Question

Which of these animals has slimy scales on their body?
A. Reptiles
B. Birds
C. Fish
D. Pangolin

Answer 1

Hint: The scales are the outer covering present on certain animal bodies. The major function of these structures is to provide protection from the stress factors in the environment as well as in protecting themselves from the predators.

Complete answer:
The slimy scales are present on the body of fishes. These structures help in providing protection, as well as in reducing the turbulence provided by the water around. The scales on fishes are developed from the skin layer known as the epidermis. There are different kinds of scales such as the placoid, ctenoid, cycloid, or ganoid.
Considering the other given options:
Reptiles have scales produced from the dermis layer of skin. Unlike the smooth and slimy scales of reptiles, they have rough, pointed, and leathery scales. Thus it is not the appropriate option.
The epidermal scales of birds are developed into feathers in the course of evolution. Thus it is not an appropriate option.
Pangolin scales are composed of a protein known as keratin. It is hard and pointed. Thus it is not an appropriate option.
Therefore, from the options given above, the most appropriate option is C. Fishes possess slimy scales on their body.

Note: The placoid scales are spike-like and bony and have an enamel-like appearance. Ganoid scales have an appearance similar to that of placoid scales, but they are covered with a material known as ganoin. Cycloid scales round or oval in shape and are large and thin. Ctenoid cells are similar to cycloid scales but are overlapping. Cycloid and ctenoid scales are present in higher or advanced fishes.