Exam 2 Definitions

Question 1

Variation

Answer 1

differences among individuals within a population

Question 2

Covariation

Answer 2

how two traits or values vary together

Question 3

Correlation

Answer 3

the measure of strength (reliability) of the relationship between two variables

Question 4

Regression

Answer 4

the expected (average) change in one variable per 1 unit change in the other

Question 5

Population mean

Answer 5

the mean phenotypic value of all individuals in the population

Question 6

Basic genetic model

Answer 6

a mathematical representation of how performance (P) is affected by both nature (G) and nurture (E)

Question 7

Breeding value

Answer 7

the value of an individual as a (genetic) parent

Question 8

Additive properties

Answer 8

an animal’s breeding value (or progeny difference) for a trait is a function of all the independent effects of the animal’s alleles affecting that trait

Question 9

Gene combination value

Answer 9

the effect of combination (interaction) of genes/alleles

Question 10

Permanent environmental effect

Answer 10

permanently influences an individual’s performance

Question 11

Temporary environmental effect

Answer 11

does not permanently affect an animal’s performance

Question 12

Contemporary group

Answer 12

set of animals with equal opportunity to perform

Question 13

Repeated trait

Answer 13

a trait for which individuals have more than one performance record

Question 14

Producing ability

Answer 14

performance potential of an individual for a repeated trait

Question 15

Heritability

Answer 15

measure of how offspring resemble their parents

Question 16

Repeatability

Answer 16

the change in producing ability expected per unit change in phenotypic value

Question 17

Producing Ability

Answer 17

function of all factors that permanently affect an individual’s ability to perform

Question 18

Accuracy of selection

Answer 18

the strength of the relationship between true breeding values and their predictions

Question 19

Selection intensity

Answer 19

how choosy breeders are in deciding which individuals are selected

Question 20

Generation Interval

Answer 20

the amount of time required to replace one generation with the next

Question 21

Progeny testing

Answer 21

collecting evidence on the genetic value of an animal by gathering data on his/her offspring

Question 22

Marker assisted selection

Answer 22

specific genetic test for causative mutation or a handful of genes with known impact

Question 23

Single nucleotide polymorphisms

Answer 23

tens or hundreds of thousands of SNPs evaluated at one time

Question 24

Accuracy

Answer 24

the correlation between the BV of the individual and the and the source of information used to predict its BV

Question 25

Best linear unbiased prediction (BLUP)

Answer 25

a statistical method for predicting BV that combines information from all available sources (e.g., own, pedigree, progeny)