Help - drawing genetic diagrams Watch

BethanyVJ
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I have to draw genetic diagrams to show the possible genotypes of offspring resulting in a cross between
(i) a red bull and a white cow
(ii) a red bull and a roan cow
(iii) a roan bull and a roan cow
For each of the crosses state the ratio of the phenotypes you would expect from the crosses.

Any help with this would be gratefully received! Thanks
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Pink_Sparkles
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(Original post by BethanyVJ)
I have to draw genetic diagrams to show the possible genotypes of offspring resulting in a cross between
(i) a red bull and a white cow
(ii) a red bull and a roan cow
(iii) a roan bull and a roan cow
For each of the crosses state the ratio of the phenotypes you would expect from the crosses.

Any help with this would be gratefully received! Thanks
U didnt post their species , Imean like which one hetrozygous or homozygous etc
If u can post the whole question ?
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BethanyVJ
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(Original post by shahida sulaiman)
U didnt post their species , Imean like which one hetrozygous or homozygous etc
If u can post the whole question ?
Hi, this is what it says before the question: Coat colour in shorthorn cattle is controlled by a codominant gene. 'Red' cattle crossed with 'white' cattle produce offspring which all have a plan brown coat, called roan.

Thank you for helping!
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OxFossil
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Start by giving the gene for coat colour a particular letter - for example, C for red colour and C' for white. (because the genes are co-dominant, I am avoiding using a small letter because the convention is that small letters denote recessive genes/alleles)

Now work out the genotypes of the different coat colours.

Then draw box tables for each of the crosses in i), ii) and iii). This will be a 2x2 table in each case.

The genotypes of the offspring will be whatever appears in the box. From this, you can work out the ratio of genotypes, and therefore the ratio of phenotypes, of the offspring.
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BethanyVJ
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(Original post by OxFossil)
Start by giving the gene for coat colour a particular letter - for example, C for red colour and C' for white. (because the genes are co-dominant, I am avoiding using a small letter because the convention is that small letters denote recessive genes/alleles)

Now work out the genotypes of the different coat colours.

Then draw box tables for each of the crosses in i), ii) and iii). This will be a 2x2 table in each case.

The genotypes of the offspring will be whatever appears in the box. From this, you can work out the ratio of genotypes, and therefore the ratio of phenotypes, of the offspring.
Thank you! I have done it now i think!
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