How do dolphins and whales breathe underwater?

• Sea animals like dolphins and whales do not have gills. They breathe in air through blowholes that are located on the upper part of their head. (1 Mark)
• This allows them to breathe in air when they swim near the surface of the water. Lungs then help in absorbing the oxygen from it. (1 Mark)
• They can stay inside water for a long time without breathing. They come out to the surface of the water, when they need to breathe in air from the atmosphere. (1 Mark)