quantitative genetics

• Quantitative Genetics


  field of genetics that analyzes how genetic and environmental factors influence the inheritance and expression of a quantitative trait
• Quantitative Traits


  are small differences that can be measured such as size, weight, IQ
• Quantitative Traits


  these traits are much more difficult to analyze since they are continuous
• Multiple Genes


  quantitative traits are governed by multiple genes that additively encamps a certain trait
• multiple factors


  genes of the same type
• polygenes


  termed by Mather to mean those genes that are additive which produces observable quantitative changes
• Mean


  central value of a set of sample observation, average
• Median


  middle value of an array
• Mode


  most frequent value
• Class interval


  refers to individual observation classified into group of specific measurements, such as length, weight, or height
• Frequency distribution


  refers to frequencies for each group or class interval co lected together
• Normal distribution


  type of distribution where the central class (mean, median, mode) coincide the highest point of frequency
• Variance


  deviation from the population mean; = (summation of individual observation- population mean)^2 / Population size
• Covariance


  measures similarity of measurements of 2 parameters; Cxy = summation of (Xi-Xm)(Yi-Ym) / sample size- 1
• Coefficient of Variance


  measures comparability of variation of different samples or experiments; (Sample / mean) x 100
• Standard error


  indicates how much the mean population of other samples of the same size drawn from the same population may be expected to vary
• Additive (A)


  phenotypic expression owing to individual effect
• Dominance (D)


  phenotypic expression owing to the interaction of the a lele pair
• Epistasis (E)


  phenotypic expression owing to the gene interaction