metabolic rates of a number of different ectotherms and especially a number of endotherms. |
Q5-H | I would definitely want to learn more on the specifics about metabolic rates for endotherms versus endotherms. As per my reasons in question 4. |
Q5-I | stadard metabolic rates - what affects them and what they should be |
Q5-J | Given more time I would have liked to measure the oxygen consumption of more then two animal species. For example, if we used a Siberian hamster as well as the lizards and frogs we did use, we would have had data for a mammal (endotherm), as well as the lizards and frogs (ectotherms). In addition, other reptiles and/ or amphibians oxygen consumption could have been measured in order to get a better understanding of how much oxygen consumption varies among different reptiles and amphibians. |
Q5-K | I would have liked to see what the more sophisticated experimental set up would have shown |
Q5-L | I would like to know why there is a difference between the metabolic rates of lizards and frogs. |
Q5-M | I thought that it would be interesting to learn more about the total amount of energy in food. For example, I think that it would be interesting to learn more about the method of doing this using the bomb calorimeter to measure the amount of calories in the excretions such as urine or fecal matter as well as the amount of calories that the animal consumes. It would also be interesting to find out about how much of the energy the animal actually uses. |
Q5-N | Since my group worked only with the endotherms, I would have like to been able to change the model of the experiment so each group could have done a comparison of endotherm versus ecotherm using the hamster and the lizard. |
Q5-O | I would have liked to learn more about the actual reasons that body size does indeed affect metabolism. |
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Please send comments to me: grant@pop1.science.widener.edu. Copyright: Bruce W. Grant and Itzick Vatnick, 2003 |