Tongue : It is a freely movable muscular organ attached to the floor of the oral cavity. The tongue is covered with moist, pink tissue called mucosa. Tiny bumps called papillae give the tongue its rough texture. Thousands of taste buds cover the surfaces of the papillae. Taste buds are collections of nerve-like cells that connect to nerves running into the brain.
The tongue is is attached to the floor of the oral cavity by the frenum. Tongue is vital for chewing and swallowing food, as well as for speech.
Diphyodont is the condition of having two set of teeth during the life of an organism. For example : humans are diphyodont as they have two set of teeth namely temporary milk or deciduous teeth which are replaced by permanent or adult teeth.