Question

What are cold-blooded and warm-blooded animals?

Answer 1

Hint: Animals are classified as cold blooded (poikilotherm) or warm blooded (homeotherm) depending upon the presence of their ability to maintain body heat.

Complete answer:
Based on the ability to maintain the body temperature, vertebrates are divided into two groups: Poikilotherms and Homeotherms.

Homeotherms can carry out thermoregulation and they maintain a constant body temperature. These animals are commonly called warm -blooded animals. Birds and mammals constitute this group of vertebrates. Warm blooded animals burn fats to release energy in the form of heat and their body temperature is independent of any external factor.

To understand, let’s consider the example of humans, we have adaptations for this. If the outside temperature is high, we begin to sweat and bring about a cooling effect. When it gets cold, we reduce the blood supply to skin so less heat is radiated outside. At the same time, erector muscles make hair erect which we call ‘Gooseflesh’.

Poikilotherms cannot maintain their body temperature on their own and it changes as per the outside temperature but up to certain limits. These animals are commonly called cold blooded animals. These animals cannot survive extreme climatic changes and are thought to be primitive in the line of evolution. These animals cannot generate heat of their own and usually need to find places where they can maintain their body temperature by taking heat from or dissipating heat to the surrounding environment. Otherwise, their metabolic activities cease and they may die.

Poikilotherms undergo long sleep in order to avoid extreme conditions. Some of them undergo hibernation (winter sleep) while some of them undergo aestivation (summer sleep). Examples include reptiles, amphibians, pisces etc.

Note: Homeotherms are warm-blooded animals and Poikilotherms are cold-blooded animals. Homeotherms can generate body heat while the poikilotherms cannot maintain body heat of their own and they are quite affected by the surrounding temperature.