Another Quick Question!!

[kc261]

It sounds like you are still not understanding some of the very basic stuff, and just like building a building, if you are trying to build knowledge on a base that is not solid, you'll end up with problems. I'll go over it quickly, which is not expected to teach you everything, but it should help you figure out where the holes in your knowledge are.

Genes come in pairs. Animals inherit those genes from their parents, one from each pair comes from the mother, and one from the father. Since the mother and father both had pairs, it is random which one of the 2 genes is passed on, so the offspring has a 50/50 chance at each one.

When an animal has a matched pair of genes, this is called homozygous. A homozygous parent will always pass the same thing on to their offspring, because no matter which gene is randomly selected, it is the same. There is still a 50/50 chance, but it is like flipping a penny and asking whether or not a copper colored side is up. It will always be copper.

When an animal has an unmatched pair of genes, this is called heterozygous. Again it is random which is passed on, but since they are different, there is a 50/50 chance which one will be inherited.

Remember that animals have THOUSANDS of different gene pairs. Each pair is called a locus. Some people find it easy to picture this like 2 rows of houses facing each other on a street. That is why we can have combo morphs. A pewter is a cinnamon pastel. A bumblebee is a spider pastel. That means at one locus (or the first pair of houses on the street), the pewter snake has one normal and one cinnamon, while the bee has 2 normals. At another locus (the next pair of houses on the street), the pewter has 2 normals and the bee has 1 normal and one spider. At a third locus, both of these snakes have one pastel and one normal. However, it is possible one has the pastel on the right side of the street, while the other has it on the left. That part doesn't matter. This is why when you do Punnett squares, it doesn't matter if you write aA or Aa, both will display the same trait or lack thereof. This is also why in any pairing, it does not matter which is the female and which is the male, as far as what offspring you'll get in that clutch. (Sometimes it will matter for making future pairings work out right).

Another thing you need to understand is that there isn't 1 normal gene. For every locus, there is a normal gene, and they are all different from each other. Again, this is why we can have combo morphs. Otherwise, a snake would either be normal or it wouldn't. But it can be normal at one locus, but a morph at a different locus.

Now, as far as dominant, co-dom, and recessive. First of all, in this post I'm going to explain co-dom the way it is used in BPs, which is not exactly the same as biology textbooks. A dominant gene will be expressed whether the animal is het or homo for that gene, and it will be expressed in the same way so you can't tell the difference. A co-dom gene will be expressed whether the animal is het or homo for that gene, but it will be expressed differently, so you can visually see if the animal is het (for example pastel) or homo (for example super pastel). Recessive genes are only expressed if the animal is homo for that gene. An animal that is het for a recessive is not visually distinguishable from an animal that does not carry the recessive gene at all.

Please note that recessive and dominant are the opposite of each other. This is because genes are recessive, dominant, or even co-dominant only in respect to each other. It is possible to have a gene that is recessive to one gene, but dominant or co-dominant to a different one, all on the same locus. Let's use albino as an example. We call albino a recessive gene because it is recessive in respect to normal. It is just as accurate to say that normal is dominant to albino. On a different locus, pinstripe is dominant to normal, and normal is recessive to pinstripe. Again, note that the normal gene that is dominant to albino is a totally different gene than the normal gene that is recessive to pinstripe.

I hope that clears up some things for you.

To answer some of the specific questions you asked in your last post:

There are homozygous forms of every morph. The question is whether or not those forms are visually different than the het form. For recessive, it is different, because the homo form is the only visual form. For dominant, it is the same as the het form. It is even possible that the homozygous form of some morphs is lethal, and depending on how & why it is lethal, it could happen very early in development so we'd never see anything other than slug eggs, if that. But just because we never see it does not mean it does not exist.

When you breed 2 different recessives... assuming they are visual (homo), you get an animal that is het for both of those traits. You could breed them together and have a chance at a double morph, which in your example would be an albino pied. This is because the 2 different morphs are located at different loci (locuses?). If the 2 different morphs did happen to be on the same locus, then you have to find out which of those 2 genes is dominant to the other one, or perhaps they'd be co-dominant to each other.

Recessive (visual or homo) to a het co-dom is exactly the same question you started this thread with. It is a homo to a het. 50/50 chance. The only question is 50/50 of what & what? You should be able to work this out easily by now. The visual recessive parent gives 1 gene to every offspring, so every offspring will be het for that recessive trait. The co-dom gives a normal to half the offspring, and a morph gene to half the offspring. So in your example, the offspring have a 50% chance of being enchi het for clown, and a 50% chance of being normal het for clown.

Recessive (visual or homo) to a homo (super) co-dom should also be easy to figure out once you've done the above step. In fact, it is even easier. Both parents give 1 gene to every offspring. There are no hets involved, so there are no 50/50 chances. Every offspring will be enchi het for clown.