Question

artic fox grows a white coat in winter and a brown coat in summer give reason

Answer 1

A pigment called melanin, absent in white fur, gives the fox its brown summer coat. The hair shafts of white fur are hollow, trapping warm air from the animal's body heat and acting as insulation much the same way as a down coat does for a human wearer.

Answer 2

Over the winter the arctic fox has a heavy white coat, but when early summer temperatures begin to melt the snow cover, the coat is shed for a thinner, two-tone brown pelage. A pigment called melanin, absent in white fur, gives the fox its brown summer coat.