Exam 3

Question 1

What are causes of correlated response?

Answer 1

Linkage

Pleiotropy

Question 2

What is linkage?

Answer 2

Major genes affecting two traits that are closely linked

Question 3

Why is linkage considered temporary?

Answer 3

Because of recombination

Question 4

What is pleiotropy?

Answer 4

Gene influences more than one trait

Question 5

What is pleiotropy a major cause of?

Answer 5

Halothane gene–HYPP

Question 6

What do correlated response to selection result from?

Answer 6

Genetic correlations between traits

Question 7

What are the 3 types of correlation?

Answer 7

Genetic
Phenotypic
Environmental

Question 8

What does genetic correlation measure?

Answer 8

The relative importance of pleiotropic effects on 2 traits

Question 9

What is the symbol for genetic correlation?

Answer 9

r_BVx, BVy

Question 10

What does phenotypic correlation measure?

Answer 10

The strength of the relationship between performance of one trait and performance of another

Question 11

What is the symbol for phenotypic correlation?

Answer 11

r_Pbw, Pyw

Question 12

What is environmental correlation a measure of?

Answer 12

The strength of the relationship between environmental effects of one trait and environmental effects of another

Question 13

What is the symbol for environmental correlation?

Answer 13

r_Ebw, Eyw

Question 14

What are higher weaning and yearling weights generally associated with?

Answer 14

Higher birth weights

Question 15

What are higher growth rates generally associated with?

Answer 15

Larger scrotal circumferences and ribeye areas

Question 16

What are higher growth EPDs generally associated with?

Answer 16

Lower maternal milk EPDs

Question 17

What are higher maternal milk EPDs generally associated with?

Answer 17

Higher marbling in progeny

Question 18

What are factors affecting correlated response?

Answer 18

Correlation between traits
h^2
i
σp (phenotypic variation)
L

Question 19

What is the formula for rate of genetic change?

Answer 19

(r_BVx,BVy x hx x hy x i_x x σpy) / L

Question 20

READ CHAPTER 13

Answer 20

READ CHAPTER 13

Question 21

What are the 2 methods of multiple trait selection?

Answer 21

Tandem selection

Independent culling levels

Question 22

What is tandem selection?

Answer 22

Selection for one trait then another

Question 23

What is the selection target in tandem selection?

Answer 23

Optimal level needed to be reached

Question 24

What do you need to be carful of in tandem selection?

Answer 24

Genetic correlations

Question 25

What is the independent culling levels method of selection?

Answer 25

Minimum standards for traits undergoing multiple trait selections Allows you to select simultaneously for more than one trait

Question 26

What does the economic selection index predict?

Answer 26

The aggregate breeding value from multiple trait selections

Question 27

What is the equation for aggregate breeding value?

Answer 27

H = v1BV1 + v2BV2+.... vmBVm

Question 28

What is the phenotypic selection index?

Answer 28

A form of economic selection index used with phenotypic selection

Question 29

What is the equation for phenotypic selection index?

Answer 29

I = b1x1 + b2x2+.....

Question 30

READ CHAPTER 14

Answer 30

READ CHAPTER 14

Question 31

What is backcrossing?

Answer 31

The mating of a hybrid to a purebred of a parent breed or line

Question 32

What is grading up?

Answer 32

Mating system used to create purebred population or convert one breed to another

Question 33

READ CHAPTER 15

Answer 33

READ CHAPTER 15

Question 34

What happens in random mating?

Answer 34

Mates chosen at random All matings are equally likely to occur Gate cutting, assigning numbers

Question 35

Where is random mating popular?

Answer 35

Commercial operations

Question 36

What is random mating best for?

Answer 36

Sire evaluations

Question 37

What is assortative mating?

Answer 37

Planned matings

Question 38

What matings occur in assortative?

Answer 38

Mating of similar or dissimilar individuals

Question 39

Is assortative less or more difficult that random mating? Why?

Answer 39

More difficult | Multiple traits

Question 40

What are the 2 types of assortative breeding?

Answer 40

Positive | Negative

Question 41

What is positive assortative breeding?

Answer 41

``` Best animal to the best animal Creates more variation Increases genetic variation Produces extreme individuals Decreases uniformity ```

Question 42

What is negative assortative breeding?

Answer 42

``` Best animal to the worst animal Decrease variation Produce more intermediates Reduce extreme individuals Increase uniformity ```

Question 43

What does negative assortative correct?

Answer 43

Progeny faults

Question 44

What are 2 different types of negative assortative breeding?

Answer 44

Complementarity matings | Crossbreeding

Question 45

What are complementarily matings?

Answer 45

Matings of individuals with different but complementary breeding values

Question 46

What is the overall performance of offspring like in complementarity matings?

Answer 46

It is superior to the average of parents

Question 47

READ CHAPTER 16

Answer 47

READ CHAPTER 16