Question

The animal which lives in the polar region is
A. Nightingale
B. Frog
C. Polar bear
D. Fish

Answer 1

The absolute size of an animal and the relative proportions of various body parts is somewhat dependent on temperature. Generally it is found that birds and mammals attain greater body size in cold regions than in warm areas. But poikilotherms are smaller in cold regions. This is Bargeman's rule. In cold climates small animals lose their body heat very fast because they have larger surface area relative to their volume.

Complete answer:
There are a variety of adaptations which help organisms to survive the habitat where they live. Some of the adaptations are discussed below:
According to the Allen’s Rule, the mammals living in colder climates generally have shorter ears and limbs to minimise heat loss. The polar seas aquatic mammals have a thick layer of fat (blubber) below their skin that acts as an insulator and reduces loss of body heat.
The most important physical factors of the environment to which the organisms are adapted in various ways includes temperature, light, water and soil are. Homeostasis is the process of maintaining a constant internal environment by the organisms. It contributes to optimal performance of an organism.
One of the largest land carnivores which are found in the arctic sea are polar bears. They are highly adapted to live in cold habitats. For feeling warmth they have thick fur on their body which covers their feet. The buoyancy and insulation is provided by a thick layer of blubber beneath their fur. Also the narrow skull and long neck helps in streamlining them in water and warming the air that they breathe. They have their front feet which are large and flat which makes them excellent swimmers.
On the other hand, nightingale, frog and fishes do not have any adaptations to survive the extreme cold climate. Hence, the animal which lives in the polar region is the polar bear.

So, the correct option is option (C) Polar bear.

Note: Some organisms are regulators which are capable of homeostasis in the face of changing external environments. Others either partially regulate their internal environment which are called conform. Other species for avoiding unfavourable conditions have evolved adaptations in space called migration or in time aestivation, hibernation, and diapause.