Concept:The part labelled III is identified by studying the structure of a bird’s egg.
Explanation:A bird’s egg has distinct parts, each with a specific position and function.
The albumen is the clear white fluid that surrounds the yolk.
The chalaza is a twisted cord-like structure that keeps the yolk in the centre.
The air space is usually found at the broad end of the egg.
Label III points to the large, rounded, central mass of the egg.
That central mass is the yellow yolk, which serves as food for the developing embryo.
Answer:C. yolk
