Applied genetics is the manipulation of the hereditary characteristics of an organism to improve or create specific traits in offspring. Controlled breeding involves manipulating the hereditary characteristics of offspring by selection parents with specific phenotypic traits. Applying controlled breeding to plants and animals has traditionally been based upon three techniques: mass selection, inbreeding, and hybridization. In hybridization two different but related species or varieties of plants or animals are crossed. The products of this type of crossbreeding are called hybrids. Breeders can also introduce desirable traits into a species by inducing polyploidy, a conditioning which cells contain multiple, complete sets of chromosomes. Gene splicing is the process by which a gene from one organism is placed into the DNA of another organism. Genetic engineering frequently involves the use of recombinant DNA, which is composed of DNA segments from at least two differing organisms. Genetic engineering has many commercial applications. The present book provides a detailed introduction to the basic genetic principles and presents the molecular aspects and latest applied areas in genetics. The simple and lucid presentation of complicated topics in basic genetics, molecular genetics, medical genetics and in the latest applied areas of genetics would prove to be very useful to students, researchers and teachers alike.