Styles The body temperatures of ectothermic animals are mostly determined by the
ID: 282124 • Letter: S
Question
Styles The body temperatures of ectothermic animals are mostly determined by the outside environment whereas endotherms rely on heat generated inside their bodies to regulate temperature. Most ectotherms do regulate their body temperatures to some extent. For example, an ectothermic animal, such as a lizard, may move to a sunny spot to warm up or to a shady spot to cool down. Endotherms can maintain a stable internal body temperature even as outside conditions vary. Arctic foxes and polar bears, for example, maintain their body temperatures at about 38°C even as the air temperature dips down to -40°C. Ectotherms, on the other hand, cannot maintain stable internal body temperatures and generally cannot remain active across a wide range of external conditions. They are however better able to withstand wider internal fluctuations than endotherms. A freshwater bass fish, which is an ectotherm, can survive internal temperatures ranging from near 0°C to 35°C. An endothermic human could die if the person's internal temperature rises or drops outside a 5°C range (from about 35°C to 40°C). Write definitions for "endothermic" and "ectothermic" using your own words. List four examples of animals that would fit into each category. 2. How do endotherms maintain a relatively constant body temperature in different environments? They use the energy produced by breaking down food. Food is broken down by cellular respiration to produce energy in the form of ATP that is then used for all types of biological work, such as growing new tissues, locomotion, and reproduction. In the process of doing work, some of the chemical energy in food is converted into heat. Endotherms can also contract muscle fibers rapidly when shivering to generate extra heat when they are cold. Making a lot of heat, plus insulating fur and feathers (or clothes), allow endotherms to keep warm in cold environments The process by which cells use energy to do biological work is called metabolism. The rate at which animals transform chemical energy in food and release heat is the metabolic rate, which is measured in joules or calories per second. To keep a constant body temperature, endotherms generally have higher metabolic rates than ectotherms. At similar masses, the metabolic rates of endotherms at rest (their "resting metabolic rates") tend to be 5-20 times higher than those of ectotherms A major scientific principle is that energy is neither created nor destroyed, but it can be transferred or transformed. Summarize some of the transformations of energy described in the two paragraphs above. 3.Explanation / Answer
2) Endotherms ; organisms whose temperature is maintained internally, and sustain in an moderate temperature but has the drawback of not surviving in an wide range of temperatures eg. Humans, tiger, lion, polar bear
Exotherms; organisms whose temperature is directly depended on environmental conditions. And can survive in an range of temperature.
Eg. Lizard, snakes turtles and alligators.
3) As already known energy can never be made or destroyed it can only be transformed. In the given context this phenomenon can be elaborately explained, the food that endotherms consume has been synthesised by plants using sun light and water, this energy harnessed by plants when consumed by humans /animals the complex food substance are broken down into simpler substances like proteins lipids and carbohydrates.
The reaction involved during this catabolic reaction leads to production of heat along with ATP and other by products.
This heat helps in maintaining the temperature of the endotherms.
4) As birds belong to dinosaurs in their nature it can be said that some of the dinosaurs could have been endothermic in nature. But not all dinosaurs were endotherms as they belonged to reptiles which are ectothermic in nature
The differentiation can be done by examining the thin sections of bone. Ectotherms will have dense bone whereas endotherms will have haversian canal like system.
The results cannot be said to be conclusive in nature but can surely be used in distinguishing both the organisms.