Exam 3 - Breeding And Biotechnology

Question 1

Molecular genetics

Answer 1

Structure and function of genes

Question 2

Applied genetics

Answer 2

Improving genetic outcomes for the benefit of the animals and/or humans

Question 3

Population genetics

Answer 3

Gene frequency within a population and how these frequencies influence genetics

Question 4

Quantitative

Answer 4

Can be measured numerically, continuous variable

Question 5

Qualitative

Answer 5

Can be described, expressed categorically, limited variables

Question 6

Quantitative traits are controlled by ______ genes while qualitative traits are controlled by ______ genes

Answer 6

Many; few

Question 7

Examples of quantitative

Answer 7

Milk yield, litter size, weaning weight, back fat thickness, eggs produced a year

Question 8

Qualitative trait examples

Answer 8

Wool color, horns, white udders in cattle living outside, coat color

Question 9

Heritability

Answer 9

The proportion of phenotypic variation that can be passed from parent to offspring

Question 10

Quantitative traits: __________ environmental influence, _________ heritability

Qualitative traits: __________ environmental influence, _________ heritability

Answer 10

Quantitative: greater; variable
Qualitative: less; greater

Question 11

Factors impacting genetic improvement of quantitative traits (3)

Answer 11

Heritability of trait, selection differential, generation interval

Question 12

Heritability of the trait

Answer 12

May be used to estimate the value of an individual -its ability to transmit desirable genes to the offspring, can be used to predict the rate of genetic progress

Question 13

Heritability

Answer 13

% of phenotypic variation among animals for a particular trait that is due to additive gene effects (not environment)

Question 14

Greater heritability =

Answer 14

Greater improvement

Question 15

Heritability range: 0-1
Highly heritable range:
Moderately heritable range:
Low heritability range:

Answer 15

Heritability range: 0-1
Highly heritable range: 0.4-0.6
Moderately heritable range: 0.2-0.4
Low heritability range: 0-0.2

Question 16

Highly heritable range

Answer 16

0.4-0.6

Question 17

Moderately heritable range

Answer 17

0.2-0.4

Question 18

Low heritability range

Answer 18

0-0.2

Question 19

Selection differential

Answer 19

Phenotypic advantage of the animal chosen to be parents in relation to the average for the population

Superiority compared to the herd average for a particular trait

Question 20

Genetic progress = _________ X ________

Answer 20

Selection differential X heritability

Question 21

Generation interval

Answer 21

Average age of the parents at the birth of their first offspring that in their turn will produce the next generation of breeding animals
How long it takes to pass along genetics

Question 22

How to calculate generation interval

Answer 22

(Average age of breeding females + average age of breeding males)
/2

Question 23

Limiting factor to generation interval

Answer 23

Breeding age of female

Question 24

Genetic change per year (annual rate of genetic progress) =

Answer 24

(Heritability X selection differential) / generation interval

Question 25

_______ and _______ are tools used to make genetic changes in a herd

Answer 25

Selection and mating

Question 26

Random mating

Answer 26

Selected animals mate at random (each male has opportunity to mate with each female)

Question 27

In-breeding

Answer 27

Intensive breeding of close relatives practiced to maintain breed standards and increases predictability of offspring because limited gene pool

Question 28

Inbreeding depression

Answer 28

After generations dominant traits can lose their vigor and have reduced survival and fertility of offspring of related individuals

Question 29

Challenges with in-breeding

Answer 29

Increased homozygosity, greater chance that detrimental genes will be expressed, decreased fitness/performance, inbreeding depression

Question 30

Line-breeding

Answer 30

Less restrictive than in-breeding, maintain high genetic relationship to a superior ancestor, useful when producer has difficulty finding superior genetics outside own herd

Question 31

Out-breeding

Answer 31

Mating of unrelated animals within lines and breeds or between breed

Question 32

Out-breeding has __________ effects in lowly heritable traits and within the _______ generation of crossbreeding

Answer 32

Greatest; first

Question 33

Outcrossing

Answer 33

Individual lines unrelated for at least 4-6 generations

Question 34

Crossbreeding

Answer 34

Mating animals of different breeds for breed complementation, utilize different breeds with strength in traits of interest

Question 35

Inbreeding: _______ variation _______ homozygosity Outbreeding: _______ variation _______ heterozygosity ________productivity through hybrid vigor

Answer 35

Inbreeding: decrease; increase Outbreeding: increase; increase; increase

Question 36

Heterosis/Hybrid vigor

Answer 36

Increased productivity of crossbred progeny above average of breeds or lines that are crossed

Question 37

Why chose hybrid vigor

Answer 37

Fewer unfavorable recessive genes expressed, favorable dominant genes are combined

Question 38

Hardy-Weinberg Equilibrium

Answer 38

In a large, randomly mated population, the absence of any evolutionary forces, gene frequencies will remain constant Does not usually happen in domesticated animal population

Question 39

Molecular genetics

Answer 39

Branch of genetic dealing with the structure and activity of genetic material at the molecular level

Question 40

Transgenic organisms

Answer 40

Purposeful manipulation of an organisms DNA to produce organisms with genomes that cannot be created through traditional breeding

Question 41

Transgenic organism examples

Answer 41

Production of pharmaceuticals, study of human disease, direct benefit to the animal (disease resistant), development of animal used to harvest organ transplant, protecting the environment

Question 42

Cloning

Answer 42

Process of producing a genetic copy of a DNA segment, gene, embryo or animal

Question 43

Types of cloning (3)

Answer 43

DNA cloning, reproductive cloning, therapeutic cloning (embryo cloning)

Question 44

DNA cloning

Answer 44

Generate multiple, identical, copies of DNA

Question 45

Reproductive cloning

Answer 45

Harvesting a cell from an animal and then transplanting the nucleus from that cell into an egg that has had the nucleus removed

Question 46

Therapeutic cloning (aka embryo cloning)

Answer 46

Production of embryos for use in research, with the goal of harvesting stem cells rather than creating cloned animals