Question

Which among the following have scales?
(i) Amphibians
(ii) Pisces
(iii) Reptiles
(iv) Mammals
A. (i) and (ii)
B. (iii) and (iv)
C. (ii) and (iii)
D. (i) and (ii)

Answer 1

Hint:-Some animals have scales on their body which help them in respiration and movement. Pisces includes bony fishes. It has cycloid scales. Reptiles have special features on their body to help them from dehydration. Amphibians show cutaneous respiration. Mammals have hairs on their skin.

Complete Answer:-
Phylum chordata includes vertebrates in which the notochord develops into a vertebrae column. Amphibians, pisces, reptiles, mammals all are classified in this group. Amphi means dual so they have dual habitat. They can survive on both land and water. They need respiratory structure to survive in both habitats. They have moist skin which is also used for respiration. It is called cutaneous respiration. Due to this scales are not present on the body of amphibians.
Pisces is a super class which includes true fishes. On the basis of endoskeleton two types of fishes are found in class: Bony fishes and cartilaginous fishes. They both have scales on their body. Bony fishes have cycloid scales while the cartilaginous fishes have placoid scales. Shark fish have modified scales.
Reptiles have dry or cornified skin. They have scales on their body. Some reptiles have hard protective scales on their skin. Reptiles have scales composed of keratin. Scales are the waterproof barrier of skin, which allow them to survive away from water without the threat of dehydration.
Mammals include human beings. The skin of the mammals has hair, fur and sweat glands. Mammary glands are also the modified sweat glands. They do not have scales on their skin.
From the above information we have found that both Pisces and Reptiles have scales on their body.
Thus, the right option is C.

Note:- Scales on the body of bony fishes have similar structure as teeth. It originates from the mesoderm. Most of the fishes have protective layers of mucus and slime. It protects against pathogens such as bacteria, fungi, and viruses. It also helps to reduce the surface resistance when the fish swims. Scales are mainly of four types: Placoid, Cosmoid, Ganoid, Cycloid and Ctenoid.