Which fibrous protein in the skin provides form and strength?

The correct answer is collagen. Collagen is a key structural protein found in the skin that plays a crucial role in providing form and strength. It is the most abundant protein in the body and is essential for maintaining skin elasticity and overall firmness. Collagen fibers create a supportive network that helps skin resist stretching and sagging, thereby contributing to its structural integrity over time.

While keratin is another important fibrous protein, it primarily serves to protect and create a barrier on the skin's surface, rather than offering structural support. Elastin is also a fibrous protein, but its main function is to allow tissues to return to their original shape after stretching, contributing to skin elasticity rather than strength. Melanin, on the other hand, is a pigment responsible for skin color and does not provide structural properties.