Question

The wishbone of the birds is derived from?
a. Skull
b. Pectoral girdle
c. Pelvic girdle
d. Hindlimb

Answer 1

Hint: Wishbone is a bone found in birds in a forked manner. It is formed by the fusion of two clavicles. It is also found in some species of dinosaurs. It is present in the thoracic cavity and found near the collar bones.

Complete answer:
The wishbone of the birds cannot be found in the skull as it is formed by the clavicle known as the collar bone that serves as a connection between the shoulder blade and the sternum. There is no role of the skull in making a wishbone. Hence, it is an incorrect choice.

The wishbone of birds is formed by the fusion of two clavicles, the collarbones in the midline. So, the shoulder blades, coracoids and the clavicles together help in the formation of a wishbone. As these three types of bones only help in making of pectoral girdle. The wishbone is present in the thoracic cavity and hence pectoral girdle makes up the wishbone. This statement is correct.

Pelvic girdle formed by the three paired bones named as ilia, ischia, and pubes together. It is the hip bones made in a ring and connect in the pelvic region of spine to the lower limbs. So, it is not a correct answer. Hindlimb is the back limb of an animal. It helps in jumping high and catching prey.

Hence, the correct answer is option (B).

Additional information:
Wishbone is also known as furcula. It is fused with the chest bone. It is also attached with a strong, stiff tendon. They protect the chest cavity during the flight and help the bird to maintain its body shape. This ensures that the muscular contractions of flight do not break or collapse its lungs.

Note: Wishbone forms the dermal part of the girdle and has two collar bones joined by midline. It is present in the thoracic activity. It is the forked bone that helps in strengthening the thoracic cavity to withstand the flight.