What advantage does giving birth in the harshest part of winter give to the grey seal pups?

The grey seals are found in the shores of the Atlantic Ocean. They breed in several colonies on and near the coast. They exhibit coloration of blackish to whitish specks. The males are darker in skin color than in females. The pups are born with yellow and white tint. A thick layer of skin called as blubber develops around the skin of the new ones which helps in providing them with insulation against the cold atmosphere.

tissue

explanation:

it is actually formed by geoup of cells which is tissue