There are only four letters
in the DNA code: A, T, C, and G, short
for adenine, thymine, cytosine, and guanine.
Just like in the analogy with the red
hat, one letter can be changed, deleted,
or added. In addition, entire pieces of
code (i.e., whole words and sentences)
can be spelled backwards, cut and pasted
where they don't belong, or cut short,
all of which can change the form and function
of the end protein product in the body.
