In studies of human MZ and DZ twin pairs of the same sex who are reared together, the following concordance values are identified for various traits. Based on the values shown, describe the relative importance of genes versus the influence of environmental factors for each trait. Trait Concordance MZ DZ _ Blood type 100 65 Chicken pox   89 87 Bipolar disorder   67 13 Schizophrenia   72 12 Diabetes   62 15 Cleft lip   51   6 Club foot   40   4