exam 2

Question 1

what are statistics used for? (3)

Answer 1

evaluating numbers
describing the population
estimating unknown value

Question 2

what are traits measured for? (2)

Answer 2

continuous variation or didcontinuous variation

Question 3

what are some characteristics of continuous variation?

Answer 3

quantitative traits, many genes, small gradations, economically important, and tightly complex.

Question 4

what are some examples of continuous variation.

Answer 4

weight gain and fertility

Question 5

what is a sample used for?

Answer 5

it analyzes data from a population

Question 6

what is the population perameter?

Answer 6

it describes the populatiom

Question 7

what is a sample statistic?

Answer 7

a numerical descriptive measure of a sample

Question 8

what does the central tendancy mean?

Answer 8

when values cluster at a midpoint and thins out at both extremes evenly.

Question 9

define median, mean, and mode

Answer 9

median- halfway value between two extremes
mean- average
mode- class with the highest frequency

Question 10

what is variance?

Answer 10

a measure of distribution

Question 11

what is the equation for variance?

Answer 11

s^2=(Σ(x-x̄)^2)/(n-1)

Question 12

what is the most useful statistic?

Answer 12

the mean

Question 13

what are the three measurements of dispersion?

Answer 13

variance, standard deviation, and standard error

Question 14

what is the equation for standard deviation?

Answer 14

squared root of s^2

Question 15

what is the equation for standard error?

Answer 15

se= standard deviation/the square root of n

Question 16

what is correlation?

Answer 16

a measure of relationship between two variables

Question 17

what is the correlation equation?

Answer 17

r=(Σxy-(Σx Σy)/n)/the square root of (Σx^2-(Σx)^2/n)(Σy^2-(Σy)^2/n)

Question 18

what are the ranges for correlation and what does it mean?

Answer 18

low- .01-.2
medium- .21-.4
high- >.41

Question 19

what is the phenotypic correlation?

Answer 19

strength of relationship between the performance in one trait and the performance in another.

Question 20

what is performance?

Answer 20

phenotypic value

Question 21

what is genetic correlation?

Answer 21

strength of relationship between breeding value for one trait and breeding value in another

Question 22

what are two reasons correlated response exists

Answer 22

gene linkage and pleotrophy

Question 23

what is environmental correlation?

Answer 23

a measurement of strength of relationships between environmental effects

Question 24

what is the regression coefficent?

Answer 24

b=((ΣXY)-(ΣX)(ΣY))/n/((Σx^2)-(Σx)^2)/n

Question 25

what is regression?

Answer 25

expected change in y to x

Question 26

what are simply inherited traits?

Answer 26

traits that are affected by few genes, such as coat color

Question 27

environmental factors have ______ effect on traits

Answer 27

little

Question 28

what are polygenic traits?

Answer 28

traits affected by many genes, such as milk productions.

Question 29

what do the letters in this equation mean? P= μ+G+E

Answer 29

P- phenotypic value μ- population mean G- genotypic value E- environmental factors

Question 30

what is genotypic value and how do you find it?

Answer 30

the overall effect of all genes carried in an animal; G=breeding value (BV)+ gene combination value (GCV)

Question 31

what is breeding value?

Answer 31

genotypic value that can be transmitted from parent to offspring

Question 32

what is the breeding value equation

Answer 32

the mean of the breeding value of the offspring= the breeding value of the sire+BV of the dom/2

Question 33

y can not equal _, and cant fall outside the ______ of values.

Answer 33

a; range

Question 34

what does EPD mean? which animals is it used for?

Answer 34

expected progeny difference. beef, swine, sheep

Question 35

what does PTA mean? what animals is it used for?

Answer 35

predicted transmission ability. dairy cattle

Question 36

what are mating systems used for?

Answer 36

it chooses which males are to be bred with which female

Question 37

what is the goal of selection?

Answer 37

to increase desired alleles

Question 38

what is inbreeding good for?

Answer 38

making animals more homozygous for superior genes from an ancestor

Question 39

what is outbreeding good for?

Answer 39

increasing heterozygosity and hybrid vigor

Question 40

what are the effects of inbreeding?

Answer 40

``` prepotency expression of deleterious recessive alleles inbreeding depression fixed characteristics concentrates genes increases similar genes ```

Question 41

what is the equation of measuring inbreeding?

Answer 41

Fx= Σ1/2^(n1+n2+1)(1+Fca)

Question 42

what is the equation for genetic relationships?

Answer 42

Rxy= Σ1/2n(1+Fca)/the square root of (1+Fx)(1+Fy)

Question 43

what is outbreeding

Answer 43

the mating between individuals not closely related genetically, but within the same breed

Question 44

where is outbreeding used alot?

Answer 44

the poultry industry

Question 45

what is grading up?

Answer 45

the mating of PUREBLOOD MALES to NONPUREBLOOD females

Question 46

what is cross breeding?

Answer 46

the crossing of different breeds such as a horse and a donkey

Question 47

what does synthetic mean?

Answer 47

combination of different lines of ancestry

Question 48

what is heterosis?

Answer 48

increased heterozygosity

Question 49

what is the net effect?

Answer 49

influences affecting the trait

Question 50

what is the equation for % heterosis?

Answer 50

the mean of the offspring + the mean of the parents divided by the mean of the parents all multiplied by 100

Question 51

what is breed compelation?

Answer 51

combining desired traits in two or more breeds

Question 52

what are the major uses of outbreeding?

Answer 52

commercial cow/calf, swine, poultry, and sheep

Question 53

what is limited crossbreeding used for?

Answer 53

dairy, poultry, and wool sheep

Question 54

what does hybrid vigor increase in dairy cattle

Answer 54

feetility, health, and survivability

Question 55

what is GCA and what is it used for?

Answer 55

general combination ability; they are used for multiple breeds

Question 56

what is SCA and what is it used for?

Answer 56

specific combining ability; used for only 2 breeds

Question 57

what does days open mean?

Answer 57

the window of fertility

Question 58

what are the systems for cross breeding?

Answer 58

``` define objectives breeds herd size implementation cost vs. expexted return nothing is free ```

Question 59

what are the three major cross breeding systems

Answer 59

terminal, rotational, and rotaterminal