ANSC 4395 Final Exam QUESTIONS WITH COMPLETE ANSWERS
Quantitative traits are those that can be __________________. Correct Answer: Measured
Some examples of quantitative traits Correct Answer: Weights
Heights
Litter size
Number of eggs
Racing speed
Quantitative traits are controlled by Correct Answer: Many pairs of genes
Effects of _______ _________ of genes cannot be distinguished. Correct Answer: One pair
The activity at any one pair of genes is ______________ to the types of gene action discussed in
simply-inherited traits. Correct Answer: Identical
The outward appearance of an individual. Correct Answer: Phenotype
The phenotype for quantitative traits is usually a _____________________. Correct Answer:
Measurement
The __________ of the genetic and environmental factors which have an effect. Correct Answer:
Sum
Formula for phenotype Correct Answer: P = G + E
Both genetic and environmental factors can be ___________________ into more explicit
components. Correct Answer: Subdivided
Genetic effects can be divided into Correct Answer: Additive effects
Dominance effects
Epistatic effects
Occur when two or more genes source a single contribution to the final phenotype. Correct
Answer: Additive Effect
Phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the effect
of a different variant of the same gene on the other copy of the chromosome. Correct Answer:
Dominance Effect
The phenomenon where the effects of one gene are modified by one or several other genes at
different loci. Correct Answer: Epistatic Effect
Dominance is ______ always complete. Correct Answer: Not
, __________________ is exactly half way between the homozygotes. Correct Answer:
Heterozygote
When dominance is present, it affects our ability to make what? Correct Answer: Selection
decisions
If a trait is controlled by many pairs of genes with additive gene action, it will be easier to make
improvement through ___________________. Correct Answer: Selection
Interaction among genes at multiple loci. Correct Answer: Epistasis
May have interaction between 2, 3, or more loci. Correct Answer: Epistasis
Gene action at one locus may not be _______________. Correct Answer: Constant
These are sources of environmental variation that have somewhat of a temporary effect. Correct
Answer: Temporary environmental effects
Change the way an animal performs for the rest of its life. Correct Answer: Permanent
environmental effects
_______________ is the square of the standard deviation. Correct Answer: Variance
The best animals may have: Correct Answer: Best additive genotype
Best dominance genotype
Best epistatic genotype
Best permanent environment genotype
Best temporary environment genotype
The proportion of the phenotypic variation which is due to additive gene effects. Correct
Answer: Heritability
The most important single concept in animal breeding. Correct Answer: Heritability
Heritability is symbolized as Correct Answer: h^2
Provides information about differences between individuals and the nature of the variation within
a population. Correct Answer: Heritability
Heritability is not constant, is varies... Correct Answer: From herd to herd
Within a herd if management changes
Makes it much easier to show selection progress for growth and carcass traits than for
reproductive traits. Correct Answer: Heritability
Quantitative traits are those that can be __________________. Correct Answer: Measured
Some examples of quantitative traits Correct Answer: Weights
Heights
Litter size
Number of eggs
Racing speed
Quantitative traits are controlled by Correct Answer: Many pairs of genes
Effects of _______ _________ of genes cannot be distinguished. Correct Answer: One pair
The activity at any one pair of genes is ______________ to the types of gene action discussed in
simply-inherited traits. Correct Answer: Identical
The outward appearance of an individual. Correct Answer: Phenotype
The phenotype for quantitative traits is usually a _____________________. Correct Answer:
Measurement
The __________ of the genetic and environmental factors which have an effect. Correct Answer:
Sum
Formula for phenotype Correct Answer: P = G + E
Both genetic and environmental factors can be ___________________ into more explicit
components. Correct Answer: Subdivided
Genetic effects can be divided into Correct Answer: Additive effects
Dominance effects
Epistatic effects
Occur when two or more genes source a single contribution to the final phenotype. Correct
Answer: Additive Effect
Phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the effect
of a different variant of the same gene on the other copy of the chromosome. Correct Answer:
Dominance Effect
The phenomenon where the effects of one gene are modified by one or several other genes at
different loci. Correct Answer: Epistatic Effect
Dominance is ______ always complete. Correct Answer: Not
, __________________ is exactly half way between the homozygotes. Correct Answer:
Heterozygote
When dominance is present, it affects our ability to make what? Correct Answer: Selection
decisions
If a trait is controlled by many pairs of genes with additive gene action, it will be easier to make
improvement through ___________________. Correct Answer: Selection
Interaction among genes at multiple loci. Correct Answer: Epistasis
May have interaction between 2, 3, or more loci. Correct Answer: Epistasis
Gene action at one locus may not be _______________. Correct Answer: Constant
These are sources of environmental variation that have somewhat of a temporary effect. Correct
Answer: Temporary environmental effects
Change the way an animal performs for the rest of its life. Correct Answer: Permanent
environmental effects
_______________ is the square of the standard deviation. Correct Answer: Variance
The best animals may have: Correct Answer: Best additive genotype
Best dominance genotype
Best epistatic genotype
Best permanent environment genotype
Best temporary environment genotype
The proportion of the phenotypic variation which is due to additive gene effects. Correct
Answer: Heritability
The most important single concept in animal breeding. Correct Answer: Heritability
Heritability is symbolized as Correct Answer: h^2
Provides information about differences between individuals and the nature of the variation within
a population. Correct Answer: Heritability
Heritability is not constant, is varies... Correct Answer: From herd to herd
Within a herd if management changes
Makes it much easier to show selection progress for growth and carcass traits than for
reproductive traits. Correct Answer: Heritability
