Ideal knot. Computer artwork of a simple trefoil knot which can be used to mathematically model molecules of Deoxyribonucleic Acid (DNA). This kind of knot is said to be ideal" or "irreducible", being formed from the shortest possible tube of constant diameter. It is also an "independent" knot as it is not comprised of simpler knots. Ideal knots have interesting features, including a direct relationship with the time-averaged shapes of DNA molecules in solution. DNA encodes an organism's hereditary characteristics."