Select the animal having venous heart.

Reptiles are known for having three chambered heart. Which animal shows a near four chambered condition in reptiles?

The circulatory system has evolved from open to closed type in Animal kingdom. Which Phylum can be called first to represents closed circulation?

Pinna is part of external ear and it is found in mammals. Do aves and reptiles show external ear in any form?

Birds need to keep their body light to help in flying. Hence, they show presence of some organs only on one side. How their skeleton helps in reducing their weight?