ABSTRACT
Mendel discovered the genetic segregation of simple traits using crosses of garden peas expressing different characteristics. This chapter discusses genetics basics relevant to genomics. These include: meiosis and recombination in cytogenetics, gene frequency and additive and dominant genetic effects in population and quantitative genetics and DNA sequence and gene expression in molecular genetics. Mendelian genetics is concerned with classical simple trait segregation theory and simple linkage genetics. Mendelian laws include the law of segregation and the law of independent assortment. For traits controlled by a single gene and having simple heredity, each somatic cell of an individual carries a pair of alleles. There are two regular types of cell division in biological development: mitosis and meiosis. Both genetic and cytological techniques have been used to study genetic recombination and chiasmata formation. Population genetics focuses on the frequencies, distribution and origins of genes in populations.
