
Answer:
In homeothermic (“warm-blooded”) animals, body temperature is carefully Â
regulated. The hypothalamus, located in the brain, acts as the master ther-
mostat to keep body temperature constant to within a fraction of a degree Â
Celsius in a healthy animal. If the body temperature starts to deviate much Â
from the desired constant level, the hypothalamus causes changes in blood Â
flow and initiates other processes, such as shivering or perspiration, to bring Â
the temperature back to normal. What evolutionary advantage does a con-
stant body temperature give the homeotherms (e.g., birds and mammals) Â
over the poikilotherms (e.g., reptiles and insects), whose body temperatures Â
are not kept constant? What are the disadvantages?
Explanation: Basic chemical understanding as revealed upwards Â