ANSC 4395 EXAM 4 – 2025/2026 – QUESTIONS WITH VERIFIED ANSWERS (GRADED A+)
Quantitative traits - (answers)-weights
-heights
-litter size
-number of eggs
-racing speed
controlled by many pairs of genes
Genetic effects - (answers)-Additive effects
-Dominance effects
-Epistatic Effects
If a trait is controlled by many pairs of genes with additive gene action, it will be easier to make
improvement through selection - (answers)•Because every added desirable gene has a direct impact on
the expected phenotype
Epistasis - (answers)Interaction among genes at multiple loci
Subdivision of environmental components - (answers)-Temporary environment effects
-Permanent environmental effects
If there is a normal distribution of phenotypes - (answers)There is a normal distribution of:
-Additive effects
, -Dominance effects
-Epistatic effects
-Permanent environmental effects
-Temporary environmental effects
Heritability - (answers)•The proportion of the phenotypic variation which is due to additive gene effects
-The most important single concept in animal breeding
-In general it tells us how easy it is to make improvements through selection
-varies from herd to herd
-Varies with any herd if management changes
The importance of reproductive traits - (answers)-Compensates for the low heritability
-Should be included in most selection programs
Phenotypic Correlation - (answers)•Association between actual performance for 2 traits
-Has both a genetic and environmental contribution
-WW and ADG =.20
Genetic Correlation - (answers)•Association between genetic merit for two traits
Quantitative traits - (answers)-weights
-heights
-litter size
-number of eggs
-racing speed
controlled by many pairs of genes
Genetic effects - (answers)-Additive effects
-Dominance effects
-Epistatic Effects
If a trait is controlled by many pairs of genes with additive gene action, it will be easier to make
improvement through selection - (answers)•Because every added desirable gene has a direct impact on
the expected phenotype
Epistasis - (answers)Interaction among genes at multiple loci
Subdivision of environmental components - (answers)-Temporary environment effects
-Permanent environmental effects
If there is a normal distribution of phenotypes - (answers)There is a normal distribution of:
-Additive effects
, -Dominance effects
-Epistatic effects
-Permanent environmental effects
-Temporary environmental effects
Heritability - (answers)•The proportion of the phenotypic variation which is due to additive gene effects
-The most important single concept in animal breeding
-In general it tells us how easy it is to make improvements through selection
-varies from herd to herd
-Varies with any herd if management changes
The importance of reproductive traits - (answers)-Compensates for the low heritability
-Should be included in most selection programs
Phenotypic Correlation - (answers)•Association between actual performance for 2 traits
-Has both a genetic and environmental contribution
-WW and ADG =.20
Genetic Correlation - (answers)•Association between genetic merit for two traits
