In 1953, James Watson and Francis Crick,

Came up with an image truly slick,

To represent a model of DNA,

That would truly blow the world away.

This was a beautiful double helix,

With small rungs that bound the two ribbons or ‘sticks’.

These rungs were the bases of a neucleotide,

But to pair these bases up seemed to be cockeyed,

Till they found that Thymine paired with Adonine,

Just as Guanine paired with Cytosine.

And if you set T opposite A, and G opposite C,

Each side was in exact complimentary symmetry.

Take a look, and judge these strands

This is the blueprint for your heart, your eyes, your hands.