ANSC 4395 BREEDING & GENETICS - TEST 3 GRADED A+ 100% VERIFIED.
Simply-Inherited Traits ANS >> traits affected by only a few genes
qualitative or categorical
affected little by environment
Quantitative ANS >> measured with numbers
Polygenic Traits ANS >> Affected by many genes with no gene having an overriding
influence.
- EX: Growth rate, milk production, ribeye area
Typically, quantitative or continuous in expression.
- Phenotypes are usually described by numbers
Greatly influenced by environment
Examples of Simply-Inherited Traits ANS >> Coat colour, horns
Examples of Polygenic Traits ANS >> Weaning weights, milk yield, REA... CAN’T DO
TEST MATINGS FOR THIS TYPE OF TRAIT
Threshold Traits ANS >> Polygenic traits that have categorical phenotypes
, - Pregnancy, dystocia, gait
- Influenced by many genes but have an either/or result
Which traits are more important? ANS >> Polygenic traits, traits that determine
profitability and productivity
EX) Growth rate, fertility, milk production
Niche markets ANS >> markets more sensitive to simply-inherited traits
Simply Inherited ANS >> Genetic Defects
Common characteristics of Polygenic and Simply Inherited ANS >> 1. Both are
subject to the same Mendelian Mechanisms: Law of Segregation and Independent
Assortment
2. Affected by dominance and epistasis
3. Principles of selection and mating apply to both
- Attempt to increase frequency of desirable alleles
(More difficult to do with polygenic traits)
Function of the Number of genes involved ANS >> - The more genes involved, the
more DIFFICULT it is to observe the effects of individual genes, and therefore the
less specific info we have about those genes
- When a few or one gene affects a trait, the effects of those genes are well
understood (Exact genotype may not be known, but a probable genotype may be
identified.)
Simply-Inherited Traits ANS >> traits affected by only a few genes
qualitative or categorical
affected little by environment
Quantitative ANS >> measured with numbers
Polygenic Traits ANS >> Affected by many genes with no gene having an overriding
influence.
- EX: Growth rate, milk production, ribeye area
Typically, quantitative or continuous in expression.
- Phenotypes are usually described by numbers
Greatly influenced by environment
Examples of Simply-Inherited Traits ANS >> Coat colour, horns
Examples of Polygenic Traits ANS >> Weaning weights, milk yield, REA... CAN’T DO
TEST MATINGS FOR THIS TYPE OF TRAIT
Threshold Traits ANS >> Polygenic traits that have categorical phenotypes
, - Pregnancy, dystocia, gait
- Influenced by many genes but have an either/or result
Which traits are more important? ANS >> Polygenic traits, traits that determine
profitability and productivity
EX) Growth rate, fertility, milk production
Niche markets ANS >> markets more sensitive to simply-inherited traits
Simply Inherited ANS >> Genetic Defects
Common characteristics of Polygenic and Simply Inherited ANS >> 1. Both are
subject to the same Mendelian Mechanisms: Law of Segregation and Independent
Assortment
2. Affected by dominance and epistasis
3. Principles of selection and mating apply to both
- Attempt to increase frequency of desirable alleles
(More difficult to do with polygenic traits)
Function of the Number of genes involved ANS >> - The more genes involved, the
more DIFFICULT it is to observe the effects of individual genes, and therefore the
less specific info we have about those genes
- When a few or one gene affects a trait, the effects of those genes are well
understood (Exact genotype may not be known, but a probable genotype may be
identified.)
