Gregor Mendel of Mendelian inheritance. Mendel worked with seven characteristics of pea plants: plant height, pod shape and color, seed shape and color, and flower position and color. Taking seed color as an example, Mendel showed that when a true-breeding yellow pea and a true-breeding green pea were cross-bred their offspring always produced yellow seeds. However, in the next generation, the green peas reappeared at a ratio of 1 green to 3 yellow. To explain this phenomenon, Mendel coined the terms “recessive” and “dominant” in reference to certain traits. (In the preceding example, the green trait, which seems to have vanished in
Classical genetics as molecular genetics. At the base of classical genetics is the concept of a gene, the hereditary factor tied to a particular simple feature (or character). The set of genes for one or more characters possessed by an individual is the genotype. A diploid individual often has two alleles for the determination of a character. Classical genetics is the part of genetics that is solely about the method in which genetic traits are transmitted via the acts of reproduction. Genetics is, generally, the study of genes, genetic variation, and heredity. The process by which characteristics are passed down from parents