Stewart Robert Hinsley wrote:
In message .com,
Raphanus writes

Different alleles are often, but not universally, of the same length. In
some cases they are distinguished by one or more base pair
substitutions. In others they are distinguished by the insertion or
deletion of lengths of DNA.

OK. Now in a heterozygous gene the two alleles would have to be of
the same length - right? Otherwise there would be a "kink" in one
strand of the DNA spiral (?). I appreciate your answers. They give me
much to "chew on."