Biology 2601A/B Lecture Notes - Lecture 4: Countercurrent Exchange, Heterothermy, Exponential Growth
26 Oct 2013
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Document Summary
Climatic fluctuations in temperature are a part of everyday for all living organisms. Lecture 4: endothermic homeotherms: daily for example, night vs. day, fluctuations in tides, seasonal, temporal. Animals and plants need to manage climatic fluctuations. Regulating internal body temperature is necessary for cellular function. Departures from the set core body temperatures can lead to cellular damage or death of the individual. Homeotherm an animal that thermoregulates by physiological means, rather than simply by behavior: more independence from external thermal conditions, highly stable core body temperature. Adaptation of endothermic homeothermy has only arisen in birds and mammals: humans are classified as homeothermic endotherms. Origin of birds was nested within the dinosaurs and there was no close relation between mammals and birds thus the origin of endothermic homeothermy was independent between the two groups. Endothermy clearly permits mammals and birds to have an active life in harsh environments. Also permits long distant migration in birds and mammals.
