Population Genetics Worksheet (Type in the blanks and submit this worksheet thro
ID: 51432 • Letter: P
Question
Population Genetics Worksheet
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Student Name:
What objects did you use?
Dominant Color (A) Recessive Color (a)
Starting p Starting q
Demonstration #1 – Proper Hardy-Weinburg Conditions
Generation 1
Offspring – AA Aa aa
Total “A alleles” Total “a alleles”
New p New q
New number of dominant objects New number of recessive objects
Generation 2
Offspring – AA Aa aa
Total “A alleles” Total “a alleles”
New p New q
New number of dominant objects New number of recessive objects
Explanation / Answer
Allele frequencies in populations are inferred using Hardy and Weinberg equilibrium. Hardy and Weinberg equilibrium states that in a population, all dominant and recessive alleles comprise all alleles for that gene.
This was mathematically represented as p+ q = 1.0
Where,
p = frequency of dominant alleles
q = frequency of recessive alleles.
Example:
Consider In a population all are heterozygous for a trait, and their genotype is Bb. "B" is the dominant allele that gives blue coloured eyes, and "b" is recessive allele that gives brown coloured eyes. So, initially the values of p and q are equal to 0.5. (initial p = initial q = 0.5).
Generation 1:
The genotypes of the offspring (First generation) will be, 25% BB, 50% Bb, and 25% bb. Consider the number of individuals are 100.
Calculating the number of A alleles: In the population, 25 members have BB genotype, means they have 50 alleles, 50 of Bb population contains 50 B alleles. Thus, the number of A allels is 100.
The frequency of A allele is equal to the total number of alleles = 100/ 200 = 0.5
Similarly, the total number of "a" alleles is 00 and the "a" allele frequency = 50+50/200 = 0.5
Thus, the new p = new q = 0.5 (The genotypic frequencies change with generations, but the allele frequencies remain constant).
Generation 2:
As the population has reached Hardy- Weinberg's equilibrium, the genotypic frequencies do not change, they remain constant as generation 1.
Thus, the genotypes of the offspring (second generation) will be, 25% BB, 50% Bb, and 25% bb.