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. Please briefly summarize in a short paragraph the results YOU found with your investigations from the first lab: "Measuring and Modeling the Theory of Cooling" (CoolingLabStudentResults.xls). [#1] |
Q1-A | Results showed that the rate of cooling of water was exponential. The rate of heat loss at the beginning of the experiment was high but as time went on the rate of cooling became less until it became constant (the water reached room temperature). When the ln of the change in temperature was plotted against time, it showed a linear relationship between change in temperature as time goes on. |
Q1-B | At room temperature 15ml of water cooled faster in a 15 ml falcon tube then in a 45 ml falcon tube because the 15 ml tube had a greater surface are to volume ration then the 45 ml tube. In other words, more water was touching plastic which absorbed heat in the 15 ml tube than in the 45 ml tube causing the water in the smaller tube to cool faster. Because volume was held constant, the surface area of the tube that the water was touching is the main explanation for the greater cooling in the smaller tube. |
Q1-C | Our experiment did not work out properly. We did not obtain useable data. |
Q1-D | We hypothesized that the larger container would cool less rapidly than the smaller container of water. We found that the larger container took a longer amount of time to cool than did the smaller container. The slope for the smaller container was -.043 and the slope for the larger container was -.033. |
Q1-E | Our investigation was of the heat change in different size containers. This was to simulate small organisms and larger organisms. What we hypothesized was that the larger container would cool slower than the small container. Our finding when our large container cooled slower than our small supported this hypothesis. This suggests to us that larger organisms cool slower than small organisms. This result is most likely due to increased surface area per volume for the smaller container. |
Q1-F | In this lab we determined heat loss values of boiling water in an insulated and un-insulated falcon tube. After plotting the natural log of our heat values we were able to determine that the insulated falcon tube was 20 times more resistant to heat loss than the non-insulated falcon tubes. The take home message: Insulation helps prevent heat loss. |
Q1-G | For our investigation we compared insulated versus non-insulated falcon tubes. We plotted our results in excel with the ln of the change in temp vs. time. This graph indicated that the insulated falcon tube was 20 times more resistant to heat loss than the non-insulated falcon tubes. |
Q1-H | Rate of heat loss of an uninsulated tube is 20x that of an insulated tube. Hence, when an object is insulated it losses less heat to the environment as when an object is not insulated. Insulation is a determinate factor in heat loss. |
Q1-I | The variable in the experiment was the surface area to volume ratio. In order to perform this experiment, two different size falcon tubes were utilized- a 45-milliliter tube and a 15 milliliter tube. Both tubes were filled with an equal amount of boiling water (15 milliliters). The temperature was then recorded in order to assess rate of cooling. It was then found that the 15-milliliter tube, which had the greater surface area to volume ratio cooled more quickly than the 45-milliliter tube, which has a smaller surface area to volume ratio- specifically 33% faster. Therefore, bigger objects will cool slower than smaller objects. |
Q1-J | Our results indicated that the rate of cooling was the highest initially when the temperature was the highest. As time increased and the temperature began to decrease, the rate of cooling was considerably less than at the outset of the experiment. There is clearly a nonlinear relationship in the relationship of temperature cooling and time. |
Q1-K | Our equipment did not work. |
Q1-L | Our investigation focused on the effects of insulation on heat loss/cooling rate of hot water. The water was placed into a test tube and temperature readings were recorded and plotted. This was repeated for an non-insulated test tube and a test tube insulated by a winter glove. Our data supported our hypothesis that the insulated test tube would cool at a slower rate due to the insulative effects of the glove. |
Q1-M | Through our investigation we learned that between insulated falcon tubes and un-insulated falcon tubes there is a slight variation in the rate of cooling. Specifically that the insulated tube has a slower rate of cooling than an un-insulated object. This should be obvious since during the winter we insulate ourselves to conserve heat, and during the summer we keep as little insulation as possible on ourselves. |
Q1-N | In our experiment, we measured the rate of cooling for two different sized containers. One container was 45 mL; the other container was 15mL. It was found that the 15mL container’s rate of cooling was 33.3% faster than the 45mL container. |
Q1-O | We did not obtain correct information. When we graphed our data on excel, we realized the numbers were incorrect. There was not enough time to redo the experiment. |
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 first lab: "Measuring and Modeling the Theory of Cooling"? [#2] |
Q2-A | 1 – The rate of cooling of water is an exponential relationship, and then applying that to living organisms 2 –The rate of cooling of an object can be expressed mathematically. 3 -That there are different factors affecting the rate of cooling of water or any object. |
Q2-B | 1 - Many environmental factors influence heat loss, including: wind speed, surface area to volume ratio of the object, insulation, Evaporation, and Radiation cooling. 2 - Temperature and heat are not synonymous. Temperature is a measure of collisions between molecules. Heat, a thermodynamic concept, is the energy generated by those collisions. 3 - The rate of cooling does simply equal the change in temperature over the change in time. |
Q2-C | 1 – Temperature is the most important factor that effects plants and animals. 2 – The environmental factors that affect the rate of cooling are: air pressure, the size of the object, wind speed, insulation, heat capacity, evaporation and radiation cooling. 3 – The temperature difference or the voltage difference drives heat flow/energy flow. |
Q2-D | 1 - the rate of cooling of an individual depends on many variables. 2 - some of the variables are body mass, insulation. 3 - an animal that is larger or has more insulation than other individuals does not have to work as hard to maintain their body temperature…they cool more slowly. |
Q2-E | 1 – Body temperature regulation is important to organisms 2 – Body size, insulation, and amount of wind flow all effect how fast an organism cools 3 – Thermodynamics is a very energy consuming part of the energy budget |
Q2-F | 1 –There are many factors effecting the rate of cooling, i.e. insulation 2 – To understand the general equation behind the rate of cooling (change in body temperature/ change in time) 3 – How to design a model demonstrating heat loss and heat transfer as well as produce an excel spreadsheet displaying the results |
Q2-G | 1 - There are several environmental factors that effect the rate of cooling 2 - the rate of cooling is equal to the change in body temperature/ change in time 3 - the importance of and how to model the process of heat transference |
Q2-H | 1 – Rate of cooling is determined by many additive factors (slope dependent on these factors when plotting time vs body temp) 2 – rate of cooling can be determined via a calculation – ln Tb = ln (e#^-kt) 3 – basis of understanding of the different factors of cooling : wind speed, body size, insulation, evaporation and radiational cooling. |
Q2-I | 1 - Different environmental factors have an effect on the rate of cooling such as air pressure, size of wind speed, size of the object, insulation, humidity and radiational cooling. 2 - The rate of cooling can be expressed as an exponential relationship with temperature of the specimen as a function of time. This exponential relationship can then be changed into a linear relationship with the equation of (ln Tb/C)= -kt, where k is the slope of the line, which provides a rate at which the object cools. 3 - As an object cools, its temperature eventually becomes constant as time reaches infinity, provided that the temperature of the surroundings does not change. |
Q2-J | 1 – How objects cool 2 – What affects the rate of cooling of a heated object 3 – What affects the steady state temperature |
Q2-K | 1 - Many factors affect the rate of cooling including insulation, size of object, temperature of the object, temperature of the surrounding environment. 2 - The rate of cooling over time is a curve. If the natural log of temperature difference is used, then the rate of heat flow is linear. 3 – Different factors affect the shape of the curve at different rates. |
Q2-L | 1 - Environmental factors that influence heat transfer include; air pressure, size of object, wind speed, insulation and evaporation 2 – Understand modeling and construction of heat transfer 3 – Temperature difference is the main driver of heat flow. |
Q2-M | 1 – Rate of Cooling is dependent on Multiple Factors 2 - Animals have to perform many different functions to conserve heat 3 – Measuring Cooling can be done reliably. |
Q2-N | 1 - The factors that have an affect on the rate of cooling. 2 - In what ways do the factors work to affect the rate of cooling. 3 - |
Q2-O | 1 - to learn the environmental factors that effect the rate of cooling 2 - temperature is the most influential factor 3 - why and how wind effects the rate of cooling |
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 | That there are many factors that affect how an object or even an organism can loose heat or gain heat (size of object, wind speed, insulation…etc.). |
Q3-B | All the environmental factors that influence heat loss interact. Heat can only pass from an object at a higher temperature to an object at a lower temperature. |
Q3-C | Before Analyzing data and jumping to conclusions, you should always check to see if the data makes sense. |
Q3-D | I learned that although the slope of the two different containers was not that big of a difference; in an animal that rate of cooling is very important. |
Q3-E | Large animals cool slower than small animals |
Q3-F | I will definitely remember to wear gloves on my hands in the winter to prevent heat loss. I will also remember how different environment factors influence heating and cooling in organisms, especially in ectotherms. |
Q3-G | How important it is to thoroughly consider an organism's environment and how it affects their body temperature. I thought that the slides you showed on the lizards that you studied this summer clearly demonstrated how much the temperature of their habitat affects the lizards' behavior. The fact that they could only search and digest food at certain times of the day depending on the rising and setting of the sun clearly backed this principle. |
Q3-H | insulation controls majority of heat loss- wear gloves |
Q3-I | I have learned that the surface area to volume ratio of a specimen affects its rate of cooling. Therefore, if a specimen has a large body mass, the surface area to volume ratio will be small, thus leaving the organism to cool at a slower rate than an organism that is small and has a larger surface area to volume ratio. |
Q3-J | Allen’s Rule: Limbs will be shorter and bodies will be bigger in colder environments. |
Q3-K | I will remember that even when performing these experiments, that other factors can also have an affect on the rate of cooling. If you are testing the size of the object, the surrounding environment while testing will have an affect. For example, one trial could have a warmer surrounding environment than the next because of wind. |
Q3-L | The existence and function of the boundary layer. I never knew it existed, but it’s introduction in this lab helped to clarify why cool air/wind cools things off. |
Q3-M | I am going to remember that thermoregulation of animals is dependent on so many factors and not easy to maintain. |
Q3-N | I will remember some of the environmental factors that affect the rate of cooling, such as air pressure, size of the object, wind speed, insulation evaporation, and radiational cooling. |
Q3-O | To double check the data, make sure it is logical before leaving the lab to graph it. |
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 remember discussing Allen’s rule and Bergman’s rule and how they apply to endotherms, but I did not get the principle or the idea behind it and I felt that I was supposed to understand it. |
Q4-B | The concept of convective cooling and the boundary layer of dead air, and why a larger object would have a larger boundary layer. Is the convective heat being lost, "being lost to the surrounding air?" The physics of this subject could have been discussed better in that not everyone in the class has taken physics yet at Widener. |
Q4-C | I did not leave the lab with a clear understanding of the program that was used with the calculator. |
Q4-D | I didn't understand why we took the natural log of the body temperature - room temperature |
Q4-E | the discussion of why there is more surface area for a small organism |
Q4-F | I did not understand the derivation of the equation we used in lab, Tb= #e –KT. I did not understand how we derived it and more importantly, I kind of missed the purpose of using the equation. I got caught up in trying to derive the equation and missed the purpose behind it. |
Q4-G | I was a little confused while we were working with the derivations for the equation Tb= e-kt I am sure that we are not expected to know the calculus part of the derivation but I am not actually sure what this equation equilibrates with, or its purpose. |
Q4-H | the basis of convective cooling an it’s affect upon the entire process |
Q4-I | Convective cooling was difficult to understand with respect to the cooling rates of a particular organism. For example, the discussion addressed the question of how wind affects the rate of cooling on an organism. In order to understand this topic, prior knowledge of convection would have been helpful. However, not everyone in the class took physics, which limited my understanding of the topic. I am still not comfortable with the concept of there being a boundary layer of "dead" air or that the boundary of air is larger in larger objects. |
Q4-J | I did not understand the entire calculation process of the experiment. We used differences in temperatures at infinity and used logarithms to obtain a slope. I did not understand what temperature differences we were using and what they represented. |
Q4-K | In the final equation, the number symbol (#) is used for some number. What exactly is this number? And if it’s not needed, then why have it in the equation to begin with? |
Q4-L | I guess the part I’m most unclear on would be that of radiational cooling. I’ve always heard the term and understand it more thanks to your explanation but that would be what I’m still most unclear on. |
Q4-M | I believe the equations were hard to understand. The cooling equations truly depend on some understanding of physics (which I have none). |
Q4-N | I wasn’t completely clear on how some of the equations that we were shown worked. Sometimes I wasn’t sure about what value to plug in and where to plug it in in order to obtain the result that was needed. |
Q4-O | I did not understand the discussion on why wind effects the rate of cooling (convective cooling). It was too fast for me to completely comprehend. |
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 | We went briefly on how animals adapted to living in different environments. For example, in cold climates animals tend to have shorter limbs (being spherical). If we had time, it would have been nice to go into more details on this matter. |
Q5-B | Insulation "keeps heat in" but there are different types of insulators and conductors. Learning about different kinds of insulators and conductors would have been interesting. Why are some materials better or worse conductors and/ or insulators. For example, which is a better insulator fur, feathers, scales, etc and why? |
Q5-C | I would have tried different insulation techniques and I would have used different sized tubes. That would have compared insulation materials and it would compare the effects of size. |
Q5-D | I would have liked to have been able to run the experiment using the glove (insulation) and see how that would have affected small vs. large containers and the rate of cooling. |
Q5-E | Which takes priority? Does body size, wind, or insulation effect the organism the most? |
Q5-F | I would like to have spent more time investigating different variables, which can reduce heat transfer. We were only able to investigate one variable but I would like to have investigated. I think as an experiment it would have been cool to try to create a way to minimize heat loss as much as possible and maybe have the different groups in class compete against each other. |
Q5-G | Since the class comparatively looked at each other's results we did get a chance to see how different environmental factors affected the cooling rate, but I think it would have been more beneficial had we had more time to carry out other experiments in our group. We had originally wanted to compare insulated versus non-insulated falcon tubes with 3 different sizes. This way we could have looked at size differences (surface area) and insulation at the same time. |
Q5-H | the affects of the starting temperature of the object in question – do hotter liquids cool more quickly, is it constant throughout all liquids independent of initial temps…. |
Q5-I | I would have liked to learn more about how different organisms whether ectotherm or endotherm respond to an environment where an extreme temperature exists. For example, humans sweat when it is hot, dogs pant, but what do lizards do besides find shade to cool themselves? An in-depth look in to how an animal rids itself of excess heat in extreme temperatures would have been interesting. |
Q5-J | Had there been more time, I would have liked to test a couple of variables at one time. For example, testing bigger and smaller containers, while adding in insulation. Also, maybe even trying to determine what affect the surrounding temperature has on the rate of cooling. |
Q5-K | We all conducted work on wind speed, insulation and test tube size but if we could have also done some modeling on evaporation (obviously more involved than what we did) I think that would have been interesting also. |
Q5-L | I would have liked to have learned about the affect of cooling in a colder liquid. |
Q5-M | I would have like to have some more information on how air pressure affects the rate of cooling. We didn’t really go into much detain as to the reason why it does, and I am pretty interested to know why. |
Q5-N | I would have like to go into more detail regarding insulation effects on the rate of cooling, since that is what we did our experiment on. |
Your Answers to Question 6:
Q6 | Question 6. Please briefly summarize in a short paragraph the results YOU found with your investigations from the second lab: "Modeling and Measuring Lizard Operative Environmental Temperatures" (TbLizStudentResults.xls) [#6] |
Q6-A | In our experiment we measured the difference in body temperature at different places (light, tangent and shade). Our results showed that in places with direct sunlight the temperature of the lizard is really high. At tangent sunlight the temperature of the lizard is less, and the temperature is the least in the shade. |
Q6-B | Position affects how a lizard can regulate its temperature. In a prostrate position, the lizard has the max body surface area in contact with its substrate, from which it absorbs heat; thus its body temperature is highest in this position. In an elevated position, the lizard has a minimum amount of its body surface area in contact with the substrate it is on; therefore the lowest body temperature occurs at this position. In a "heat up rear down" position, the lizard has a medium amount of its body surface in contact with the substrate it rests on; therefore a body temp between the temperature for prostrate and elevated positions is observed. |
Q6-C | We found that the wind speed and the change in the temperature of the lizard’s body were inversely proportional. As the wind speed was increased, the lizard’s body temperature decreased. This comparison held true in the computer simulation and in the real experiment that we performed outside on the roof. |
Q6-D | We hypothesized that the temperature of the lizard would be the greatest when the lizard was oriented so that the sun would hit the lizard's top view. The data from the simulation showed this and that the end view of the lizard was the least hot. The data from the experiment we ran on the top of Kirkbride showed that the top view of the lizard was the hottest and the end view of the lizard was the least hot. The data from the simulation and experiment followed the same trend although the temperatures were slightly off. |
Q6-E | We studied the change in mass and how it affects body temperature and also how wind speed affects this. In general we found that the smaller animals cooled the greatest and the larger animals stayed the warmest. At low winds we found that there is a bigger difference in the animal’s body temperature than at high wind speeds. Therefore, body size became almost negligible at high wind speeds. |
Q6-F | In this lab we investigated the effects of color on body temperature of a lizard model. We used four different color tapes (white, blue, red, black) to change the color of the lizards. Body temperature of each lizard was measured after five minutes and ten minutes. We found that in both by changing color (Absol) from light to dark, the lizard’s body temperature increased almost five degrees after five minutes. We found that after ten minutes the body temperature also increased, but these temperatures were lower because a strong wind past by. |
Q6-G | For our variable Jon and I used color. We wrapped lizards in a different color of tape, and then placed them in direct sunlight. We found that the darker the color of the tape was the greater the change in body temperature was after 5 minutes in direct sunlight. We speculated that after 10 minutes in direct sunlight the change in body temperature would be slightly increased. However, due to a considerable increase in wind speed after 10 minutes are body temperatures had actually decreased. This allowed us to simultaneously look at the effects of color change and the cooling effects of wind. |
Q6-H | we found that body size has some effect upon body temp at low wind speed, but once wind speeds increase beyond a certain point body size is no longer a determinate variable of body temperature. The range of variance of body temp in relation to size of the object in question was actually quite small, no larger than 4 degrees. |
Q6-I | The body temperature of a copper lizard was tested with respect to a certain body position. For example, temperatures of lizards were assessed in an elevated position, head-up posterior-down position and a prostrate position. From the results, it was demonstrated that the position of the lizard does have an effect on its body temperature. In the case of this experiment, the lizard's body temperature was highest when fixated in a prostrate position. The speculation for this finding was that the lizard's full underbody was in contact with the hot ground, and the upper body of the lizard was in contact with the sun. The other two positions did not allow for the lizard to come into the greatest amount of contact with the hot ground, thus the temperatures for these two positions were lower than the prostrate. |
Q6-J | In regards to the lizard’s heat budget, position in relation to the sun is fairly significant. As expected, when most exposed to the sun in the top view position, the lizard’s temperature was the highest. To maintain a certain body temperature, the lizard can manipulate its position relative to the sun in various ways and thus, maintain a certain heat budget. |
Q6-K | In our experiments, we tested the affect of wind speed on the body temperature on lizards. In the simulation, the results indicated that with greater wind speed, the body temperature of the lizard decreased. Also, the simulation indicated that there is a greater decrease in body temperature when starting from zero wind speed to 2-3 m/s. In the actual experiment on the roof, the results indicated that the greater the wind decreased the lizard’s body temperature. |
Q6-L | Our investigation was on the effect of body orientation toward the sun and its effect on body temperature in the lizard. Our predicted values from the computer model correspond with the experimental values we observed during our experiment. Each followed the same trend as seen in our graph. The highest body temperatures were recorded while the sun was directly above the lizard, midpoint values were observed while the orientation was oblique and the lowest body temperatures came from the end orientation. This shows that body position plays a key role in lizard body temperature. |
Q6-M | In our investigation we found that the place a lizard chooses to stay in had a huge correlation to the temperature the lizard will become. If a lizard is in sunlight it will be much higher in temperature than if the lizard was tangent to the sun or in the shade. Hence an easy way to thermo regulate is to go to a shadier region. |
Q6-N | In our experiment, we tested three different body positions- prostrate, head up head down, and elevated. Our objective was to see which position caused the lizard to get higher in body temperature. I was found out that the lizard gained the most heat while it was in the prostrate position--I assumed that this was because the lizard had the most surface contact in this position. Also, the lizard had a lot of foil underneath if while in this position--foil is a good conductor of heat. The lizard gained the least heat while in the head up, body down position. |
Q6-O | We used model lizards, a fan and a temperature apparatus. We found that the faster the windspeed, the cooler the body temp of the lizard was. |
Your Answers to Question 7:
Q7 | Question 7. What were three of the main ideas, concepts, or principles that you were supposed to understand and take with you from the second lab: "Modeling and Measuring Lizard Operative Environmental Temperatures"? [#7] |
Q7-A | 1 – animals can change their body temperature behaviorally, going from sun to shade. 2 – The temperature of a lizard can be measured from the total energy gained and from the total energy lost. 3 – There are many factors affecting body temperature. Lizards can loose heat by radiation, convection and conduction but not through evaporation due to their thick layer of skin. |
Q7-B | 1 - In the field it is nearly impossible to hold all other variables constant in an effort to study one variable in particular. 2 - The largest factor that influences how a lizard can regulate its temperature is whether or not it is in or moves to direct sun, some shade or full shade or a combination. 3 - Computer heat exchange simulations show general tends but they cannot accurately predict the outcome of field experiments. |
Q7-C | 1 – Heat exchange has 3 main mechanisms: radiation, convection, and conduction. 2 – We lose the most heat thru infrared heat radiation. 3 – Insulation is used to reduce the surface temp and this prevents infrared heat loss. |
Q7-D | 1 - An lizard's body orientation to the sun affects its body temperature 2 - The color of a lizard affects its body temperature when in the sun. 3 - Whether or not the lizard is elevated or flat on the ground has an effect on its body temperature. |
Q7-E | 1 – Ectotherms use many tactics of cooling themselves (sitting up, shifting, moving, changing colors, etc.) 2 – The biggest tactic an organism can use is physically moving from the sunlight into the shade 3 – Ectotherms need to keep themselves cool easily in order to conserve energy |
Q7-F | 1 – To the study the three major processes of heat transference effecting organisms (conduction, convection, and radiation) 2 – To study the different ways which an organism can effectively alter its body temperature 3 –Using software to investigate how different environmental factors, such as wind speed, time of day, humidity, etc. affect an organisms body temperature |
Q7-G | 1 - To thoroughly understand the three processes of heat transference -radiation, convection and conduction. 2 -That an organism has a way of changing its behavior or adapting itself in order to increase or decrease the effects of the environment on its body temperature. These would include changing its color, or its posture. Also included are things as simple as moving into or out of the shade. 3 - How to use the software in order to decipher how many different environmental factors affect and organism's body temperature. The software allowed us to include many variables that as a class we could not carry out in lab. |
Q7-H | 1 – body temp of ectotherms is dependent upon wind speed, air temp, light, heat conductivity of surface, convention exchange, IR out and evaporation 2 – dominant means of heat loss is due to IR (skin temp loss / gain) if surface is reduced than tamp is held 3 – heat loss – heat gain = zero |
Q7-I | 1 - Heat is transformed through radiation, convection and conduction. 2 - Ectothermic organisms such as lizards can change their temperature according to many factors such as orientation to the sun, movement to a shaded area, posture, wind speed and changing their color. 3 - Ectothermy includes the disadvantage of working harder to find somewhere to regulate body temperature; whereas endothermic organisms can regulate their own body temperature. |
Q7-J | 1 – The dominant way we lose heat is through infrared radiation 2 – Lizards can maintain a heat budget through manipulating various factors such as orientation to the sun, position, color and moving into the shade. 3 – Heat exchange occurs through the 3 main mechanisms of radiation, convection, and conduction. |
Q7-K | 1 –The three main factors that affect the steady state temperature are radiation, convection, and conduction; infrared radiation is the most dominant factors. 2 – Body heat can be conserved by reducing the skin temperature of the lizard. 3 – Many different variables can be tested during experimentation including posture, orientation, wind speed, coloring, and whether or not the lizard is in the sun or shade. |
Q7-L | 1 – There are 3 heat exchange mechanisms; radiation, convection and conduction. 2 – The dominant way that we lose heat is through infrared radiation. 3 – Body orientation in the sun or shade play the biggest role in lizard body temperature. The animal itself has the most control over this variation. |
Q7-M | 1 - Thermoregulation is dependent on many factors 2 - Animals in many environments can only be active at specific times in there “cycles”. 3 – Water loss is negligible in lizards. |
Q7-N | 1 - Heat is exchange between the object and the environment in three different ways--radiation, convection, and conduction. 2 - Infared radiation accounts for most of the heat that an object/lizard looses. 3 - There are more than one ways that a lizard can change its body temperature. For example by moving to the shade, it can cool off; it can change its orientation to the sun, and change its posture. |
Q7-O | 1 - IR heat loss is dominant reason for heat loss 2 - lizards change body temps by: the orientation of the sun, going into the shade, changing body position, changing weight, and wind speed 3 - we can predict trends if we know some info of the environment |
Your Answers to Question 8:
Q8 | Question 8. What was the one thing you learned from this lab that you will likely remember a year from now? [#8] |
Q8-A | That the temperature of an organism depends on many factor, and on the environment surrounding it. |
Q8-B | Temperature affects the times of day an animal can safely be active and or digest its food. |
Q8-C | We loose the most heat from out extremities….wear a hat. |
Q8-D | I will remember how the different factors such as wind, orientation to the sun, and body posture effect the body temperature of the lizard. |
Q8-E | Ectotherms are animals that change their temperature depending on their environment and they must achieve a high enough temperature in order to digest their food. |
Q8-F | The one thing I learned in this lab I am likely to remember a year from now is how simply an ectothermic organism, like the fence lizard, can alter its body temperature a few degrees. For instance, by simply lowering or elevating it’s head or adjusting it’s body position relative to the sun a lizard can lowering it’s body temperature 3-4 degrees. |
Q8-G | How important skin color is for many organisms. Without the ability for some lizards to be able to change the color of their skin they would most likely overheat. |
Q8-H | wear clothes they help keep heat in |
Q8-I | One year from now, I will have remembered that position of an ectothermic organism such as the lizard does have an effect on its body temperature because I performed the experiments and analyzed the data with my group. From watching the experiments of others, I will also remember the different factors that affect the body temperature of an ectotherm such as the orientation to the sun, movement into shade, its color and the speed of the wind. |
Q8-J | The operative environmental temperature is the temperature of a body at which heat gain exactly equals heat loss. |
Q8-K | Even the orientation of animals in the sun has an affect on their body temperature. I did not realize that the posture of the body could increase or decrease the body temperature. |
Q8-L | Infrared radiation is proportional to the 4th power of skin temperature. |
Q8-M | The variations in temperatures due to factors we take lightly, like wind, body position, and sunlight. |
Q8-N | I will remember the ways that a lizard can change its temperature. I will also remember that ectotherms have a lower rate of metabolism than endotherms. |
Q8-O | The mechanisms of heat exchange for animals are: radiation, convection, conduction. |
Your Answers to Question 9:
Q9 | Question 9. 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? [#9] |
Q9-A | I did not exactly understand the effect of convection on the temperature of the lizard (i.e. what role does convection exactly plays on the temperature of the lizard). |
Q9-B | The heat loss computer simulation was important to the lab exercise, yet not all the variables were common sense. More time allotted to going over each variable and why it was a variable would have been beneficial. For example, the pyrometer measures the wattage output of the sun, which is an important variable and instrument to measure variable that is not necessarily familiar to the students. Actually showing the students the equipment to measure such a variable would be a bonus. |
Q9-C | I think that I display poor skills when it comes down to using excel efficiently. I think that I need a little more instruction in this area, but this course is not on excel, even though we use it daily. |
Q9-D | There was nothing that I can think of… |
Q9-E | How simple movements like head up affect body temperature? |
Q9-F | I really did not understand some of those equations we used in the program to calculate body temperature. I don’t think that we really had to know them since you explained the program quickly, but I didn’t understand them away. I was also curious why we did not account for conduction on the rooftop when measuring body temperature. Maybe my understanding of the effects of conduction on an organism’s body temperature is incorrect, or maybe since all the model lizards were on the roof they all experience the same effects from it. |
Q9-G | I had a lot of trouble understanding how the position of the lizard's head really affected his body temperature. I know that a group in our class did body position, but it just does not sit well with me that the angle his head is placed correlates to his body temperature. I just think I would need to read more about it to thoroughly understand how this works. |
Q9-H | all of the equations relating to heat loss / gain |
Q9-I | I did not fully understand the equation that was given for heat transfer. There were too many variables to the equation. These variables are definitely important when calculating heat transfer; therefore, more time should have been used to give an explanation about this complex equation. |
Q9-J | I do not understand the effects of all the factors on the animal’s heat budget. Particularly, since an animal does not necessarily control wind speed and mass, how can these factors be manipulated? |
Q9-K | I really did not understand how the simulation could simulate lizards out in the sun. Were there certain equations used that I missed in class? Can a computer program always accurately depict the outside environment that you wanted to depict. |
Q9-L | Oddly enough the principle that I won’t forget is probably the one I understand the least. I remember it because it was repeated several times but for whatever reason the actual meaning and interpretation of that statement never got through. |
Q9-M | The understanding of why animals are in specific physiological formation. Why is the head cylindrical and the body just as suck, does it reduce Surface area ratio’s? |
Q9-N | I did not understand why the lizard did not have the least heat while in the elevated position instead of the head up, body down position. Considering that the lizard had more surface contact while in the head up, body down position, than in the elevated position, I would have thought that the lizard would have gained more heat while in the former position. |
Q9-O | I am confused between the lecture and the lab. In my lecture notes I have 4 effects on body temp of lizards: convection, conduction, IR radiation, and evaporative water loss. In lab only the first three were discussed. Is evaporation not considered to be one of these effects? |
Your Answers to Question 10:
Q10 | Question 10. What was one idea, concept, or principle that you wanted to learn more about had there been more time? [#10] |
Q10-A | Same as above, I would like to have known the role that convection plays on the temperature of the lizard. |
Q10-B | Wind speed constantly fluctuates, so an ectotherm living in a windy region must constantly correct for that temperature change. What are some ways an ectotherm can accomplish this simply, that is without constant movement of its body to different areas, positions, orientations, etc. because these movements would waste energy. |
Q10-C | I would have tested different variables so that I could draw more conclusions on how they would affect the temperature and heat loss. |
Q10-D | It would have been interesting to take the different variables that each individual group had done their experiment on and then combined them such that to do an experiment with the color of the lizard varying, where it was in relation to the sun, and the wind speed. |
Q10-E | Do endotherms have some of the same habits of cooling themselves as ectotherms? |
Q10-F | The independent variable in our experiment was the lizard’s body temperature. We choose this as our variable because lizards can alter the color of their body in order to increase or lower their body temperature. I would have liked to spend more time investigating this, particularly to find out much a lizard can really alter its body color. Our model showed a change in body temperature of almost a full eight degrees. However, I would like to know, using a live lizard, how much color change really affects its body temperature because I find it hard to believe it could change it a full eight degrees Celsius. |
Q10-G | We did not spend enough time studying the effects of conduction. We discussed it in class but did not really consider it while carrying out the experiments. |
Q10-H | the eff4ects of conduction upon body temp – we did not even take it into consideration when we measured the body temp of out object – shouldn’t we have , or is the effect thereof considered negligible, did we assume it to be constant – does conduction have a large or small effect upon body temp in general? |
Q10-I | I would have likes to learn more about how an organism such as lizard camouflages itself in order to regulate its body temperature. The physiology of that particular process would have been interesting to delve in to further, provided that there was more time. |
Q10-J | I wanted to extend the experiment to different climates. Lizards are versatile animals with many bodily mechanisms at its disposal. But at colder climates and even more temperate climates, I am interested in knowing about the different manipulations available to certain organisms. |
Q10-K | I would have liked to learn more about using two or more variables at one time. For example, it is more advantageous for the lizard to be in one orientation to the sun during high wind speeds as opposed to another orientation. |
Q10-L | I thought we covered a great deal of factors in this lab, there is nothing that I can think of that I would like to investigate further. |
Q10-M | Same as Above |
Q10-N | I would have liked to know more about how ectotherms gained heat. What other ways do they go about obtaining heat within their system. |
Q10-O | I didnt fully understand the equation with Q in it. I felt we should have spent more time on it. |
Your Answers to Question 11:
Q11 | Question 11. Comment specifically on the modeling part. How have your ideas or attitudes toward quantitative research, and the use of computers to study and understand physiological ecology, changed as a result of your doing your own computer simulations? Please reflect upon this topic in at least one paragraph, and offer a critique not only your learning of these quantitative skills, but also of the lab activities in helping you to learn these skills. [#11] |
Q11-A | I think that using the computer simulation to predict the results of an experiment before actually performing the experiment is a very good idea. I think it actually helps us understand what the experiment is all about, making us think deeply of the theory behind the experiment. For example, making up numbers and data and making our predictions on what affects the body temperature of a lizard and actually producing a graph describing our prediction and then performing the experiment and collecting real data, then comparing the actual results to the predicted results, can show a lot about our understanding of the theory and subject being tested. |
Q11-B | The lab activity convinced me that the computer simulations are useful for predicting trends. However, the computer can fully hold all but one variable constant, which cannot be done in taking field measurements. In other words, the computer simulation can be useful to predict a general idea of what the results of physical measurement in the field will generate. But field experimentation will never produce results exactly the same as generated by the computer simulation because in reality all but one variable cannot be totally controlled. The computer simulation was for a lizard on a fence in west Texas. We used clay/ copper lizards on the roof of Kirkbride Hall in South-Eastern Pennsylvania, obviously the conditions in both areas would be different. Thus the model's prediction and the experimental data are inherently going to be somewhat different besides the differences due to not being able experimentally hold all but one variable constant. |
Q11-C | I feel that using computer simulations before actually going out into the field is very helpful. When you use the programs, you may get an idea of what type of results you should expect to obtain. When your results from the field are different from the computer simulations, you may question your observations a little more closely. (Why are my results different?? How could I change my experiment to obtain better results??) I think that using the modeling programs helped me to understand what I was looking for when we preformed the actual experiment. |
Q11-D | I was completely against using computer simulations to predict the outcome an experiment. From the lizard lab my opinion of this has changed. Although our temperatures were slightly off from the temperatures from the computer simulation our values still followed the same trend. One of the differences we did not account for was the mass of the lizard we did the experiment with and the mass of the lizard in the simulation; which could affect our results. I still think that the best way to do a quantitative and qualitative study is to do the study. When using a computer simulation program environmental factors that could affect the experiment are not taken into consideration. We ran the experiments with the same lizard and it's possible that the wind blew more at one point than it did at another point. |
Q11-E | Field research lets you know specifics although they are very hard to control. Using computer simulations are good because they can be used to show a trend. As for our research the data recorded may not be accurate for a lizard, but in general a large lizard will always cool slower than a small lizard. Computer simulations will also let you use hypothetical situations, like what if there was global warming and the lizards had to adapt to a 3 degrees increase. |
Q11-F | My feelings and attitude toward excel have not changed, I still can’t stand it. However, I especially liked the modeling part of the lizard lab because I thought it made the lab more interesting. It was more interesting because we were able to compare the predicted body temperature values with the values we determined experimentally. It is not as interesting n other experiments where experimental values are the only values we find because we do not have any other data to compare. I feel fairly comfortable with computer simulations from work in this class and previous work in evolution. I wouldn’t say that computer simulations are my favorite thing to do, but I feel that I am learning the topics that we studying better than just reading about them in a text book or sitting through a lecture. |
Q11-G | I thought that the computer simulation that we did in the second lab through Dr. Grant's program was very valuable in demonstrating how just one environmental factor can greatly affect an organism. This simulation was also helpful in guiding us in our own actual results as far as what we could expect to obtain and how other variables would affect the one our group choose. I think that the use of excel in modeling our results is also helpful in making the data easier to interpret. Even better is when Dr. Grant compiles all our graphs and we compare all the results together, this really gets the point across clearly. |
Q11-H | the run through using the software with the lizards initially did not help much because I did not grasp much from the multiple equations displayed, went through it very quickly, but being able to manipulate the different variables and see the outcome was very helpful in my understanding of the concepts and of using computer simulated modeling in general. Other than this we only used graphs, which does not really count as modeling and we have done them multiple times before. |
Q11-I | Using computers to generate models for the experiments above does not incorporate all of the variables that need to be taken into account because computers cannot do so. However, they do generate a general idea of the heat transfer/heat loss concept for an ectothermic organism such as the lizard. Models are helpful in speculating an organism's temperature in certain biophysical situations, but cannot give one the actual temperature of the organism. Copper lizards were used in this laboratory exercise, which again only give a general idea of the body temperature of a lizard placed in a particular environment. Computer programs such as the Texas Lizard Model are also inaccurate because they can control certain variables, whereas in nature one cannot. The modeling skills are helpful to see patterns of body temperature in a particular situation, but it would have been more accurate, although probably not feasible, to use real animals. Overall, the computer simulation did help me to see how different variables such as movement into shade, color, wind speed orientation to the sun and posture affect the body temperature in ectothermic organisms. |
Q11-J | The most important thing I have learned thus far in using the various modeling and computer methods is that generally the most important thing to look for is some sort of trend. Due to human error and differences in technique, it is very hard to obtain values that exactly match known values or published quantities. However, we are interested in trends that can establish a behavior pattern or explain what happens when conditions change. Often there are experiments when precise numbers are important, however, in this type of modeling, the computer graphing allows us to visually understand the bigger picture of things. Quantitatively, it is vital to understand the significance of major calculations. Why are we interested in finding the slope and taking logarithms? Without an understanding of such questions, graphing and ultimately understanding the larger scheme of things tends to become difficult. |
Q11-K | The computer simulations predicted that increasing wind speed would decrease the lizard’s body temperature. The actual experiment indicated that increasing wind speed does decrease the body temperature of the lizards. I did not think that the computer simulation could possibly depict the outside conditions correctly but this was not correct. The overall distribution of temperature versus wind speed was accurately displayed in the simulation. I am now more confident that the computer simulation can accurately depict the results. I think it useful to learn these skills in case there is ever an instance where you cannot physically go outside and perform the experiment. This would occur, when the conditions are too harsh to be outside. I believe that I could run the simulation on my own after learning the program in lab but there are some aspects that I do not know how to change or what would be accurate numbers for certain environmental factors. |
Q11-L | Modeling is a great tool that can be useful in generating predictions. We can use modeling and computer simulations in the lab to simulate various environmental conditions that would otherwise take too much time in the field, as well as be very difficult to control. Modeling allows you to control for all variables, except those being tested, to arrive at an answer to the research question. Though the model is simply a model or simulation, it can’t be truly representative of the actual physical environment and therefore, definitive answers cannot be applied from the simulation. However, the model can be used as a predictor of trends that may occur. Modeling is a good tool to use to begin an investigation or a lab activity like we had done because I think it’s a good idea to have an idea of the trend that may be observed instead of going into a study blind, not having any idea which direction the findings may go. Students can use it as a guide during their investigations. |
Q11-M | Through the modeling portion I have learned that computer modeling is easier than actual animal manipulation, but not as reliable. Factors that affect real animals are not made apparent in simulated models. Also I have realized how quantitative affects in physiological ecology are hard to keep unvaried. (too many variables when doing an experiment). Also I believe that its hard to distinguish where in lab ecology begins and physiology ends. I guess this is the point. On the other hand I have learned a lot about designing experiments and |
Q11-N | I think that the computer is a very helpful and useful device to do research with. There are many equations that the computer works out for you. The computer’s results are often more accurate than the results that you would obtain if you were to do the experiment yourself. The predictions that we came up with using the computer program at the beginning of class were very helpful. It helped me to get an idea about how my data should or might look like when the experiment was actually performed. |
Q11-O | The computer simulations were very helpful to me. Using the computer to model helps to make the concept more concrete, rather than just some idea out there. This way of approaching has definately enhanced and made the lab more comprehendable. I find that sometimes I lose sight of the purpose of a lab. But the computers have kept me on track. Honestly, this type of learning by modeling has interested me more than I thought it would have. |
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Please send comments to me: grant@pop1.science.widener.edu. Copyright: Bruce W. Grant and Itzick Vatnick, 2003 |