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VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Biology => Topic started by: sam777 on November 20, 2021, 09:45:23 pm

Title: Determining Genotypes of Gametes With Respect to Linked Genes
Post by: sam777 on November 20, 2021, 09:45:23 pm
If a question stated that a particular individual had the genotype HhGg, where both genes are linked, how do I know what the possible genotypes of the gametes are? Like would they be HG, Hg, Gh, hg? Or is this not correct because they are linked. Does more information about which particular alleles are on which one of their two homologous chromosomes need to be provided? For example, "the dominant alleles are on the same chromosome" and hence I know that the gametes that can be produced are HG and hg.

Thanks!
Title: Re: Determining Genotypes of Gametes With Respect to Linked Genes
Post by: Billuminati on November 21, 2021, 12:17:05 am
If a question stated that a particular individual had the genotype HhGg, where both genes are linked, how do I know what the possible genotypes of the gametes are? Like would they be HG, Hg, Gh, hg? Or is this not correct because they are linked. Does more information about which particular alleles are on which one of their two homologous chromosomes need to be provided? For example, "the dominant alleles are on the same chromosome" and hence I know that the gametes that can be produced are HG and hg.

Thanks!

All 4 gamete allele combinations are theoretically possible, but this depends on the map distance between the gene loci measured by recombination frequency. And yes, you need to know if the alleles are in coupling (dominant on same chromosome) or repulsion (dominant on different chromosomes) phases before you can say which alleles will be the most frequent ones (recombinant chromosomes are less frequent than parental ones).
Title: Re: Determining Genotypes of Gametes With Respect to Linked Genes
Post by: sam777 on November 21, 2021, 12:16:00 pm
Thank you that makes so much more sense now!