Ch. 7

Question 1

Quantitative Genetics

Answer 1

The branch of genetics concerned w/ influences on, measurement of, relationships among, genetic prediction for, and rate of change in traits that are or can be treated as quantitative.

Question 2

Phenotypic value (P)

Answer 2

A measure of performance for a trait in an individual- a performance record

Question 3

Population Mean

Answer 3

The avg. phenotypic value of all individuals in a population.

Question 4

Genotypic Value (G)

Answer 4

The effect of an individual’s genes (singly & in combination) on its performance for a trait.

Question 5

Environmental Effect

Answer 5

The effect that external (nongenetic) factors have on animal performance.

Question 6

Value

Answer 6

(in animal breeding) Any measure applied to an individual as opposed to a pop. Exs. are phenotypic value, genotypic value, breeding value, & environmental effect.

Question 7

Breeding value

Answer 7

The value of an individual as a (genetic) parent

Question 8

Independent Gene Effect

Answer 8

The effect of a gene independent of the effect of the other gene at the same locus (dominance) and the effects of genes at other loci (epistasis)

Question 9

Breeding Value

Answer 9

The part of an individual’s genotypic value that is due to independent and therefore transmittable gene effects.

Question 10

Estimated Breeding Value

Answer 10

A prediction of a breeding value

Question 11

Progeny Difference (PD) or Transmitting Ability (TA)

Answer 11

Half an individual’s breeding value- the expected difference between the mean performance of the individual’s progeny and the mean performance of all progeny (assuming randomly chosen mates)

Question 12

Expected Progeny Difference (EPD), Predicted Difference (PD), or Estimated Transmitting Ability (ETA)

Answer 12

A prediction of a progeny difference

Question 13

Additive Gene Effect

Answer 13

independent gene effect

Question 14

Additive Genetic Value or Additive Value

Answer 14

Breeding value

Question 15

Gene Combination Value (GCV)

Answer 15

The part of an individual’s genotypic value that is due to the effects f gene combinations (dominance and epistasis) and cannot, therefore, be transmitted from parent to offspring

Question 16

Gene Combination Effect

Answer 16

The effect of a combination of genes, i.e. a dominance or epistatic effect

Question 17

Nonadditive Gene Effects

Answer 17

Gene combination effects

Question 18

Nonadditive Genetic Value or Nonadditive Value

Answer 18

Gene combination value

Question 19

Repeated trait

Answer 19

A trait for which individuals commonly have more than one performance record.

Question 20

Producing Ability (PA)

Answer 20

The performance potential of an individual for a repeated trait.

Question 21

Permanent Environmental Effect

Answer 21

A environmental effect that permanently influences an individual’s performance for a repeated trait.

Question 22

Temporary Environmental Effect

Answer 22

An environmental effect that influences a single performance record of an individual, but does not permanently affect the individual’s performance potential for a repeated trait

Question 23

Most Probable Producing Ability (MPPA)

Answer 23

A prediction of producing ability

Question 24

Threshold

Answer 24

A point on the continuous liability scale for a threshold trait above which animals exhibit one phenotype and below which they exhibit another