Reptile & Amphibian Forums

I thought I had known better about these things, but after seeing a few advertisements, I feel as though my knowledge on genetics is contradictory.

What would the Percentage Hets be for the offspring of the following...

100% Het x Normal = ??
100% Het x 100% Het = ??
Homozygous x Normal = ??
Homozygous x 0 Het = ??

What are the parents of a 50% Het baby??
And what are the parents of a 66% Het baby??

Thanks in advance.
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Cheers!
• Chelsea Lynn Gardiner
(and Frank M. Wood)

That last one is:
Homozygous x One Hundred Percent Het = ??

I don't know why it replaces that character. Maybe its just my computer??
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Cheers!
• Chelsea Lynn Gardiner
(and Frank M. Wood)

Ill take a stab at it.

100% Het x Normal = 50% pos het 50% Normal

100% x 100% Hey = Some homo (not sure if it is 33% or not) and
66%het i beleive.

Homo x Normal = 100% Hets

Homo x het = Some homo and some 100% het

Now im not exactly sure this is correct but im pretty sure.
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B Sleeper

1.0 Chocolate Lab
0.1 ?? Normal Ball python (yet different)
1.0 04 Het Albino
1.1 06 Het Albino
1.0 06 Het Pied
1.0 06 Pastel
1.0 07 Pastel

the ones that have less than 100% should be possible het not het sorry bout that. I think im right im sure if not someone will correct me.
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B Sleeper

1.0 Chocolate Lab
0.1 ?? Normal Ball python (yet different)
1.0 04 Het Albino
1.1 06 Het Albino
1.0 06 Het Pied
1.0 06 Pastel
1.0 07 Pastel

If the gene is simple recessive, which I believe your question implies:

100% Het x Normal = Offspring will all look normal however any one selected from the clutch will have a 50% chance of being Heterozygous for the desired condition.

100% Het x 100% Het = 25% of the offspring produced will be the Homozygous(visible) condition. The rest will all look normal except any one offspring selected from the remaing normal looking babies will have a 66% chance of being Heterozygous for the condition.

Homozygous x Normal = All offspring will look normal and all offspring will be 100% heterozygous for the desired condition.

Homozygous x 100% Het = 50% of the offspring produced will have the Homozygous(visible) condition and the rest will be normal looking 100% Heterozygous offspring.

What are the parents of a 50% Het baby? One parent was a Het and one was Normal.

And what are the parents of a 66% Het baby? Both parents were Hets.

I hope this does not confuse you more 8(

Brad Ratliff
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Brad Ratliff
Ratliff Reptiles
Email

No, that didn't confuse me at all. That was perfect. I probably should have thrown in that I was talking about simple recessive gene, LoL. I just wanted to make sure what I thought the percentage offspring would be was correct or not. A friend of mine was arguing with me about it. Thanks for the help!!!
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Cheers!
• Chelsea Lynn Gardiner
(and Frank M. Wood)

hey Chelsea and Frank,

To add to Brads answer, on the 100% het to 100% het, the normal looking three are called 66% until they are bred. If you breed a homozygous to them and get visual then they are 100%, if you don't get any visuals then they are normals (but I wouldn't give up after just one try).

Cheers to you too

Rich
Chesapeake Bay Ball Pythons

100%het x normal = all babies will appear normal and have a 50%
probability of being het

100%het x 100%het = statistically 25% homozygous
25% normal
50% het
since there is no visual difference between the
normals and the hets, each is considered as
having a 66% possibility of being het

Homozygous x normal = all babies are 100%het

Since Brad Ratliff answered your question for a recessive mutant gene, I'll do dominant and codominant mutant genes.

By the way, het and 100% probability het are identical.

Codominant mutant gene:

>100% Het x Normal = ??

1/2 het, 1/2 homozygous normal

>100% Het x 100% Het = ??

1/4 homozygous mutant, 2/4 het, 1/4 homozygous normal

>Homozygous x Normal = ??

all het

>Homozygous x het = ??

1/2 homozygous mutant, 1/2 het

>What are the parents of a 50% Het baby??
>And what are the parents of a 66% Het baby??

No such animals. With a codominant mutant gene, you can tell the genotype from the animal's appearance.

Dominant mutant gene:

>100% Het x Normal = ??

1/2 het, 1/2 homozygous normal

>100% Het x 100% Het = ??

1/4 homozygous mutant, 2/4 het, 1/4 homozygous normal. As the hets and homozygous mutants look alike, these could be called 66% probability hets or 33% probability homozygous mutant.

>Homozygous x Normal = ??

all het

>Homozygous x Het = ??

1/2 homozygous mutant, 1/2 het. As the hets and homozygous mutants look alike, these could be called 50% probability hets or 50% probability homozygous mutant.

>What are the parents of a 50% Het baby??

Homozygous mutant x het

>And what are the parents of a 66% Het baby??

Het x het.

Note that the results for a dominant mutant gene are the mirror image of the results for a recessive mutant gene.

Paul Hollander