title: A rational treatment of Mendelian genetics.
abstract: BACKGROUND
  The key to a rational treatment of elementary Mendelian genetics, specifically to an understanding of the origin of dominant and recessive traits, lies in the facts that: (1) alleles of genes encode polypeptides; (2) most polypeptides are catalysts, i.e. enzymes or translocators; (3) the molecular components of all traits in all cells are the products of systems of enzymes, i.e. of fluxing metabolic pathways; (4) any flux to the molecular components of a trait responds non-linearly (non-additively) to graded mutations in the activity of any one of the enzymes at a catalytic locus in a metabolic system; (5) as the flux responds to graded changes in the activity of an enzyme, the concentrations of the molecular components of a trait also change.
  
  
  CONCLUSIONS
  It is then possible to account rationally, and without misrepresenting Mendel, for: the origin of dominant and recessive traits; the occurrence of Mendel's 3(dominant):1(recessive) trait ratio; deviations from this ratio; the absence of dominant and recessive traits in some circumstances, the occurrence of a blending of traits in others; the frequent occurrence of pleiotropy and epistasis.
authors.affiliation: Department of Molecular and Cell Biology, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, Scotland, UK. j.w.porteous@abdn.ac.uk
authors.forename: John W
authors.initials: JW
authors.lastname: Porteous
mesh_terms: D005799:Genes, Dominant; D005808:Genes, Recessive; D006706:Homeostasis / Q000235:genetics*; D006801:Humans; D008660:Metabolism / Q000235:genetics*; D008957:Models, Genetic; D019655:Quantitative Trait, Heritable