Class Amphibia - Characteristic Features MCQ - Practice Questions with Answers

• The animals belonging to this class live in water as larvae and on land as adults. They need water to complete their life cycles.
• They have a characteristic smooth and moist skin with many glands.
• Scales are absent from their body.
• Their body is divided into head and trunk. There is no neck.
• Out of two pairs of limbs, the forelimbs are smaller than hind limbs. The hindlimbs are muscular and help in jumping. They have webbed-feet that allow swimming.
• Their eyes are covered with movable lids called nictitating membrane.
• Tympanum is the hearing organ. There is no external ear.
• The respiratory organs include gills, lungs and skin.
• They are cold blooded.
• They have a three chambered heart. 
• They have separate sexes. Fertilization occurs externally in water.
• Development is indirect and involves metamorphosis
• Examples: Bufo (Toad), Rana (Frog), Hyla (Tree frog), Salamandra (Salamander), Ichthyophis (Limbless amphibia).

Classification of Class Amphibia:

The class Amphibia is classified as follows:

• Order Urodela : These are tailed amphibia. The two pairs of limbs are equal. For example, Salamandra.
• Order Anura : These are tailless amphibia. Tail and gills are present in larval stage. For example, frogs and toads.
• Order Apoda : Limbless amphibia. They are adapted for burrowing. They are also called blind worms because of non-functional eyes. For example, Ichthyophis.