Question

What are homeotherms? Give examples.

Answer 1

Hint: The animal like birds and mammals has a certain body temperature which helps in metabolic activities. Animals are divided into two categories on the basis of who can regulate their internal body temperature - poikilotherms and homeotherms.

Complete Answer:
- Homeotherms are warm blooded animals that maintain a stable internal body temperature regardless of external influence. These warm blood animals show thermoregulation. Thermoregulation is the process by which the body maintains its internal temperature.
Examples: mammals, birds, bats, pigeons and rabbits

- In summer, when outside temperature is more than body temperature (370$^\circ$C) we sweat profusely. This results in evaporative cooling and brings down body temperature. In winter, when the temperature is below 370$^\circ$C, shivering occurs. The skeletal muscle vibrates and produces heat and raises the body temperature.

- Thermoregulation is energetically expensive especially for small animals (shrews, humming birds etc.). They have a larger surface area relative to their volume. So they lose body heat very fast when it is cold outside. Then they have to expend a lot of energy to generate body heat. Therefore very small animals are rare in Polar Regions.

- The polar animals have a thick fatty (adipose tissues] layer under their skin called blubber. Adipose tissue has a low thermal conductivity, and thus it does not transfer heat as well as other tissues and materials—such as muscle or skin, thus, helping in insulating an animal's body.

Note: The importance of thermoregulation is as follows,
- It helps in controlling the loss or gain of heat.
- It helps in maintenance of an optimum temperature range of an organism.
- If the temperature of the body falls below 35$^\circ$Celsius then it may lead to brain damage, cardiac arrest, and maybe even death.