Metabolic Rates
...consumption. It increased to 0.93 x10 . Once again an optimal temperature for metabolic rate could not be found, because only two points were plotted. 1c)The standard errors of the mean( SEM) of the two data’s differ, with the SEM of the pooled data for both the crayfish and the mouse, being lower than the then SEM for lab section 15. This makes sense because we know that the SEM is calculated using the simple formula ,where n is the number of data points collected (group size) , is the individual data measurement, and is the mean average of all the collected data( group mean), E is the sum of the previous values. Therefore since there were more data points collected for the pooled data, the value for n is much larger. Since n is the denominator, the greater the value for n, the smaller the SEM will be. That is why the pooled data has a smaller SEM then the lab sections data which had less data points. 2a)The major difference between the mouse metabolic rates and the crayfishes metabolic rates is the crayfish exhibited a directly proportional relationship with the increasing temperature where, the mouse had an inverse relationship with temperature. Animals are said to be ectothermic when their own body temperature is determined by the interactions with their environment rather then their own metabolic heat that they produce. Some examples are fish, and reptiles. Animals are said to be endothermic or rather exhibit “endother y” when they regulate their own body temperature through physiological means such as metabolism. Regardless if the external environment they must maintain a constant internal body temperature to stay alive. (Campbell and Reece 2002). Being a member of the invertebrates the crayfish would exhibit ectothermic trends, and the mouse being a mammal would exhibit endothermic trends. Since the crayfish is dependant on its environment and the mouse is not, it accounts for the different metabolic rate relationships with the different temperatures for the two animals. 2b)Ectothermy evolved before endotherm . We can determine this by knowing that ectotherms include all invertebrates, which lack a backbone. The first species ever known to be on the earth were invertebrates and they evolved into vertebrates. Majority of the animals today are ectotherms, for 95% of the animals species are invertebrates. (Campbell and Reece,2002). There are many advantaged to being an ectothermic animal. Many fish and water animals are invertebrates and benefit from the water being resistant to change due to high to its high specific heat capacity. This helps the ectotherm to maintain its body temperature without a great loss of energy (Levine and Miller, 1994). Seeing as they require less energy due to smaller size this is quite beneficial for them , because they can invest their energy into reproduction, and growt...