Compare the structure and lifestyle of a seal and a whale. What are their similarities and differences?

Seals are well adapted to cold climates and aquatic life. They live in the water, but go ashore to rest. Their body is streamlined, smooth. The neck is practically undeveloped. The limbs are represented by flippers and perform well their function of swimming: the front ones are like oars, and the rear ones are like a rudder. They feed on fish. Cetaceans live only in water, do not go to land. For swimming, they have a tail fin and forelimbs in the form of fins. Both animals can find prey and communicate using ultrasound.