Elastin is a structural protein that is similar to that of:

Elastin is a highly elastic protein that is a key component of connective tissue in the body, particularly found in structures like skin, lungs, and blood vessels. Its primary role is to provide elasticity and resilience, allowing tissues to stretch and return to their original shape.

The correct answer draws a parallel between elastin and rubber in terms of their mechanical properties. Both elastin and rubber exhibit significant elasticity, meaning they can be stretched and compressed and then return to their original dimensions without permanent deformation. This property is crucial for the functionality of tissues that experience dynamic movements and need to withstand various mechanical stresses.

In contrast, options like plastic, mesh, and Silly Putty do not reflect the same elastic characteristics inherent to elastin. While plastics are generally rigid and can vary in flexibility, mesh materials are often more stable and don't possess the same degree of stretchability. Silly Putty, while somewhat elastic, does not exhibit the same structural properties and biological significance as elastin does within the body's connective tissues. Therefore, the comparison to rubber is most accurate in capturing the essence of elastin's functional characteristics.