Thermoregulation of Mammals Activity

Name: _____________________________________________ Date:______ How Do Mammals Maintain Their Temperature? (CER) Birds and mammals are endotherms, meaning that they produce and retain heat within their own tissues. This means that endotherms maintain a fairly constant internal environment. Ectotherms, such as reptiles and fish, absorb heat from the environment. Their body temperatures can fluctuate with the external temperature. Maintaining systems as a constant, stable level is called homeostasis. A cat is a placental mammal, or a type of mammal that incubates young inside their body. The opossum is a marsupial, a type of animal that incubates its young within a pouch. The platypus and echidna are both monotremes, a group of mammals that lay eggs. This graph shows the body temperature of different animals at different ambient (outside) temperatures. 1. The cat is regulating its body temperature, a process called thermoregulation. What EVIDENCE from the graph supports this CLAIM. a cats body temp stays the same nomatter the weather 2. How does the ectotherm (lizard) respond to an increase in the ambient temperature? it steadily rised 3. Compare the body temperature of the echidna at 10°C to its temperature at 30°C. it raises 4. Would the echidna be considered an endotherm or an ectotherm. Explain your REASONING. endotherm because its body temp rises 5. Temperature in mammals is maintained by using energy. Mammals must consume food to maintain homeostasis (or a constant state). Which animal would use the most amount of energy to maintain homeostasis? Explain your REASONING. A lizard because it is the smallest so it needs to www.biologycorner.com Most mammals that remain active in winter maintain a core body temperature of around 37-38°C (around 99°F). They have several adaptations that allow them to maintain a constant internal body temperature. Oxygen consumption rises as cells use energy, a measure of an animal’s metabolic rate. This energy is used to maintain the body’s internal temperature. 6. As the temperature increases from 10°C to 25°C, how does the oxygen consumption of the mouse change? it descreases 7. During what range of temperature is oxygen consumption steady? 25-35 8. Explain why the oxygen levels stay relatively stable in the ectotherm. because it mainly depends on outside warmth Mammals can improve insulation to reduce heat loss. This insulation can be fur or feathers or body fat. In the winter, many mammals will increase this insulation. Examine the graphic showing how hair interacts with the outside temperature. 9. What happens to the temperature of the air as it passes through the layers of skin (epidermis)? it decreases Animals can also alter blood circulation to reduce the amount of warm blood that comes close to the skin in contact with cold air. This graphic shows an Eskimo dog in an environmental temperature of -30°C. Temperatures are recorded at different parts of the body. 10. Which areas of the dog’s body are the coldest? nose and paws FINAL SYNTHESIS CLAIM EVIDENCE REASONING (apply scientific principles) Mammals use a variety of strategies to maintain homeostasis. The graphs the graphs show the tempatures that help show the wayhomeostasis works www.biologycorner.com