Question

Which of the following has no teeth?
A. Crocodile
B. Birds
C. Whale
D. Bat

Answer 1

Teeth are the structures that are present inside the mouth. They are used for chewing, biting, and cutting food. They are made up of two parts namely the enamel and dentine. They have very less organic part due to which they do not degrade in the soil.

Complete answer: Let us look at all the options that are given to us one by one-
-Crocodiles are the members of the class Reptilia, and phylum Chordata. Crocodiles are very large land and water-dwelling organisms. They are carnivorous. Due to this, they have many teeth over the whole of their mouth. The total number of teeth in a crocodile is 80. Moreover, crocodiles are polyphyodont, i.e., their teeth grow several times during their lifetime.
-Birds are a member of the class Aves. These are aerial creatures. As they spend most of their time in the sky, so due to this reason there are several flight modifications in their bodies. One such adaptation is the modification of the mouth into a beak. They do not have any teeth. The beak helps in picking up and ingesting the food.
-Whales belong to the class Mammals of phylum Chordata. Whales are usually of two kinds, toothed whales, and baleen whales. As the name suggests toothed whales have teeth. However, their teeth emerge only once in a lifetime.
-Bats belong to the class Mammals of phylum Chordata. Just like all mammals, bats also have a well-developed set of teeth. They have incisors, canines, premolars, and molars in their mouth. The canines of a bat are usually known as the fangs.
Thus, based on the above information we can conclude that birds have no teeth.
Hence, the correct answer is option (B).

Note: Baleen whales do not have teeth. Instead, they have plate-like structures in their mouth which are known as the baleen plates. These plates hang from the roof of the inside of the whale’s mouth like a comb. Together they form a filter-feeding system. First, the whale takes in the water and then drains it out. This causes the food to get trapped in the baleen.