briancady413 schreef
"Gene' is a catagory, of which alleles are members.
An allele is itself a type of chromosome sequence - two identical
sequences may be of the same allele. [...]
Regarding the alcohol dehydrogenase gene, we might have two identical
chromosome sequences of one of the two alleles, or one of each type.

+ + +
If they are identical they are the same allele.
Two alleles are by definition different from each other.
There can exist any number of alleles of a particular gene.
PvR

E.g.
http://en.wikipedia.org/wiki/Allele_frequency
http://www.informatics.jax.org/userd...ele_help.shtml