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    Analysis of Alleles

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    1. If a population consists of 122 individuals, how many alleles are present in the population?
    2. In the same population of 122 individuals, 25% have the recessive phenotype.
    a. How many individuals have the recessive phenotype?
    b. How many alleles are present in individuals with the recessive phenotype?

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    https://brainmass.com/biology/genetics/analysis-alleles-521733

    SOLUTION This solution is FREE courtesy of BrainMass!

    1. If a population consists of 122 individuals, how many alleles are present in the population?

    There are 20,000-25,000 protein coding genes in the human genome. While each gene may have more than two alleles per gene, each person can only carry a maximum of two different alleles at each gene.

    Exactly how many unique alleles are present in a population would depend on the frequency of each allele for each gene.

    However, we can calculate the number of allele positions for the 20,000-25,000 protein coding genes in the human genome. Since each person can have a maximum of two allele positions, the total alleles per person is 40,000-50,000. In a a population of 122, that would mean 4,800,000-6,100,000 possible allele positions. Also, remember that the sex chromosomes do not necessarily have corresponding alleles.

    The Hardy-Weinberg equilibrium can be used to calculate the frequency of alleles in a population of known size as long as we know how many alleles there are for the given gene and some phenotype data.

    Please follow up if this answer is not what you are looking for. The question is worded in such a way that it might reflect something specific your professor said in class.

    2. In the same population of 122 individuals, 25% have the recessive phenotype.

    a. How many individual have the recessive phenotype?
    The number of individuals is 30 (122*0.25 = 30.5, round down because you cannot have half a person).
    b. How many alleles are present in individuals with the recessive phenotype?
    A recessive phenotype is caused by two copies of a recessive allele. That means that there is only one allele (duplicated) at the gene in question.

    Additional references (valid 01/17/2013):
    http://www.ncbi.nlm.nih.gov/pubmed/15496913
    http://www.ndsu.edu/pubweb/~mcclean/plsc431/popgen/popgen2.htm
    http://atlasgeneticsoncology.org/Educ/HardyEng.html
    http://www.emunix.emich.edu/~rwinning/genetics/populat.htm.

    This content was COPIED from BrainMass.com - View the original, and get the already-completed solution here!

    © BrainMass Inc. brainmass.com December 24, 2021, 10:57 pm ad1c9bdddf>
    https://brainmass.com/biology/genetics/analysis-alleles-521733

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