5 years, 4 months ago-
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I found a great video on how to determine the results of a cross between two traits. This is by using a Punnett’s Square. The Punnett’s Square is an essential tool for determining the purity of your fowl, and determining the result of a mating with two birds, both having contrasting traits.
In the video he uses the example of two different colored flowers (purple and white, designated as PP and pp), but I want to think of this as the crossing of two birds, one with Pea Comb (PP) and the other with Single Comb (pp).
A Punnett’s Square will show the results a pure fowl, or fowl that are not pure for a specific trait. This works with any traits that are dominant or recessive, sex-linked traits, and traits that are incomplete dominant or co-dominant.
If you have any questions, be sure to ask me.
Just go to:
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I think im underestimating this now. This is why you said it would be easier to go to the green legs because you know they are pure for it. If i select white legs 1 out of 3 will be pure so it will take longer because ill have to use trial and error to breed the right ones so that the green legs disappear.
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This would be right if both parents were expressing the Pea Comb trait, but were not pure for that trait. Therefore they would be Heterozygous for the Pea Comb trait. This breeding, as you can see from your equations, would give you 3 pea combs, and 1 straight comb. 25% would be pure for the pea comb trait and 25% would be pure for the straight comb trait. And 50% would be pea combed, but not pure for the pea comb trait.
Good Job!
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@I need to watch the videos a few more times to comprehend it fully but can punnett squares explain why pure grey cocks produce all grey offspring when crossed to red hens but not the opposite way crossing red cock on grey hens?
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The reason is, Grey is dominant to Red. Grey bred to red will produce all grey offspring, but these offspring will now carry the recessive red gene, and are not pure for grey.
Check out these programs, I believe they will answer your questions:
COURSE #2 – The Law of Chromosome Segregation (CLICK HERE)
COURSE #6 – Principles of Sex-Linked Inheritance (CLICK HERE)
COURSE #7 – Principles of Dominance (CLICK HERE)
If, after reading these programs, you have any questions, or need more clarification, let me know.
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The diagram you shared here shows exactly what that ratio would be. If you use a Punnett’s square, do it the same, but use supercsrips, Such as ZSZS crossed to ZrW. The best time to use a Punnett’s square to determine Sex-linkage is when the parents are not pure for the traits they are expressing, not so much for pure traits. But this diagram show you the answer you are seeking. In the F1 generation the stags will be silver and the pullets will be red.
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@Is the F2 red cock pure for the hatch traits at this point or is it just sex linked genes?
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@I know the stags would be grey and pulkets red but wouldnt they have a chance for red pullets as well because of the cock carrying sex linked grey genes.
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I’m not sure what your question is here.
Breeding a red cock to grey hen, the diagram is 100 percent accurate.
If the Cock is pure for Grey and the hen is red, both the stags and pullets will be grey.
If the cock is heterozygous grey (not pure) then he can pass the red plumage trait to his sons and daughters. But it’s the hen who determines which traits on the sex-chromome is passed to her sons. She passes no traits from the sex-chromosomes to her daughter.
I hope this helps.
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