See last lecture's topic dealing with the independent assortment of chromosomes. Pedigrees depict family relationships and indicate which ones have a particular trait. They can reveal the mode of inheritance of a particular trait. Dentinogenesis imperfecta and what it is . Fingernails and sometimes kneecaps or elgows do not deveolop properly because of a problem with the synthesis, assembly, or degradation of collagen, a protein that makes up connective tissue.
Affected people lack a critical enzyme that repairs DNA damaged by ultrafiolet light.
This results in rapid and severe sunburn and skin cancer.