1.1 DEFINITION AND SCOPE OF GENETICS
Genetics is the science of heredity. It is concerned with the behaviour of particulate ‘factor ‘ now called genes, which are passed from parent to their offspring in the reproductive process. genes are responsible for differences and similarities of various characters or traits among individuals. The term genetics was first suggested in 1906 by an experimental geneticist, William bateson. Among its different areas are mendelian molecular, quantitative and population genetics.
Mendelian genetics deals with simply inherited traits, that is, those governed by relatively few gene pair differences and whose transmission follows simple mendelian rules. These characters are also referred to as mendelian characters.
Most molecular traits, such as restriction fragment length polymorphism (RFLPS) are also inherited in a mendelian fashion. Like classical genetics, molecular nature and largely concerned with nature and transmission of genetics
Information and with the method of translation of this information into observable characters. Quantitative genetics on the other hand, is concerned with inheritance of quantitative characters. Unlike mendelian traits, these characters are governed by few or several genes of small effect, which cannot be individually identified by their segregation. Consequently, the methods of quantitative genetics are different from those of mendelian genetics. However, the genes governing quantitative characters obey the same laws of transmission as those governing quantitataive (mendelian ) characters . this means that quantitative genetics founded on menelian principles.