Significance of Discoveries in Genetics and DNA Essay

Significance of Discoveries in Genetics and DNA - Essay Example The principles and procedures of genetics were first advanced by Gregory Mendel, who performed a series of experiments that pointed the existence of genes. Mendel performed experiments through selective cross breeding of pea plants over generations. He discovered that some traits show in offspring without any blending with parents. For example, an offspring of a cross-pollinated purple flowered and white coloured pea plant did not rise to intermediate colours. The offspring in the first generation were in a ratio of 3:1 and the second-generation self-cross gave rise to a 1:1 ratio. Mendel therefore concluded that inheritance of traits is determined by units that are passed to offspring unchanged. Secondly, that an individual will inherit one unit from each parent for each trait and that the trait does not show up in the first generation, but will eventually in the subsequent generations. According to Mendel, the dominant allele masked the presence of the recessive allele in the F1 generation. His work gave rise to two genetic principles. Firstly, the law of segregation that states that for any trait alleles separate, only one passes fr om the parent to the offspring. Secondly, the principle of independent assortment which states that alleles are passed from the parent to the offspring independent of each other (Bortz, 2014). Following the discovery of Mendelian principles, T.H. Morgan performed experiments on the fruit fly Drosophila melanogaster because of their different body features that can help distinguish males and females. He observed the colour of their eyes, shape of wings and body shape. The choice of characteristics was distinctive for crossing because of the pronounced phenotypes. Before Mendel’s discoveries, evolutionary scientists like Charles Darwin believed that traits in an organism are selected through natural selection where the fittest organisms survived phasing out the least adaptable species.