# Shared Flashcard Set

## Details

Poultry Breeding Exam 3
Info for Poultry Breeding Exam 3
107
Agriculture
01/05/2018

Term
 Mendelian Traits
Definition
 Traits or Characters that are affected by one or few genes, and follow a discontinuous variation.
Term
 Mendelian traits aka...
Definition
 -discontinuous traits-quantitative traits
Term
 distribution of genotypes is affected by...
Definition
 the number of genes involved
Term
 what happens as the number of genes affecting a trait increases?
Definition
 the transition between each genotypic class becomes less distinct, such that it resembles a bell curve, known as normal distriibution
Term
 Quantitative Traits
Definition
 Traits that are affected by many genes, and exhibit continuous variation
Term
 some examples of quantitative traits
Definition
 -growth-egg weight-breast meat yield
Term
 Quantitative traits are...
Definition
 polygenic
Term
 polygenic traits
Definition
 traits affected by many genes
Term
 other than each other, what do alleles interact with to produce traits?
Definition
 the environment
Term
 The analysis of a quantitative trait starts by...
Definition
 describing the phenotype of a given trait in a population
Term
 the distribution most quantitative traits follow
Definition
 normal distribution
Term
 the statistical parameters that govern normal distribution
Definition
 -mean-standard deviation
Term
 standard normal distribution
Definition
 A normal distribution with a mean of zero and a variance of 1
Term
 amount of population within 1 standard deviation of the mean in a standard normal distribution (μ – 1σ and μ + 1σ)
Definition
 68%
Term
 amount of population within 2 standard deviation of the mean in a standard normal distribution (μ – 2σ and μ + 2σ)
Definition
 95%
Term
 amount of population within 3 standard deviation of the mean in a standard normal distribution (μ – 3σ and μ + 3σ)
Definition
 99.7%
Term
 how to calculate proportions of a normal distribution
Definition
 Z = (Xi - μ) / σ then find probability of it on the Z score table
Term
 symbols for mean, variance, and standard deviation for population and sample
Definition
 [image]
Term
 μ
Definition
 population mean
Term
 x
Definition
 sample mean
Term
 σ2
Definition
 population variance
Term
 s2
Definition
 sample variance
Term
 σ
Definition
 population standard deviation
Term
 s
Definition
 sample standard deviation
Term
 mean
Definition
 An arithmetic average
Term
 how to calculate mean
Definition
 Mean = x̄ = (ΣX) / n x̄ = mean phenotypic value of the sample Xi = the ith phenotypic value Σ = the summation sign
Term
 variation
Definition
 in the breeding context, this refers to differences among individuals in a population
Term
 Variation is the source of...
Definition
 genetic change
Term
 the raw material for geneticists
Definition
 variation
Term
 The most commonly used measures for variation
Definition
 -variance-standard deviation
Term
 Variation is measured by...
Definition
 variance or standard deviation
Term
 how to calculate variance
Definition
 σ2 = Σ(Xi - μ)2 / N N = number of individuals in that population
Term
 the best estimate of population variance
Definition
 sample variance, s2
Term
 how to calculate sample variance
Definition
 S2 = Σ(Xi - x̄)2 / (n - 1) or S2 = (ΣXi2 - ((ΣXi)2 / n)) / (n - 1)
Term
 how to calculate standard deviation
Definition
 square root of variance
Term
 positive covariation
Definition
 Y increases as X increases
Term
 negative covariation
Definition
 Y decreases as X increases
Term
 no covariation
Definition
 Y stays the same as X increases or decreases
Term
 3 basic concepts of covariation
Definition
 1.The direction or sign of the relationship, i.e. whether the relationship is positive, negative or non-existence.2.The strength of the relationship.3.The amount of change in one variable that can be expected for a given amount of change in another variable.
Term
 Measures of Covariation
Definition
 1. Covariance2. Correlation3. Regression
Term
 covariance
Definition
 the average product of deviation from the means of two variables
Term
 how to calculate covariance
Definition
 Cov(X,Y) = (Σ(XiYi - n *X̄*Ȳ)) / (n-1)
Term
 Linear correlation
Definition
 a measure of the degree of the relationship between two variables; indicates relationship and strength of it
Term
 how to calculate linear corelation
Definition
 rxy = (Cov(x,y)) / (sx * sy) rxy = ryx
Term
 The simplest functional relationship of one variable to another
Definition
 the simple linear regression
Term
 Regression measures
Definition
 the quantitative change in one variable that can be expected for a unit change in another variable
Term
 the variables involved in linear correlation
Definition
 -dependent variable-independent variable
Term
 relationship between dependent and independent variable
Definition
 the magnitude of the dependent variable is determined by the magnitude of the independent variable
Term
 the relationship between dependent and independent variables if they're linearly related
Definition
 Y = a + byxX this is Y on X, i.e. byx ≠ bxy Y = the dependent variable X = the independent variable b = regression coefficient a = point of intersection (the value of Y when X =0)
Term
 linear regression on a graph
Definition
 [image]
Term
 how to calculate regression variable
Definition
 byx = (Cov(X,Y)) / (Var(X)) bxy = (Cov(X,Y)) / (Var(Y)) byx ≠ bxy
Term
 The most important question about quantitative traits
Definition
 whether or not genes influence the observed variation in the trait
Term
 phenotypic value
Definition
 comprises of the individual’s genetic value and influences from the environment
Term
 environmental factors
Definition
 all non-genetic influences (diet, housing, disease, management)
Term
 some types of environmental factors
Definition
 -diet-housing-disease-management
Term
 how to calculate phenotype value (P)equation for phenotype (P), genotype (G), and environment (E)
Definition
 Phenotype (P) = Genotype (G) + Environment (E)phenotype (P) = Allele value (A) + Dominance (D) + Epistasis (I) + environment (E)
Term
 the basis for genetic improvement
Definition
 differences in genetic values
Term
 why the genetic worth of an individual cannot be judged from the phenotypic value
Definition
 because phenotypic and genotypic ranking could be different
Term
 variation is expressed as...
Definition
 Variancephenotype (P) = genotype (G) + environment (E)
Term
 how to calculate genotypic value
Definition
 Genotype (G) = Allele value (A) + Dominance (D) + Epistasis (I)
Term
 P
Definition
 phenotype
Term
 G
Definition
 genotype
Term
 E
Definition
 environment
Term
 A
Definition
 allele value
Term
 D
Definition
 dominance
Term
 I
Definition
 epistasis
Term
 variance components and their symbols
Definition
 [image]
Term
 Phenotypic variance, VP
Definition
 The total variance is the variation in the performance for a trait between individuals in a population.
Term
 Genotypic variance, VG
Definition
 The variance in the genotypic values for a trait. The genotypic value is the combined effect of...(1) all the alleles at all loci(2) intra-loci interactions(3) inter loci interactions that affect a trait.
Term
Definition
 The variation among alleles transmitted from parents to offspring that affect a trait. The sum of the effect of alleles transmitted from a parent to its offspring for a trait is the Breeding Value (BV) of the parent for that particular trait.
Term
 Breeding Value (BV)
Definition
 The sum of the effect of alleles transmitted from a parent to its offspring for a trait
Term
 Dominance Genetic Variance, VD
Definition
 Genetic variation that occurs as a result of interaction among alleles at a locus. This effect is not accounted for by the effect of two alleles taken singly. For example, assuming the value of A1 is 2, and value of A2 is 3, however the value of the two alleles combined, A1A2 is 7. The dominance deviation in this case is 7 - (2+3) = 2. The combined effect of the two alleles is not additive. The dominance genetic variance measures the non-additive effect between alleles at a locus.
Term
 Epistasis Genetic Variance, VI
Definition
 Genetic variation that occurs as a result of interaction among alleles at different loci. This is also the non-additive effect between genes at different loci.
Term
Definition
 dominance and epistasis genetic variations. non-additive = VD + VI
Term
 Environmental Variation, VE
Definition
 Variation in a trait among animals in a population caused by non-genetic factors, e.g...-housing-feed-temperature-disease-activity-etc.
Term
 The source of variation in a phenotypic value of a trait can be due to...
Definition
 1: genotypic variation2: environmental variation
Term
 some types of genotypic variation
Definition
Term
Definition
 -dominance-epistasis
Term
Definition
 the extent to which an individual’s phenotype is due to its genotype
Term
 how to calculate heritability in the broad sense (H2)
Definition
 H2 = VG / VP or H2 = (VA + VD + VI) / (VA + VD + VI + VE)
Term
 H2
Definition
Term
 heritability in the broad sense reflects the importance of heredity due to...
Definition
 (1) transmission of alleles from parents(2) dominance deviations created at all loci during the formation of zygotes(3) Epistasis deviations created across all loci in the formation of zygotes, in determining phenotypic values
Term
 when Dominance and Epistasis deviations are reconstituted
Definition
 any time a zygote (an individual) is formed and therefore create noise in determining the direct influence of allele values in determining phenotypic values
Term
 heritability in the narrow sense (h2), or just heritability
Definition
 the extent to which phenotype is determined by alleles transmitted from parents to offspring
Term
 how to calculate heritability in the broad sense (h2)
Definition
 h2 = VA / VP or h2 = VA / (VA + VD + VI + VE)
Term
 h2
Definition
 heritability in the narrow sense
Term
 why heritability is important in breeding programs
Definition
 because it determines the degree of resemblance between relatives
Term
 how to calculate Genotypic variance, VG
Definition
 VG = VA + VD + VI
Term
 how to calculate Phenotypic variance, VP
Definition
 VP = VA + VD + VI + VE
Term
 An alternative meaning of heritability
Definition
 the regression of allelic value on phenotypic value
Term
 how to calculate linear regression (bOP) on 1 parent
Definition
 bOP = 1/2 * (h2)
Term
 how to calculate heritability (h2) on 1 parent
Definition
 h2 = 2 bOP h2 = bAP = ((Cov(A,P)) / VP)
Term
 how to calculate Additive Genetic variance (VA) on 1 parent
Definition
 VA = 2 * (Cov, OP)
Term
 how to calculate covariance (Cov (O,P)) on 1 parent
Definition
 Cov (O,P) = 1/2 * VA
Term
 relationship between heritability (h2), linear regression (bOP), and covariance (Cov (O,P))
Definition
 h2 = 2 bOP = ((Cov(O,P)) / VP) = ((1/2 * VA) / VP) VA = 2 (Cov, OP)
Term
 Breeding value (BV)
Definition
 the genetic merit of an animal for a given trait. BV is expressed as a deviation from the mean genetic merit of the trait within a defined population
Term
 The genotype of an individual consists of...
Definition
 (1) allelic values(2) dominance values(3) epistastic values
Term
 how to calculate an animal's transmitting ability (TA)
Definition
 TA = 1/2 * EBVEBV = expected breeding value
Term
 how to calculate breeding value (BV)
Definition
 BV = h2p BV = 2 * (P - [P-bar])
Term
 how to calculate expected breeding value (EBV)
Definition
 EBV = h2 * (P - [P-bar]) EBV = ((nh2) / (1 + (n - 1)re)) * (P - [P-bar]) EBV = ((ngh2) / (1 + (n - 1)t)) * (P - [P-bar]) g = genetic relationship (1/2 for full siblings and 1/4 for half siblings)
Term
 how to calculate accuracy (ACC) of EBV
Definition
 Acc = √(h2 * g) Acc = √((((nh2) / (1 + (n - 1)re))) * g) Acc = √((((ngh2) / (1 + (n - 1)t))) * g) g = genetic relationship (1/2 for full siblings and 1/4 for half siblings)
Term
 repeatability (re)
Definition
 a measure of the reliability or strength of the relationship between repeated measurements on an individual
Term
 how to calculate bAP
Definition
 bAP = ((Cov(A,P)) / VP) bAP = (nh2) / (1 + (n - 1)re)
Term
 genetic relationship between full siblings (FS)
Definition
 g = 1/2
Term
 genetic relationship between half siblings (HS)
Definition
 g = 1/4
Term
 similarity among full siblings (t)
Definition
 tFS = (1/2 * h2) + c2FS c2 = environmental correlation among siblings
Term
 similarity among half siblings (t)
Definition
 tHS = (1/4 * h2) + c2HS c2 = environmental correlation among siblings
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