Dna
...has tremendously advanced. Genetics is the science in which we study about heredity; physical and chemical properties of hereditary material and transmission of this hereditary material from one generation to the next. Therefore, DNA (deoxyribonucleic acid) is a one of the most vital molecule of a living system. It carries the genetic information necessary for the organization and functioning of most living cells and control the inheritance of characteristics. It is the biochemical molecule that makes chromosomes and genes (Benjamin. 1994).
Structure of DNA
DNA basically consists of a chemically linked sequence of subunits. Each subunit contains a nitrogenous base (a heterocyclic ring of carbon and nitrogen base), a pentose sugar (a five-carbon sugar in ring form), and a phosphate group. The nitrogenous bases fall into the two types; purine and pyrimidine. Pyrimidines have a six-member ring while purines have a fused- five and six –members ring.
Each nucleic acid is has 4 basic types.. The same two purines, adenine and guanine, are present in both DNA and RNA. The two pyrimidines in DNA are cytosine and thymine. The bases are usually referred to by their initial letters; so DNA contains A, G, C and T. Two types of pentose are found in nucleic acids. They distinguish DNA and RNA and give rise to the general names for the two types of nucleic acids. However, in case of DNA, the pentose is 2-deoxyribose.
Where nucleotides provide the building blocks from which nucleic acids are constructed (Stanley and Freifelder. 1994). The nucleotides are linked together into a polynucleotide chain by a backbone consisting of an alternating series of sugar and phosphate residues. Therefore, DNA has 2 strands and these twin strands, in the form of a double helix. They are composed of successive units of the sugar de-oxyribose, phosphate and the bases adenine, cytosine,...
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