When a chemical relaxer and heat applied to a curly hair, the protein present inside your hair get denature. Due to this denaturation of protein in the hair, the hair are soft and flexible which can be converted into any direction and different styles can be done. If chemical perm or relaxer is applied to straight hairs, it also denature the protein and make the hair curly.
Tissue typing is a screening process in which cell markers in a donated organ or tissue are identified so that they can be matched to a recipient with similar cell markers. This has become more important in recent years because of the number of organ transplants