University:
The University Of Western Ontario
Course:
Biology 2290F | Scientific Method in Biology
Academic year:

2022
Views:

124

Pages:

3
Author:

Kyuwon J.

● Qualitative traits ○ Only exists in given set of numbers of phenotypes ○ One loci controls phenotypes ● Quantitative trait ○ Could be seen as continuous spectrum, range and variation ○ Controlled in multiple loci ○ Wiet, heit, skin tones ● Allele frequency ○ Frequency of allele in population ○ p= frequency of alleles 1 ○ q= frequency of allele 2 ○ p+q=1 ● Genotype frequency ○ Frequency of individual population with certain genotypes ○ p2= expected genotype frequency of allele 1 homozygotes ○ q2 = expected genotypes frequency of allele 2 homozygous ○ 2pq= expected genotype frequency of heterozygotes with all allele HWE is considered genetic equilibrium, if our predicted genotype frequency matches the allele frequency, then we have HWE Calculating Genotypic frequencies ● 120 red flowers ● 10 pink flowers ● 70 white flowers = total 200 indiv flowers Genotype frequency= amount of genotype within the total population ○ Homozygous dominant = 120/200=0.6 ○ Heterozygous 10/200 = 0.05 ○ Homozygous Recessive 70/200 = 0.35 Convert the geneoty frequency to allele ○ ex) ■ Homozygous dominant = 0.2 = 20 ■ Heterozygous=0.3 = 30 ■ Homozygous recessive = 0.5 = 50 ○ Each genotype is caused by TWO alleles Each are caused by 2 alleles, so we multiple by the number of homozygous individuals by 2 two for the homozygous pairs Divide the sum of specific alleles by total number of allele ( number of alleles = number of individual by 2 Important formulas Term Allele Frequency Definition Proportion of an allele in a population Formula (p+q=1) (p) Frequency of dominant allele (A) ( p = \frac{2 \times (AA) + (Aa)}{2N} ) (q) Frequency of recessive allele (a) ( q = \frac{2 \times (aa) + (Aa)}{2N} ) Genotype Frequency Proportion of genotypes in a population ( p2 + 2pq + q2 = 1 ) ( p^2 ) Frequency of AA (homozygous dominant) Calculated from allele frequencies ( 2pq ) Frequency of Aa (heterozygous) ( 2 \times p \times q ) ( q^2 ) Frequency of aa (homozygous recessive) ( q \times q )