Exam 2

Question 1

T/F

The biological phenomenon called hybrid vigor is the result of non-additive genetic merit

Answer 1

True

Question 2

T/F

When heritability is high, phenotype is a good indicator of underlying breeding value (genotype)

Answer 2

True

Question 3

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

Answer 3

True

Question 4

T/F

Traits that are low heritability are influenced more by environment

Answer 4

True

Question 5

T/F

Simply inherited traits are influenced by one gene pair (or few) and typically qualitative

Answer 5

True

Question 6

T/F

Mating decisions are made to increase the proportion of favorable gene combinations in future generations

Answer 6

True

Question 7

T/F

A crossbred is a hybrid. But a hybrid is not always a crossbred

Answer 7

True

Question 8

T/F
A race of animals within a species, usually with a common origin and similar identifying characteristics is called a breed

Answer 8

True

Question 9

T/F

We need purebreds to crossbreed and inbreds to outcross

Answer 9

True

Question 10

T/F

“Better set of genes” = better breeding values

Answer 10

True

Question 11

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

Answer 11

True

Question 12

T/F

In the typical pyramid structure of the meat animal industries, germ plasm flows up the pyramid

Answer 12

False

Question 13

T/F
With regard to proper breeding objectives, more is typically better. Seldom (if ever) is an intermediate optimum the correct breeding objective

Answer 13

False

Question 14

T/F
The kind of animal that works best in one environment may differ from the optimal animal in a different production scenario

Answer 14

True

Question 15

T/F
With regard to the typical pyramid structure information used to determine breeding objectives should flow up the pyramid

Answer 15

True

Question 16

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

Answer 16

True

Question 17

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)

Answer 17

True

Question 18

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

Answer 18

True

Question 19

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

Answer 19

True

Question 20

T/F

Additive genetic merit results in heritability, non-additive genetic merit results in heterosis

Answer 20

True

Question 21

T/F
Relative to mating systems and industry structure, seed stock producers should crossbreed and commercial producers should inbreed

Answer 21

False

Question 22

T/F

Inbreeding= homozygosity = prepotency

Answer 22

True

Question 23

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

Answer 23

True

Question 24

The ability of an indv to produce progeny whose performance is especially like its own and is especially uniform is called

Answer 24

Prepotency

Question 25

Matings within a breed across family lines (crossing unrelated families)

Answer 25

Outcrossing

Question 26

When “Analyzing the System” what are we looking at?

Answer 26

Animals genotypes
Production environment
Fixed resources and management
Production inputs and marketing outputs

Question 27

The relationship between genotypes and phenotypes

Answer 27

Heritability

Question 28

Polygenic traits are

Answer 28

Traits influenced by many genes
Typically more economically important
More challenging to select for than simply inherited traits

Question 29

The process of deciding which animals will become parents?

Answer 29

Replacement selection

Question 30

Selection can be based on

Answer 30

Using info on relatives (pedigree or progeny data)
Genetic prediction
Performance testing

Question 31

The general goal for a breeding program or the idea of what constitutes the best animal?

Answer 31

Breeding objective

Question 32

An observer category or measured level of performance for a trait in an individual

Answer 32

Phenotype

Question 33

Genotype can be split into two components. They are?

Answer 33

Additive and non- additive

Question 34

Which of the following describes selection to improve polygenic traits

Answer 34

Challenging
Long term
Cumulative

Question 35

What factors distort breeding objectives

Answer 35

Competition among purebred breeders
Competitive marketing
End users who rely on the opinions of elite breeders or multipliers

Question 36

Measurement of strength between true genetic value and the predicted genetic value

Answer 36

Accuracy

Question 37

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

Answer 37

Contemporary group

Question 38

Category of traits

Reproduction

Answer 38

Heritability- low

Heterosis- high

Question 39

Category of traits

Growth

Answer 39

Heritability- moderate

Heterosis- moderate

Question 40

Category of traits

Carcass

Answer 40

Heritability- high

Heterosis - low