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Ok, I'm trying to understand genetics, and have a few questions.

Lets take hognoses for example.

What would be the possible outcomes for these pairings.

1. Albino hognose with a proven het hognose.

2. Albino hognose with an albino hognose

3. Albino hognose with a 66% chance het albino (turns out to be het)

4. Albino hognose with a 66% chance het albino (turns out not to be het)

Can somebody please explain?

Thanks.
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Albinism is a simple recessive trait, so in response to your questions:
1. Albino hognose with a proven het hognose.
>>>would yield both albinos, and (100%)het albinos ...approx
half are albinos, and half are hets (which would appear normal)
2. Albino hognose with an albino hognose
>>>a bunch of albino babies.
3. Albino hognose with a 66% chance het albino (turns out to be het)
>>>once it proves out, that 66% means nothing...it is het for albino. refer to question/answer #1
4. Albino hognose with a 66% chance het albino (turns out not to be het)
>>>again, once it proves...in this case, it boils down to
albino x normal = a clutch of (100%)hets.

To understand why, take a look at these examoles. As already stated, albinism is a simple recessive trait. I will indicate the trait with a lower case "a". normal with a capital "A".
A het for albino carries the trait but looks normal. It would therefore be represented as "Aa". A visible albino would be "aa". So for your scenario, albino x het would be calculated in a punnett square, as below

A a
a Aa aa In this case, half of the offspring are Aa
a Aa aa (hets) and half are aa (albino)

for albino x albino

a a
a aa aa All the offspring are aa (albino)
a aa aa

for albino x normal

A A
a Aa Aa All the offspring are Aa (hets)
a Aa Aa

The percent hets (66%, 50%) refers to the likelihood that a given offspring is carrying the recessive trait. the lower the number, the less likely it is that it will prove out. this is because if you are not working with obvious morphs, or 100% hets, things get a little more involved. for example:
het x normal

A a
A AA Aa half are normals, half are hets. you can't
A AA Aa tell them apart by looking at them, so they
are marketed as 50% hets.

A het X a het looks like this:

A a
A AA Aa In this case 1/4 are visual albino (aa), 1/4
a Aa aa are normal, and 2/4 are hets. take the visual
morphs out of the picture and you see that
2/3 are het...marketed as 66% het

Hope this helped

sorry about that - their darned left justification tore the heck out my explanation. hope you can still follow it

If you really want to learn genetics, you ought to get a genetics text, like "Schaum's Introduction to Genetics", by Elron and Stansfield. A used, PB copy of the latest edition (2002) costs under US$10. I like it because of the problem oriented format and low cost. I don't like herper genetics web pages because a great many have more or less serious omissions and misinformation. Texts aren't perfect either. But the marketplace weeds out the worst texts, while anything not libelous can stay on the net.

By the way, the other posts in this thread are correct. But those problems are just the beginning in genetics.

Good luck.

Paul Hollander

Could you provide an ISBN number for that text? They're found on the publishing info page at the front of the book. Thanks
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