Some common human syndromes; Cell division; Prenatal development; The formation of the germ cells; Simple inheritance; Sex determination; Sex linked inheritance; Antigens and antibodies: the blood groups; The immune system; Mutation and gene expression; Locating genes in the genome; The basis for induced genetic change; Exposures of humans to radiation; The nuclear energy controversy; Chemical compounds causing genetic damage; Twinning; Behavior and intelligence; The sex ratio.