Principle objective of this lecture is to presentation on Genetic Control of Protein Structure and its functions. Genetic material of living organisms is either DNA or RNA. DNA: Deoxyribonucleic acid and RNA: Ribonucleic acid. Here explain Genes are lengths of DNA that code for particular proteins and both DNA and RNA are polynucleotides and they are made up of smaller molecules called nucleotides. Finally briefly analysis Structure of a nucleotide, Sugar phosphate bonds, Nature of the Genetic Material and Drosophila chromosome with examples and pictures.