Question

Why ploikiothermic animal of arctic region have more unsaturated fats?

Answer 1

when the temperature is very low, the cell membranes of cold blooded(poikilothermic) animals would tend to form a solid gel like structure.

But if unsaturated fatty acids are present in the membrane, it helps to maintain a more random, fluid state at lower temperatures.

So, this actually prevents the freezing of poikilotherms from getting frozen at low temperatures