Final answer:
Elasticity refers to the hair's ability to stretch and return to its original form, similar to certain properties of muscle tissue and various materials.
Step-by-step explanation:
The ability of the hair to stretch and return to its original length without breaking is referred to as elasticity. Elasticity is a property observed in various materials, including hair, where it indicates the capability of hair fibers to elongate under force and then retract to their original form once the force is removed. This quality is similar to how elastic fibers in muscle tissue allow it to recoil back after being stretched.
Materials exhibit elasticity up to a certain point, known as the elastic limit. Beyond this point, if the material is overstretched, it may not return to its original shape, a phenomenon known as plastic deformation. Hair care practices often aim to maintain hair elasticity since it is a sign of healthy, resilient hair.