DNA black dots clip.  DNA is a molecule composed of two polynucleotide chains that coil around each other to form a double helix carrying genetic instructions for the growth and reproduction of all known organisms. You can think of DNA as a recipe book and the nucleotides as the letters that make up the words in the recipe.  Just as different combinations of letters form words, different combinations of nucleotides form genes.  And just as a recipe book has many recipes, a DNA molecule has many genes.  The DNA molecule is organized into structures called chromosomes, which are packaged in the nucleus of the cell. Polymime are one of the UK's top animation companies offering royalty free medical stock images and medical stock videos. Other services including 3D rending, interactive 3D, vfx and more.