Breeding and Genetics Terminologies

Question 1

Reappearance of a character after it has not appeared for one or more generations.

Answer 1

Atavism

Question 2

crossing of F1 offspring with either parental breeds.

Answer 2

Backcross

Question 3

refers to a deep, wide and low-set animals

Answer 3

Blocky

Question 4

a donkey or a ass

Answer 4

Burro

Question 5

The number or percentage of calves produced in a herd within a year.

Answer 5

Calf Crop

Question 6

Chromosomes other than sex chromosomes.

Answer 6

Autosomes

Question 7

crossbred between American bison and domestic cattle.

Answer 7

Cattalo (Catalo)

Question 8

exchange of parts of homologous chromosomes during meiosis.

Answer 8

Crossing Over

Question 9

interaction of two or more pairs of genes that are not alleles to produce a phenotype that they don’t produce when they occur separately.

Answer 9

Epistasis

Question 10

an estimate of the proportion of the total phenotypic variation in a population that is due to heredity.

Answer 10

Heritability Estimate

Question 11

chromosomes of a plant or animals that at metaphase stage of cell division.

Answer 11

Karyotype

Question 12

region of chromosomes or pairs of homologous chromosomes where a particular gene is located.

Answer 12

Locus

Question 13

a series of more than two alleles which occupy the same location in a homologous chromosomes.

Answer 13

Multiple Alleles

Question 14

The production of progeny that are superior to the parents which produce them.

Answer 14

Nicking

Question 15

a chemical compound composed of a nitrogen base, a sugar and phosphate molecule.

Answer 15

Nucleotide

Question 16

females that never give birth to a young.

Answer 16

Nulliparous

Question 17

mating of an individual to another within the same breed which is not closely related to it.

Answer 17

Outcross

Question 18

interaction of the members of a pair of genes to produce a phenotype more superior in heterozygote that either homozygote.

Answer 18

Overdominance

Question 19

production of a particular phenotype by environment that is also produced by heredity.

Answer 19

Phenocopy

Question 20

a situation where one gene affects two or more traits.

Answer 20

Pleitrophy

Question 21

a trait determined by many pairs of genes.

Answer 21

Polygenic Inheritance

Question 22

cryptorchid

Answer 22

Rigling

Question 23

coming together of paired chromosomes during first meiotic division.

Answer 23

Synapsis

Question 24

a test to determine if the individual is s carrier or recessive gene.

Answer 24

Test Cross

Question 25

amount of variation within a population.

Answer 25

Variance

Question 26

the cell material which acts as the means for transporting genes during cell division.

Answer 26

Chromosomes

Question 27

The units or factors of heredity that are responsible for the expression of any characteristic.

Answer 27

Genes

Question 28

The science or study of heredity and variation.

Answer 28

Genetics

Question 29

The differences in genetic makeup that exist among animals.

Answer 29

Genetic Variation

Question 30

Practice of mating animals more closely related than the average of the population. Examples: full brother to sister, sire to daughter, or son to dam.

Answer 30

Inbreeding

Question 31

A gene which causes the death of the animal, usually before or at birth. Most gene pairs causing inherited lethals must be in the homozygous (pure) recessive condition to be fatal.

Answer 31

Lethal Gene

Question 32

A mild form of inbreeding. Usually practiced to maintain as high a relationship as possible to some outstanding ancestor.

Answer 32

Linebreeding

Question 33

Length of useful life.

Answer 33

Longevity

Question 34

The ability of a gene or group of genes to cause their characteristic to develop under the conditions of a particular environment.

Answer 34

Penetrance

Question 35

The degree to which character is maintained during longevity.

Answer 35

Persistency

Question 36

Estimate of genetic superiority (or inferiority) that an animal will transmit to an offspring.

Answer 36

Predicted Transmitting Ability (PTA)

Question 37

The evaluation of an animal based upon the performance or appearance of its offspring.

Answer 37

Progeny Test

Question 38

different versions of the same gene

Answer 38

Alleles

Question 39

two alleles that have different effects that are distinguishable in a heterozygous individual (e.g. AB blood groups)

Answer 39

Codominant Alleles

Question 40

crossing two different breeds.

Answer 40

Crossbreeding

Question 41

one that determines the phenotype even when there is only one copy (i.e. in a heterozygous individual).

Answer 41

Dominant Allele

Question 42

changes in allele frequencies over time due to chance (as opposed to selection or mutation).

Answer 42

Drift

Question 43

used to describe the situation where one gene's expression prevents the expression of another.

Answer 43

Epistasis

Question 44

loss of all alleles of a gene.

Answer 44

Fixation

Question 45

loss of alleles due to genetic drift.

Answer 45

Gene Dropping

Question 46

when population numbers are temporarily reduced to a level insufficient to maintain the diversity in the population.

Answer 46

Genetic Bottleneck

Question 47

usually expressed in terms of percentage of genes that are polymorphic and/or are heterozygous.

Answer 47

Genetic Diversity

Question 48

the total genetic makeup of an organism.

Answer 48

Genome

Question 49

carrying two different alleles of a gene.

Answer 49

Heterozygous

Question 50

a situation where the heterozygous genotype for a particular gene shows the highest relative fitness.

Answer 50

Heterozygous Advantage

Question 51

when the heterozygous genotype lacks sufficient gene product to have the normal phenotype.

Answer 51

Heterozygous Inssuficiency

Question 52

a situation where crossing two inbred lines yields progeny that are more healthy/vigorous than their parents.

Answer 52

Heterosis

Question 53

a measure of how frequently two genes found on the same chromosome remain together during gamete (egg or sperm) formation.

Answer 53

Linkage

Question 54

the fraction of all the alleles of a gene in a population that are of one type

Answer 54

Allele Frequency

Question 55

mating two individuals of the same breed that are sufficiently unrelated.

Answer 55

Outcrossing

Question 56

the reciprocal exchange of portions of two homologous chromosomes during gamete formation.

Answer 56

Recombination

Question 57

(found at the same locus in homologous chromosomes that may produce different phenotype)

Answer 57

Alleles

Question 58

(Approximately equivalent to partial dominance.)

Answer 58

Heterozygous Insufficiency

Question 59

More commonly used in plant breeding

Answer 59

Heterosis