Animal Genetics test 2 Flashcards
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The branch of genetics concerned with influences on, measurement of, relationships among, genetic prediction for and rate of change in traits that are quantitative, or continuous, in nature (such as weight or height)
quantitative genetics
discrete traits controlled by a few alleles at one or a few loci and influenced little or none by the environment. traits such as coat color for which phenotypes can be classified into groups or classes.
qualitative traits
traits that have quantitative value, traits influenced by many alleles at several different loci that have a continuous expression and are effected by the environment
quantitative traits
a trait affected by many genes, no single gene having an override influence
polygenic trait
the ability of one allele to express its phenotype at the expense of the alternate allele; an interaction between genes at a single locus such that in heterozygotes one allele has more effect than the other.
Dominance
an interaction among genes at different loci such that expression of genes at one locus depends on alleles present at one or more other loci
epistasis
the effect that external (non genetic) factors have on animal performance
Environmental effect
an environmental effect that influences a single performance record of an individual, but does not permanently affect the individuals performance potential for a repeated trait
Temporary environmental effect
an environmental effect that permanently influences an individuals performance for a repeated trait
Permanent environmental effect
breeding effects that are consistently transmitted from parents transmitted from parents to progeny , the additive genetic worth of an animal relative to some base population, the worth of an individual as a (genetic) parent.
Breeding Value
predication of genetic value derived from the application of genetic theory and statistics to performance records; estimate of unknown breeding value.
Estimated breeding value
an estimate, or prediction, of how much better or poorer an individuals progeny will perform compared to the average of all individuals in the breed.
Expected progeny difference
a trait for which individuals commonly have more than one performance record
Repeated trait
the performance potential of an individual for a repeated trait, (milk production;wool production;racing ability)
Producing ability
any quantity that can take on different numerical values. all elements (except u) of the genetic model for quantitative traits - P, BV, E - are considered
Variable