A) In the Dunker population, the frequency of IB allele is 0.3 and the frequency of i allele is 0.4. In the general population, the frequency of IB allele is 0.1 and t<span>he frequency of i allele is 0.5.
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If:
- <span>the frequency of IA allele
</span>
- <span>the frequency of IB allele
</span>
- t<span>he frequency of i allele
Then:
</span>
+ <span>
- the frequency of individuals with A blood type
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+ <span>
- the frequency of individuals with B blood type
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<span>- the frequency of individuals with O blood type
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Let's first take a look on the Dunker population:
<span>Since there is only one possible genotype for O individuals - ii - the frequency of the allele i is square root of the frequency of O individuals:
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⇒
⇒
Now, we have the frequencies of two alleles (
and
). To calculate the frequency of
<span> allele, we will use the formula:
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⇒
⇒
⇒
Now, in the general population:
<span>Similarly to the work for the Dunker population:
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⇒
⇒
⇒
⇒
<span>⇒
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b) A founder effect is a result of geographical separation of a few individuals from the original population. Those founding individuals will form a new population. The Dunker population was not only geographically separated, but also genetically. The group interbreeding was present resulting in increasing those allele frequencies that were the most common in the founding population. In this case, the most individuals from the founding population had B blood type.