Deoxyribonucleic acid, DNA for short, is an organic compound with complex molecular structure. It exists in the nucleus as a component of chromosome. The function is to store genetic information. DNA molecules are huge and consist of nucleotides. The nitrogenous bases of nucleotides are adenine, guanine, cytosine and thymine; Pentose is deoxyribose.
DNA is sometimes referred to as “genetic particles” because during reproduction, parents replicate half of their own DNA to their offspring, thereby completing the transmission of traits. The chromosome of a prokaryotic cell is a long DNA molecule. Eukaryotic nuclei contain more than one chromosome and each chromatid contains only one DNA molecule. However, they are generally larger than DNA molecules in prokaryotic cells and bind to proteins.