- Thread starter
- #3,141
You are so lucky I have not left to see my new DW yet. My old DW needs to finish packing and the drug store is beings low getting us are drugs. And WHO could have a could trip without drugs?
Using JJ and Ethel as an example. they have 3 pairs that control their color. The 3 pairs are Bb Dd Rr. The upper case letter is dominant. I use the term "genes" with these. Technically that is wrong they are "alleles" Which is a part of the gene. When I tell you these things understand I am a lay person and not an expert, so CUT me some SLACK you purest out there.
The B controls Black
the D is the gene controlling the slate appearance
R is the red part.
JJ and Ethel are Bb Dd Rr SO they have a dominant and an submissive alleles for each of the three "genes" we care about for their color.
When they mate each one of them can pass on one alleles to their baby. So JJ gives the baby a "B" and Ethel gives him a "b". JJ gives a "D", Ethel a "d" and finally JJ gives a "r" and Ethel gives a "R".
So writing the offspring's "gene code" ( I coined that) it would be Bb Dd Rr this is identical to JJ and Ethel so we would have a rusty slate just like them.
Before we go on, know that all genes do not express or insert themselves equally.
Now the next offspring gets a different bunch of alleles from JJ and Ethel. Lets say JJ gives the baby "b" "D" "r" and Ethel gives it a "b" "D" "r".
The genetic make up would be " bb DD rr" That is Ginger, Has no gene for Dominant Black and has no dominant gene for Red. so you get that washed color he has and because he has a dominant gene for "slate" it is all washed out.. Hence Ginger.
Now which allele goes to the offspring is completely random and equal. JJ can give 50% of his offspring a B and 50% a b. Ethel the same. When you add put them together, the baby has a 25% chance of having "BB" and "bb". There is 50% chance of Bb. If the first letter comes from JJ and the second from Ethel it is 25% Bb and 25% bB. BUT the dominant gene is always written first, so Bb and bB are the same thing written as Bb. Did that make sense?
There is a thing called a Punnet Square . It is a graph with the Each parents "genes listed on the X and Y axis. I have put the B and b above each column
I cannot get the B and b to go vertically alongside the rows. So you have to put them there in your mind. But I think you get the idea of how the genes are passed to the babies. I wrote them as if the first letter in each box comes from the top bird and the second from the bird on the side. remember a Bb and a bB are identical.
B b
BB Bb
bB
bb
It is the same way the sex of the baby is passed.bB
bb
It is all random and when you think there is 3 pairs in JJ and Ethel it makes more combinations possible, We can do the same square for the D and the R.
All three are needed to give us the end result. Does this help?
