Question

All of the following are characteristics of amphibians except that they:

• A. Are usually tetrapods
• B. Undergo metamorphosis
• C. Have a 3-chambered heart
• D. Have gills in adults

Answer 1

The correct option is D Have gills in adults

Amphibians are ectothermic, tetrapod vertebrates belonging to the class Amphibia. Frog is an organism of the class Amphibia. In frog development, the eggs hatch and give rise to tadpoles, small aquatic larvae that have external gills.Amphibians have a 3-chambered heart, which provides some separation of blood coming from the lungs and blood coming from the body. When a frog is out of the water, mucus glands in the skin keep the frog moist, which helps absorb dissolved oxygen from the air. A frog may also breathe much like a human, by taking in air through their nostrils and down into their lungs and not through gills.

So, the correct option is 'D'.