Two genes might be alleles, or they might not be alleles.
+ + +
No. You either have a bad book (not sure if they exist) or you read wrong.

Perhaps what he meant is that if you have two genes from different loci on the
chromosome, they are not alleles. Alleles are two different genes found in the
same location on different chromosomes, having a different effect on the same
trait, such as a gene for a normal pigment enzyme and a defective gene which
does not create that enzyme. When you breed a plant with the defective gene on
both sets of chromosomes, you get white flowers.
Iris,
Central NY, Zone 5a, Sunset Zone 40
"If we see light at the end of the tunnel, It's the light of the oncoming
train."
Robert Lowell (1917-1977)

Iris Cohen schreef
Perhaps what he meant is that if you have two genes from different loci on
the chromosome, they are not alleles. Alleles are two different genes found
in the same location on different chromosomes, having a different effect on
the same trait, such as a gene for a normal pigment enzyme and a defective
gene which does not create that enzyme. When you breed a plant with the
defective gene on both sets of chromosomes, you get white flowers.
Iris,

+ + +
I doubt he meant anything really.
Genes tend to have fixed positions (ie occur on a certain spot on a certain
chromosome), but this is no requirement. Also the fact that many different
genes can have an effect on a certain property does not make the discussion
easier. Alleles are the same gene, in another edition. Usually alleles are
found on the same chromosome (ie on a particular chromosome, not both on the
same copy of that particular chromosome), and as chromosomes come in pairs
there are usually two alleles present. But this is all very general:
pictures do help (a lot).
PvR

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

Iris Cohen wrote:
[b] Two genes might be alleles, or they might not be alleles. BRBR

I did not write any of that.
Iris,
Central NY, Zone 5a, Sunset Zone 40
"If we see light at the end of the tunnel, It's the light of the oncoming
train."
Robert Lowell (1917-1977)

Iris Cohen wrote:
[b] Two genes might be alleles, or they might not be alleles. , etc.

I did not write any of that.
Iris,
Central NY, Zone 5a, Sunset Zone 40
"If we see light at the end of the tunnel, It's the light of the oncoming
train."
Robert Lowell (1917-1977)

Iris Cohen wrote:
[b] Two genes might be alleles, or they might not be alleles. , etc.

I did not write any of that.
Iris,
Central NY, Zone 5a, Sunset Zone 40
"If we see light at the end of the tunnel, It's the light of the oncoming
train."
Robert Lowell (1917-1977)

Iris Cohen wrote:
[b] Two genes might be alleles, or they might not be alleles. , etc.

I did not write any of that.
Iris,
Central NY, Zone 5a, Sunset Zone 40
"If we see light at the end of the tunnel, It's the light of the oncoming
train."
Robert Lowell (1917-1977)

Iris Cohen wrote:
[b] Two genes might be alleles, or they might not be alleles. , etc.

I did not write any of that.
Iris,
Central NY, Zone 5a, Sunset Zone 40
"If we see light at the end of the tunnel, It's the light of the oncoming
train."
Robert Lowell (1917-1977)