Which statement about hair is true?

Which statement about hair is true?

• A. Myosin
• B. Elastin
• C. Collagen
• D. Keratin

Answer: (D)

Hair is primarily made of keratin, a tough structural protein that forms hard keratin in the hair shaft. Keratinocytes in the hair follicle produce keratin and then keratinize as they move upward, creating a keratin-rich, keratinized shaft. The strong, rigid keratin fibers are reinforced by disulfide bonds, which gives hair its durability and shape. This distinguishes it from the other proteins listed: myosin is a motor protein in muscles, elastin provides elasticity in connective tissue, and collagen provides tensile strength in skin and other tissues. Keratin best describes the protein that makes up hair.

Hair is primarily made of keratin, a tough structural protein that forms hard keratin in the hair shaft. Keratinocytes in the hair follicle produce keratin and then keratinize as they move upward, creating a keratin-rich, keratinized shaft. The strong, rigid keratin fibers are reinforced by disulfide bonds, which gives hair its durability and shape. This distinguishes it from the other proteins listed: myosin is a motor protein in muscles, elastin provides elasticity in connective tissue, and collagen provides tensile strength in skin and other tissues. Keratin best describes the protein that makes up hair.