| A | B |
|---|
| anagen phase | initial growth phase during which the hair follicle actively produces hair |
| catagen phase | transition stage between the anagen and telogen phases of hair growth |
| cortex | main body of the hair shaft |
| cuticle | scale structure covering the exterior of the hair |
| follicular tag | translucent piece of tissue surroundÂing the hair's shaft near the root that contains the richest source of DNA associated with hair |
| macromolecule | molecule with a high molecular mass |
| manufactured fibers | fibers derived from either natural or synthetic polymers |
| medulla | cellular column running through the center of the hair |
| mitochondrial DNA | DNA present in small structures (mitochondria) outside the nucleus of a cell |
| molecule | Two or more atoms held together by chemical bonds |
| monomer | basic unit of structure from which a polymer is constructed |
| natural fibers | fibers derived entirely from animal or plant sources |
| nuclear DNA | DNA that is present in the nucleus of a cell and is inherited from both parents |
| polymer | substance composed of a large number of atoms that are usually arranged in repeating units |
| telogen phase | final growth phase in which hair naturally falls out of the skin |
| hair follicle | organ of the skin from which hair grows |
| keratin | hardened protein that forms hair and nail of mammals |
| nail polish | used to form a cast of cuticle of hair |
| continuous medulla | medulla runs the full length of hair shaft |
| interrupted medulla | medulla has a few breaks as it runs up the shaft of hair |
| fragmented medulla | medulla with many large breaks as it runs up the shaft of hair |
| bulb or flame shaped hair root | characteristic of hair root in anagen phase |
| elongated hair root | characteristic of hair root in catagen phase |
| flattened hair root | characteristic of hair root in telogen phase |
