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Genetic Problem. Please help out.

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Genetic Problem. Please help out.

Postby BLoCKHeaD » Wed Mar 16, 2005 4:22 am

I have a question and would greatly appreciate if I could get a little help on it.

Consider what would happen during meiosis in a gamete whose diploid number of chromosomes is 4 (2n=4, ie., two sets of homologous chromosomes). Assume that on each set of homologous chromosomes there is a heterozygous pair of alleles for a given trait. What are the genotypic and phenotypic ratios that could result? Use a Punnett Square to Describe the Results.

I know how to make a punnett square with information of alleles but I don't really understand the question? does anybody else? Thanks :lol:
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Postby Nick » Thu Mar 17, 2005 2:40 am

I would assign a genotype first so for the example lets say Bb Bb

First write down your parental genotype Bb X Bb

The write possible gametes B b X B b

Then write possible childrens genotype BB Bb bB bb

Then write possible phenotype 3: Dominant Trait 1: Reccesive
So genotype ratio will be 1:2:1 BB:Bb:bb
phenotype ratio will be 3:1 dominent gene:reccesive gene

Hope this helps
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Postby lohita » Sat Mar 26, 2005 4:07 am

genotypic - hetrozygous , because of the presence of dominant allele
phenotypic - deploid
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Postby MrMistery » Sat Mar 26, 2005 11:13 am

This problem is rulled by Mendel's laws. Might want to take a look at them. Maybe you will understand it beter after that
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Postby Nick » Tue Mar 29, 2005 12:26 pm

Yeh sorry mine is wrong as i read the qst as hetrozygous not homo sorry mate
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