Exam 2 Flashcards
T/F
The biological phenomenon called hybrid vigor is the result of non-additive genetic merit
True
T/F
When heritability is high, phenotype is a good indicator of underlying breeding value (genotype)
True
T/F
The two basic tools used to improve animal populations are selection and mating. Mating is the process of determining which males are mated to which females
True
T/F
Traits that are low heritability are influenced more by environment
True
T/F
Simply inherited traits are influenced by one gene pair (or few) and typically qualitative
True
T/F
Mating decisions are made to increase the proportion of favorable gene combinations in future generations
True
T/F
A crossbred is a hybrid. But a hybrid is not always a crossbred
True
T/F
A race of animals within a species, usually with a common origin and similar identifying characteristics is called a breed
True
T/F
We need purebreds to crossbreed and inbreds to outcross
True
T/F
“Better set of genes” = better breeding values
True
T/F
Genetic prediction is an are of animal breeding concerned with the measurement of data, statistical procedures and computational techniques for predicting breeding values
True
T/F
In the typical pyramid structure of the meat animal industries, germ plasm flows up the pyramid
False
T/F
With regard to proper breeding objectives, more is typically better. Seldom (if ever) is an intermediate optimum the correct breeding objective
False
T/F
The kind of animal that works best in one environment may differ from the optimal animal in a different production scenario
True
T/F
With regard to the typical pyramid structure information used to determine breeding objectives should flow up the pyramid
True
T/F
The point at which a particular allele becomes the only allele at its locus and the gene frequency of this allele becomes 1, is called fixation
True
T/F
Most breeding industries have a pyramid structure including relatively few elite breeders selling breeding stock to a larger number of multiplier breeders who sell breeding stock to a great number of end users (commercial breeders)
True
T/F
An important responsibility of purebred seed stock breeders is to make genetic improvements in the economically important traits in their respective meat animal industry
True
T/F
The two fundamental questions of animal breeders are
1) what is the best animal
2) how do we breed animals so that their offspring will be better than their parents
True
T/F
Additive genetic merit results in heritability, non-additive genetic merit results in heterosis
True
T/F
Relative to mating systems and industry structure, seed stock producers should crossbreed and commercial producers should inbreed
False
T/F
Inbreeding= homozygosity = prepotency
True
T/F
Genotype x Environment interaction is a dependent relationship between genotypes and environments in which the diff in perf between two or more genotypes changes from env to env
True
The ability of an indv to produce progeny whose performance is especially like its own and is especially uniform is called
Prepotency
Matings within a breed across family lines (crossing unrelated families)
Outcrossing
When “Analyzing the System” what are we looking at?
Animals genotypes
Production environment
Fixed resources and management
Production inputs and marketing outputs
The relationship between genotypes and phenotypes
Heritability
Polygenic traits are
Traits influenced by many genes
Typically more economically important
More challenging to select for than simply inherited traits
The process of deciding which animals will become parents?
Replacement selection
Selection can be based on
Using info on relatives (pedigree or progeny data)
Genetic prediction
Performance testing
The general goal for a breeding program or the idea of what constitutes the best animal?
Breeding objective
An observer category or measured level of performance for a trait in an individual
Phenotype
Genotype can be split into two components. They are?
Additive and non- additive
Which of the following describes selection to improve polygenic traits
Challenging
Long term
Cumulative
What factors distort breeding objectives
Competition among purebred breeders
Competitive marketing
End users who rely on the opinions of elite breeders or multipliers
Measurement of strength between true genetic value and the predicted genetic value
Accuracy
Set of animals of the same sex managed alike close to the same age group and given the same opportunity to perform in the same environment
Contemporary group
Category of traits
Reproduction
Heritability- low
Heterosis- high
Category of traits
Growth
Heritability- moderate
Heterosis- moderate
Category of traits
Carcass
Heritability- high
Heterosis - low
