Classical genetics color, flower color and seed shape. Mendel took peas that had differing phenotypic characteristics and test-crossed them to assess how the parental plants passed the traits down to their offspring. He started by crossing a round, yellow and round, green pea and observed the resulting phenotypes. The results of this experiment allowed him to see which of these two traits was dominant and which was recessive based upon the number of offspring with each phenotype. Mendel then chose to further his experiments by crossing a pea plant homozygous dominant for round and yellow phenotypes with a pea plant that was
Johann Karl Nestler stock animals and their offspring Nestler hoped to explain the (genetic history). Examination of the records of the ancestors of the best breeding animals, called by Nestler "developmental history" () was for him the reverse side of the same coin. According to Wood and Orel the search for rules of heredity in sheep created an atmosphere of enquiry about heredity in general, which had influence on later work of Gregor Johann Mendel, himself a student at the Faculty of Philosophy in 1840–43. Nestler was also a very active member of the "Moravian-Silesian Society for Advancement of Agriculture" (, in which