Multiple choice general knowledge science & technology _____ is the name of the protein, our hair is made up of Calcium Keratinine Iron Serotonin Reveal answer Fill a bubble to check yourself B Correct answer Explanation Hair is primarily composed of keratin, a fibrous structural protein that provides strength and protection to hair cells. The other options are not proteins found in hair - calcium and iron are minerals, while serotonin is a neurotransmitter.