Hair is mainly made of a protein that is called keratin. It is made of the same thing that nails are made of. The only difference is the difference in color due to the presence of Melanin. The color of the hair varies with the quantity of melanin present on each strand. Hair can be black, red, brown and chestnut in color. As we grow old, the pigment present in the follicles begins to disintegrate that results in gray or black hair.
You may wonder why you have curly hair. Well, the answer lies in genetics. Within the hair protein compound are sulfide atoms. When the sulfide atoms stay close together, they develop a bond called disulfide bonds. But if they are placed further from each other and yet form the disulfide bond, then these strong bonds will have a tendency to bend the protein, and thus it results in curly mane. If you want to perm it artificially then there are various chemicals and tools available. The perms alter the number of disulfide bonds present in the hair. However, chemically curled hair is not permanent. The part of hair that grows after you perm your hair will not have the curly effect. So you ill have to repeat the procedure after six months or so.