ABSTRACT
The science of genetics relates to heredity and variation-continuity of the life. Cell division, mitosis and meiosis, and precise DNA replication predict the inheritance of a particular trait from parents to the progenies. A clear understanding of the mode of inheritance is revealed by the science of genetics and its foundation was laid by J. G. Mendel in 1865 based on experiments of the garden pea (Pisum sativum) (Appendix A). The selection of garden pea was a wise choice because: (1) it is a self-pollinated plant and pollination can be controlled and selng of F1 posed no problem; (2) it is easy to cultivate this plant and requires only a single growing season; (3) this plant has many distinguishing sharply dened inherited traits. However, Mendel’s laws were unrecognized until 1900 and this may be due to a number of special reasons (Strickberger, 1968): The variability among the F2 and further hybrid generations could be traced to the original variability in the rst parental cross. The factors that could be traced were followed but did not change during the period of observation but only expressed themselves in new and different combinations among the offspring.
