the principles of heredity proposed by Gregor Johann Mendel (1822 — 84), Austrian monk and bota-nist, on the basis of his researches on hybridization of peas to explain the behaviour of factors (now called genes) that govern the transmission of inherited characters from generation to generation. On the basis of modern knowledge, Mendel's first law, the
law of segregation, states that every somatic cell carries a pair of allelic genes for each character and that the two genes in each pair separate during meiosis so that each gamete carries only one gene from each pair. Mendel's second law, the
law of independent assortment, states that the separation of members of any pair of allelic genes occurs independently of every other pair provided they are not linked.