selection

Question 1

what are 4 things that affect rate of genetic change

Answer 1

h^2
.selection differential
. population size
.generation interval

Question 2

what is selection differential

Answer 2

mean value of selected individual – mean
value of population from which they were
selected

Question 3

what are 4 sources of information based on selection?

Answer 3

1. Individual performance
2. Pedigree – ancestors
3. Collateral relatives
    Half, full sibs
4. Progeny

Question 4

estimated breeding value formula

Answer 4

h2 (x – x)/
2

Question 5

x in EBV stands for what

Answer 5

individual performance

Question 6

x bar stands for what in EBV

Answer 6

Mean contemporary group

Question 7

selection differential

Answer 7

x-xbar

Question 8

higher heritability =

Answer 8

greater accuracy

Question 9

what is a pedigree

Answer 9

information based on ancestor performance

Question 10

advantages of pedigree

Answer 10

Cheap
 Valuable for sex-limited traits
 Valuable for traits expressed later in life
 Low h2 traits
 Attention to records of ancestors
increases accuracy of selection

Question 11

disadvantage of pedigree

Answer 11

Lack of accurate records/environmental
influences of ancestors performance
records
 Provides no comparative basis for
selection among individuals that are all
descendants of same ancestor

Question 12

what is full sibs

Answer 12

same parent

Question 13

half sibs

Answer 13

one parent in common

Question 14

what is progeny testing ?

Answer 14

the evaluation of the genetic makeup of an individual by phenotype of its progeny. genetic worth of an animal

Question 15

what is the major objective of progeny testing for qualitative traits

Answer 15

Help determine likelihood that an animal is
carrier of detrimental recessive

Question 16

what are factors of affecting accuracy of progeny test

Answer 16

Dams must be random
 Offspring tested in same environment
 Compare parents of similar age,
environment
 Increased number of progeny =
increased accuracy