What type of sternum is found in birds?

In which of the following animals,the digestive tract has additional chambers like crop and gizzard?

Students of class $XII$ were given a list of the following characters: clawed toes,curved beak,feathers,pneumatic bones,wings,and fur. In this list,how many are volant adaptations?

Only the right aortic arch is present in:

Which of the following is $NOT$ found in birds?

What is the primary function of pneumatic bones in birds?