Definition of common animal genetics/breeding terms

Question 1

— Adaptation traits contribute to individual fitness and to the evolution of
animal genetic resources

Answer 1

Adaptation traits

Question 2

— The effect of an allele on animal performance, independent of the
effect of the other allele at a locus.

Answer 2

Additive genetic effects

Question 3

— One of a pair, or series of alternative forms of a gene that can occur at a given locus
on homologous chromosomes.

Answer 3

Allele

Question 4

 — Any one of a class of organic compounds containing the amino (NH2) group and
the carboxyl (COOH) group. Amino acids are combined to form proteins.

Answer 4

Amino acids

Question 5

— A system for genetic evaluations that estimates breeding values of individual
animals (males, females) at the same time. The system uses production data on all known
relatives in calculating a genetic evaluation

Answer 5

Animal model

Question 6

— Any individual from which an animal is descended.

Answer 6

Ancestor

Question 7

— Any chromosome that is not a sex chromosome

Answer 7

Autosome

Question 8

— The cross produced by mating a first-cross animal back to one of its parent lines
or breeds

Answer 8

Backcross

Question 9

— Either a sub-specific group of domestic livestock with definable and identifiable
external characteristics that enable it to be separated by visual appraisal from other similarly
defined groups within the same species, or a group for which geographical and/or cultural
separation from phenotypically similar groups has led to acceptance of its separate identity

Answer 9

Breed

Question 10

— The mean genetic value of an individual as a parent. It can be estimated as
the average superiority of an individual’s progeny relative to all other progeny under
conditions of random mating.

Answer 10

Breeding value

Question 11

— Spindle-fiber attachment region of a chromosome.

Answer 11

Centromere

Question 12

— Microscopically observable linear arrangement of DNA in the nucleus of a cell.

Answer 12

Chromosome

Question 13

— Alleles, each of which produces an independent effect in heterozygotes

Answer 13

Co-dominant alleles

Question 14

The mean performance of a line when involved in a cross-breeding system.

Answer 14

Combining ability —

Question 15

A line that is randomly selected and randomly mated. Usually used in selection
experiments to monitor environment effects in order to estimate genetic change in a selected
line.

Answer 15

Control line —

Question 16

— Matings between animals of different breeds or lines

Answer 16

Crossbreeding

Question 17

— The protoplasm outside a cell nucleus.

Answer 17

Cytoplasm

Question 18

— An individual descended from other individuals.

Answer 18

Descendant

Question 19

— Deoxyribonucleic acid, the chemical material which carries information to code for a
gene.

Answer 19

DNA

Question 20

— Applied to one member of an allelic pair of genes, which has the ability to express
itself wholly or largely at the exclusion of the expression of the other allele

Answer 20

Dominant

Question 21

— The aggregate of all the external conditions and influences affecting the life
and development of the organism.

Answer 21

Environment

Question 22

— A prediction of a breeding value. See breeding value

Answer 22

Estimated breeding value

Question 23

— When the gene at one locus affect the expression of the gene at another locus

Answer 23

Epistasis

Question 24

— A sequence of DNA that is expressed (transcribed) into RNA , then translated into
protein.

Answer 24

Exon

Question 25

— Animals resulting from crossing parents from different lines or breed

Answer 25

F1

Question 26

— Animals resulting from matings among F1 parents

Answer 26

F2

Question 27

— Animals resulting from matings among F2 parents

Answer 27

F3

Question 28

The mean number of offspring per parent that successfully reproduce

Answer 28

Family size —

Question 29

— Individuals having the same male and female parents

Answer 29

Full sibs

Question 30

— A sperm or egg cell containing the haploid (1n) number of chromosomes .

Answer 30

Gamete

Question 31

— A functional hereditary unit that occupies a fixed location on a chromosom

Answer 31

Gene

Question 32

 — A gene or DNA sequence having a known location on a chromosome and associated with a particular gene or trait; a gene phenotypically associated with a particular, easily identified trait and used to identify an individual or cell carrying that gene.

Answer 32

Genetic marker

Question 33

— Variation in phenotype which results from variations in genetic composition among individuals.

Answer 33

Genetic variance

Question 34

— The complete set of genes and non-coding sequences present in each cell of an organism, or the genes in a complete haploid set of chromosomes of a particular organism.

Answer 34

Genome

Question 35

— A discipline in genetics concerned with the study of the genome of an organism.

Answer 35

Genomics

Question 36

— The genetic constitution of one or a few gene(s) or locus (loci), or total genetic make-up (genes) of an individual organism.

Answer 36

Genotype

Question 37

— The process of repeated backcrossing to one parental line to produce a population that is nearly purebred.

Answer 37

Grade-up

Question 38

Individuals that share only one common parent

Answer 38

Half sibs —

Question 39

— A set of alleles at a closely linked group of loci, so closely linked that the allelic set behaves almost as one allele in terms of inheritance

Answer 39

Haplotype

Question 40

— Degree to which a given trait is controlled by inheritance; proportion of total phenotypic variation that is attributable to genetic variation (in contrast to environmentcaused variation).

Answer 40

Heritability

Question 41

— The degree to which the performance of a crossbred animal is better or worse than the average performance of the parents.

Answer 41

Heterosis

Question 42

An organism with unlike members of any given pair or series of alleles, which consequently produces unlike gametes

Answer 42

Heterozygote, adj. heterozygous —

Question 43

— Chromosomes which occur in pairs and are similar in size and shape, one having come from the male and one from the female parent.

Answer 43

Homologous chromosomes

Question 44

— An organism whose chromosomes carry identical members of a given pair of genes. The gametes are therefore all alike with respect to this locus

Answer 44

Homozygote, adj. homozygous

Question 45

— Matings among related individuals, which results in progeny that have less heterozygosity and hence more homozygous gene pairs than the average of the population.

Answer 45

Inbreeding

Question 46

— When animals are culled if they do not meet all of the minimum levels of performance for a set of traits.

Answer 46

Independent culling

Question 47

— The appearance of the metaphase chromosomes of an individual or species, which shows the comparative size, shape, and morphology of the different chromosomes.

Answer 47

Karyotype

Question 48

— A gene that results in the death of the animal.

Answer 48

Lethal gene

Question 49

— Both internal (e.g., genetic merit) and external (e.g., nutrition, disease, exposure) forces that influence the expression of a threshold character (e.g., disease, conception, abnormalities, etc.).

Answer 49

Liability

Question 50

— Mating of selected individuals from successive generations to produce animals with a high relationship to one or more selected ancestors. It is a mild form of inbreeding

Answer 50

Line-breeding

Question 51

— Association of genes physically located on the same chromosome. A group of linked genes is called a linkage group.

Answer 51

Linkage

Question 52

— The advantage of the crossbred mother over the average of purebred mothers.

Answer 52

Maternal heterosis

Question 53

— The rules which describe how selected breeds and/or individuals will be paired at mating.

Answer 53

Mating systems

Question 54

— The process by which the chromosome number of a reproductive cell becomes reduced to half the diploid (2n) or somatic number and results in the formation of eggs or sperm.

Answer 54

Meiosis

Question 55

— Movement of animals, and consequently genes, from one population to another.

Answer 55

Migration

Question 56

 — Refers to the frequency at which the less common allele occurs in a given population.

Answer 56

Minor allele frequency (MAF)

Question 57

— Small bodies in the cytoplasm of most plant and animal cells responsible for energy production.

Answer 57

Mitochondria

Question 58

— Cell division process in which there is first a duplication of chromosomes, followed by migration of chromosomes to the ends of the spindle and a dividing of the cytoplasm, resulting in the formation of two cells with diploid (2n) number of chromosomes.

Answer 58

Mitosis

Question 59

 — The branch of genetic studies that deals with hereditary transmission and variation on the molecular level. It deals with the expression of genes by studying the DNA sequences of chromosomes.

Answer 59

Molecular genetics

Question 60

— Three or more alternative forms of a gene representing the same locus in a given pair of chromosomes

Answer 60

Multiple alleles

Question 61

— A sudden change in the genotype of an organism. The term is most often used in reference to point mutations (changes in base sequence within a gene), but can refer to chromosomal changes

Answer 61

Mutation

Question 62

— Natural processes favoring reproduction by individuals that are better adapted, and tending to eliminate those less adapted to their environment.

Answer 62

Natural selection

Question 63

— Part of a cell containing chromosomes and surrounded by cytoplasm

Answer 63

Nucleus

Question 64

— Mating of individuals that are less closely related than the average of the

Answer 64

Outcrossing

Question 65

— Usually refers to pedigree chart or what a

Answer 65

Pedigree

Question 66

— The proportion of the individuals with a particular gene combination that express the corresponding trait.

Answer 66

Penetrance

Question 67

— Environmental effects that result in permanent effects on the phenotypic expression of a trait.

Answer 67

Permanent environmental effects

Question 68

— Genetically determined characteristic which can be possessed by an organism. A synonym of trait.

Answer 68

Phene

Question 69

— The set of all phenotypes expressed by a cell, tissue, organ, organism, or species

Answer 69

Phenome

Question 70

— Actual exhibit of observable traits. Normally, it refers to physical characteristic of an individual such as size, shape, color, or performance.

Answer 70

Phenotype

Question 71

— When two traits tend to change in the same or different direction as a net result of genetic and environmental effects.

Answer 71

Phenotypic correlation

Question 72

— A performance record; a measure of an animal's performance for a trait.

Answer 72

Phenotypic value

Question 73

— Variation in phenotype which results from variation in genetic and environmental effects on the individuals.

Answer 73

Phenotypic variation

Question 74

— Where DNA or genes have more than two forms or alleles in the population

Answer 74

Polymorphism

Question 75

— Entire group of organisms of a kind that interbreed.

Answer 75

Population

Question 76

— The branch of genetics which deals with frequencies of alleles in groups of individuals.

Answer 76

Population genetics

Question 77

— Offspring or individuals resulting from specific matings.

Answer 77

Progeny

Question 78

— A test used to help predict an individual's breeding values, involving multiple matings of that individual and evaluation of its offspring.

Answer 78

Progeny test

Question 79

— Any of a group of complex nitrogenous organic compounds that contain amino acids as their basic structural units, occur in all living matter, and are essential for the growth and repair of animal tissue.

Answer 79

Protein

Question 80

— A trait that can generally be classified into a limited number of categories, and the animal can be said to "possess" the quality or not

Answer 80

Qualitative trait

Question 81

— A trait that is represented by an almost continuous distribution of measurements.

Answer 81

Quantitative trait

Question 82

) — A locus that affects a quantitative trait.

Answer 82

Quantitative trait locus (QTL

Question 83

— A mating system in which animals are assigned as breeding pairs at random, without regard to genetic relationship or performance.

Answer 83

Random mating

Question 84

— Applies to one member of an allelic pair which lacks the ability to manifest itself

Answer 84

Recessive

Question 85

— Ribonucleic acid, involved in the transcription of genetic information from DNA

Answer 85

RNA

Question 86

— The separation of paired alleles at loci during germ cell formation

Answer 86

Segregation

Question 87

— Any natural or artificial process favoring the survival and propagation of certain individuals in a population

Answer 87

Selection

Question 88

— The linear arrangement of nucleotides that make up unbranched polymer chains of DNA or RNA.

Answer 88

Sequence

Question 89

— The X or Y chromosomes

Answer 89

Sex chromosomes

Question 90

— A distinct variant of a phenotypic character of an org

Answer 90

Trait

Question 91

— The allele at a particular SNP that is the least frequent in a population

Answer 91

Variant allele

Question 92

— The cell produced by the union of mature gametes (egg and sperm) in reproduction

Answer 92

Zygote

Question 93

is the biology of heredity and variation that mainly deals with the way in which traits of the parents are passed on or transmitted to their offspring

Answer 93

Genetics

Question 94

is a branch of genetics, which is concerned with the proper selection and use of the traits of the parents to produce offspring with predictable and desirable traits for the improvement of animals in general.

Answer 94

Breeding