BIOL 2200 Lecture Notes - Lecture 32: Poikilotherm, Thermoregulation, Osmoregulation
16 Apr 2017
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Homeostasis: maintaining internal environment at relatively constant conditions, conditions don"t need to be fixed. Maintaining a range that supports biochemical and physiological processes: regulation of temperature and ph/osmotic balance key. Bask in the sun, hide in the shade: endotherms: Control body temperature using internal energy (metabolic: poikilotherms: Maintain constant body temperature regardless of environment: poikilothermic endotherms increase or reduce metabolic rate in response to extreme temperature, homeothermic ectotherms live in near constant conditions. Costly to produce many different enzyme forms: endotherms. May have a more limited distribution (there are exceptions) Remain active in spite of poor conditions, unless they are lacking in food. Reduce heat gain: light leaves growing away from ground reflects sunlight. Increase heat loss: better air circulation increases convective heat loss: cold climates. Reduce heat loss; growing close to the ground, where heat can be absorbed through conduction. Increase heat gain by using dark pigments that increase absorption.
