Which of the following is not a respiratory organ in a rabbit?

The given figure shows the human respiratory system with structures labeled $A, B, C,$ and $D$. Which of the following options correctly identifies the structure and its main function or characteristic?

Cornea transplant in humans is almost never rejected. This is because

Which of the following is a very unique feature of the mammalian body?

The thoracic chamber is formed of ........

$A$ thin-elastic cartilaginous flap which prevents the entry of food into the larynx is known as