Midterm 1 terms Flashcards
1
Q
Trait
A
any observable or measurable characteristic of an individual
2
Q
Phenotype
A
an observed category or measured level of performance for a trait in an individual
3
Q
Genotype
A
the genetic makeup of an individual
4
Q
Environmental effect
A
the effect that external (non-genetic) factors have on animal performance
5
Q
Seed stock
A
breeding stock, animals whose role it is to be a parent, or in other words, to contribute genes to the next generation
6
Q
Population
A
a group of inter-mating individuals. The term can refer to a breed, an entire species, a single herd or flock, or even a small group of animals within a herd
7
Q
Selection
A
8
Q
Natural selection
A
selection that occurs in nature independent of deliberate human control
9
Q
Artificial selection
A
selection that is under human control
10
Q
Breeding values (BV)
A
the value of an individual as a genetic parent
11
Q
Genotype by environment interactions
A
a dependent relationship between genotypes and environments in which the difference in performance between 2 (or more) genotypes changes from environment to environment
12
Q
Breeding objective
A
a general goal for a breeding program; a notion of what constitutes the ‘best’ animal
13
Q
heritability
A
a measure of the strength of the relationship between breeding values and phenotypic values for a trait in a population
14
Q
dam
A
a female parent
15
Q
sire
A
a male parent
16
Q
pedigree data
A
information on the genotype or performance of ancestors and (or) collateral relatives of an individual
17
Q
progeny data
A
information on the genotype or performance of descendents of an individual
18
Q
polygenic trait
A
a trait affected by many genes, no single gene having an overriding influence
19
Q
simply-inherited trait
A
a trait affected by only a few genes
20
Q
mating
A
the process that determines which (selected) males are bred to which (selected) females
21
Q
hybrid vigour
A
aka heterosis; an increase in the performance of hybrids over that of purebreds; most noticeably in traits like fertility and survivability
22
Q
hybrid
A
an individual that is a combination of species, breeds with in species, or lines within species
23
Q
inbreeding
A
the mating of relatives
24
Q
gene
A
the physical unit of heredity consisting of a DNA sequence at a specific location on a chromosome
25
DNA
deoxyribonucleic acid; the molecule that forms the genetic code
26
chromosome
one of a # of long strands of DNA and associated proteins present in the nucleus of every cell
27
homolog
one of a pair of chromosomes having corresponding loci
28
locus
the specific location of a gene on a chromosome
29
allele
an alternative form of a gene
30
genotype
the combination of genes at a single locus or at a number of loci
31
segregation
the separation of paired genes during germ cell formation
32
meiosis
the process of germ cell formation
33
independent assortment
the independent segregation of genes at different loci
34
linkage
the occurance of 2 or more loci of interest on the same chromosome
35
crossing over
a reciprocal exchange of chromosome segments between homologs. Crossing over occurs during meiosis prior to the time homologous chromosomes are separated to form gametes
36
embryo
an organism in the early stages of development
37
zygote
a cell formed from the union of male and female gametes. A zygote has a full complement of genes- half from the sperm and half from the egg
38
dominance
an interaction between genes at a single locus such that in heterozygotes one allele has more effect than the other. The allele with greater affect is said to be dominant over its recessive counterpart
39
complete dominance
a form of dominance in which the expression of the heterozygote is identical to the expression of the homozygous dominant genotype
40
partial dominance
a form of dominance in which the expression of the heterozygote is intermediate to the expressions of the homozygous genotypes and more closely resembles the expression of the homozygous dominant genotype
41
no dominance
a form of dominance in which the expression of the heterozygote is exactly midway between the expressions of the homo genos
42
overdominance
a form of dominance in which the expression of the heterozygote is outside the range defined by the expressions of the homozygous genotypes and most closely resembles the expression of the homozygous dominant genotype
43
epistasis
an interection among genes at different loci such that the expression of genes at one locus depends on the alleles present at one or more other loci
44
sex linkage or sex linked inheritance
the pattern of inheritance for genes located on sex chromosomes
45
hemizygous
having only one gene of a pair. eg- a gene on the x chromosome of a mammalian male
46
sex limited inheritance
a pattern of inheritance in which phenotypic expression is limited to one sex
47
sex influenced inheritance
a pattern of inheritance in which modes of gene expression differ between males and females. eg- an allele may be dominant in males and recessive in females
48
gene frequency
aka- allelic frequency; the relative frequency of a particular allele in a population
49
genotypic frequency
the relative frequency of a particular one locus genotype in a population
50
outbreeding
the mating of unrelated individuals; increases heterozygosity, complementarity of animals; hybrid vigor (heterosis)
51
hardy weinberg equilibrium
a state of constant gene and genotypic frequencies occuring in a population in the absence of forces that change those frquencies
52
mutation
the process that alters DNA to create new alleles
53
migration
the movement of individuals into or out of a population
54
random drift
change in gene frequencies in small populations due purely to chance
55
random mating
a mating system in which all matings are equally likely
56
qualitative or categorical trait
a trait in which phenotypes are expressed in categories
57
quantitative trait
a trait in which phenotypes show continuous (numerical) expression
58
dystocia
difficulty in giving birth or being born
59
threshold trait
a polygenic trait in which phenotypes are expressed in categories
60
test mating/cross
a mating designed to reveal the genotype of an individual for a small number of loci
61
fitness
the ability of an individual and its corresponding phenotype and genotype to contribute offspring to the next generation. The term refers to the number of offspring an individual produces- not just its ability to be selected
62
quantitative genetics
the branch of genetics concerned with influences on, measurement of, relationships amoung, genetic prediction for, and rate of change in traits that are or can be treated as quantitative
63
phenotypic value (P)
a measure of performance for a trait in an individual- a performance record
64
population mean (mu)
the average phenotypic value of all individuals in a population
65
genotypic value (G)
the effect of an individual's genes (singly and in combination) on its performance for a trait
66
environmental effect (E)
the effect that external (nongenetic) factors have on animal performance
67
breeding value (BV)
the value of an individual as a genetic parent
68
independent gene effect
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)
69
BV
the part of an individual's genotypic value that is due to independent and therefore transmittable gene effects
70
estimated breeding value (EBV)
a prediction of a breeding value
71
Progeny difference (PD) or Transmitting ability (TA)
half an individuals breeding value- the expected difference between the mean performance of the individuals progeny and the mean performance of all progeny (assuming randomly chosen mates)
PD= 1/2 BV
72
expected progeny difference (EPD, predicted difference (PD), or estimated transmitting ability (ETA)
a prediction of a progeny difference
73
additive gene effect
independent gene effect
74
additive genetic value or additive value
breeding value
75
gene combination value (GCV)
the part of an individuals genotypic value that is due to the effects of gene combinations (dominance and epistasis) and therefore cannot be transmitted from parent to offspring
76
gene combination effect
the effect of a combination of genes; i.e- a dominance or epistatic effect
77
non additive gene effects
gene combination effects
78
non additive genetic value or non additive value
gene combination value
79
repeated trait
a trait for which individuals commonly have more than one performance record
80
producing ability (PA)
the performance potential of an individual for a repeated trait
81
permanent environmental effect (Ep)
an environmental effect that permanently influences an individuals performance for a repeated trait
82
most probable producing ability (MPPA)
a prediction of producing ability
83
temporary environmental effect (Et)
an environmental effect that influences a single performance record of an individual, but does not permanently affect the individuals performance potential for a repeated trait
84
threshold
a point on the continuous liability scale for a threshold trait above which animals exhibit one phenotype and below which they exhibit another
85
narrowsense heritablity
a measure of the strength of the relationship between performance (phenotypic values) and breeding values for a trait in a population
86
broadsense heritability
a measure of the strength of the relationship between performance (phenotypic values) and genotypic values for a trait in a population
87
contemporary group
a group of animals that have experienced a similar environment with respect to the expression of a trait. Contemporaries typically perform in the same location, are of the same sex, are of similar age, and have been managed alike
88
contempory group effect (Ecg)
an environmental effect common to all members of a contempory group
89
trait ratio
an expression of relative performance- the ratio of an individuals performance to the average performance of all animals in the individuals contempory group
90
91
any observable or measurable characteristic of an individual
Trait
92
an observed category or measured level of performance for a trait in an individual
Phenotype
93
the genetic makeup of an individual
Genotype
94
the effect that external (non-genetic) factors have on animal performance
Environmental effect
95
breeding stock, animals whose role it is to be a parent, or in other words, to contribute genes to the next generation
Seed stock
96
a group of inter-mating individuals. The term can refer to a breed, an entire species, a single herd or flock, or even a small group of animals within a herd
Population
97
Selection
98
selection that occurs in nature independent of deliberate human control
Natural selection
99
selection that is under human control
Artificial selection
100
the value of an individual as a genetic parent
Breeding values (BV)
101
a dependent relationship between genotypes and environments in which the difference in performance between 2 (or more) genotypes changes from environment to environment
Genotype by environment interactions
102
a general goal for a breeding program; a notion of what constitutes the 'best' animal
Breeding objective
103
a measure of the strength of the relationship between breeding values and phenotypic values for a trait in a population
heritability
104
a female parent
dam
105
a male parent
sire
106
information on the genotype or performance of ancestors and (or) collateral relatives of an individual
pedigree data
107
information on the genotype or performance of descendents of an individual
progeny data
108
a trait affected by many genes, no single gene having an overriding influence
polygenic trait
109
a trait affected by only a few genes
simply-inherited trait
110
the process that determines which (selected) males are bred to which (selected) females
mating
111
aka heterosis; an increase in the performance of hybrids over that of purebreds; most noticeably in traits like fertility and survivability
hybrid vigour
112
an individual that is a combination of species, breeds with in species, or lines within species
hybrid
113
the mating of relatives
inbreeding
114
the physical unit of heredity consisting of a DNA sequence at a specific location on a chromosome
gene
115
deoxyribonucleic acid; the molecule that forms the genetic code
DNA
116
one of a # of long strands of DNA and associated proteins present in the nucleus of every cell
chromosome
117
one of a pair of chromosomes having corresponding loci
homolog
118
the specific location of a gene on a chromosome
locus
119
an alternative form of a gene
allele
120
the combination of genes at a single locus or at a number of loci
genotype
121
the separation of paired genes during germ cell formation
segregation
122
the process of germ cell formation
meiosis
123
the independent segregation of genes at different loci
independent assortment
124
the occurance of 2 or more loci of interest on the same chromosome
linkage
125
a reciprocal exchange of chromosome segments between homologs. Crossing over occurs during meiosis prior to the time homologous chromosomes are separated to form gametes
crossing over
126
an organism in the early stages of development
embryo
127
a cell formed from the union of male and female gametes. A zygote has a full complement of genes- half from the sperm and half from the egg
zygote
128
an interaction between genes at a single locus such that in heterozygotes one allele has more effect than the other. The allele with greater affect is said to be dominant over its recessive counterpart
dominance
129
a form of dominance in which the expression of the heterozygote is identical to the expression of the homozygous dominant genotype
complete dominance
130
a form of dominance in which the expression of the heterozygote is intermediate to the expressions of the homozygous genotypes and more closely resembles the expression of the homozygous dominant genotype
partial dominance
131
a form of dominance in which the expression of the heterozygote is exactly midway between the expressions of the homo genos
no dominance
132
a form of dominance in which the expression of the heterozygote is outside the range defined by the expressions of the homozygous genotypes and most closely resembles the expression of the homozygous dominant genotype
overdominance
133
an interection among genes at different loci such that the expression of genes at one locus depends on the alleles present at one or more other loci
epistasis
134
the pattern of inheritance for genes located on sex chromosomes
sex linkage or sex linked inheritance
135
having only one gene of a pair. eg- a gene on the x chromosome of a mammalian male
hemizygous
136
a pattern of inheritance in which phenotypic expression is limited to one sex
sex limited inheritance
137
a pattern of inheritance in which modes of gene expression differ between males and females. eg- an allele may be dominant in males and recessive in females
sex influenced inheritance
138
aka- allelic frequency; the relative frequency of a particular allele in a population
gene frequency
139
the relative frequency of a particular one locus genotype in a population
genotypic frequency
140
the mating of unrelated individuals; increases heterozygosity, complementarity of animals; hybrid vigor (heterosis)
outbreeding
141
a state of constant gene and genotypic frequencies occuring in a population in the absence of forces that change those frquencies
hardy weinberg equilibrium
142
the process that alters DNA to create new alleles
mutation
143
the movement of individuals into or out of a population
migration
144
change in gene frequencies in small populations due purely to chance
random drift
145
a mating system in which all matings are equally likely
random mating
146
a trait in which phenotypes are expressed in categories
qualitative or categorical trait
147
a trait in which phenotypes show continuous (numerical) expression
quantitative trait
148
difficulty in giving birth or being born
dystocia
149
a polygenic trait in which phenotypes are expressed in categories
threshold trait
150
a mating designed to reveal the genotype of an individual for a small number of loci
test mating/cross
151
the ability of an individual and its corresponding phenotype and genotype to contribute offspring to the next generation. The term refers to the number of offspring an individual produces- not just its ability to be selected
fitness
152
the branch of genetics concerned with influences on, measurement of, relationships amoung, genetic prediction for, and rate of change in traits that are or can be treated as quantitative
quantitative genetics
153
a measure of performance for a trait in an individual- a performance record
phenotypic value (P)
154
the average phenotypic value of all individuals in a population
population mean (mu)
155
the effect of an individual's genes (singly and in combination) on its performance for a trait
genotypic value (G)
156
the effect that external (nongenetic) factors have on animal performance
environmental effect (E)
157
the value of an individual as a genetic parent
breeding value (BV)
158
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)
independent gene effect
159
the part of an individual's genotypic value that is due to independent and therefore transmittable gene effects
BV
160
a prediction of a breeding value
estimated breeding value (EBV)
161
half an individuals breeding value- the expected difference between the mean performance of the individuals progeny and the mean performance of all progeny (assuming randomly chosen mates)
PD= 1/2 BV
Progeny difference (PD) or Transmitting ability (TA)
162
a prediction of a progeny difference
expected progeny difference (EPD, predicted difference (PD), or estimated transmitting ability (ETA)
163
independent gene effect
additive gene effect
164
breeding value
additive genetic value or additive value
165
the part of an individuals genotypic value that is due to the effects of gene combinations (dominance and epistasis) and therefore cannot be transmitted from parent to offspring
gene combination value (GCV)
166
the effect of a combination of genes; i.e- a dominance or epistatic effect
gene combination effect
167
gene combination effects
non additive gene effects
168
gene combination value
non additive genetic value or non additive value
169
a trait for which individuals commonly have more than one performance record
repeated trait
170
the performance potential of an individual for a repeated trait
producing ability (PA)
171
an environmental effect that permanently influences an individuals performance for a repeated trait
permanent environmental effect (Ep)
172
a prediction of producing ability
most probable producing ability (MPPA)
173
an environmental effect that influences a single performance record of an individual, but does not permanently affect the individuals performance potential for a repeated trait
temporary environmental effect (Et)
174
a point on the continuous liability scale for a threshold trait above which animals exhibit one phenotype and below which they exhibit another
threshold
175
a measure of the strength of the relationship between performance (phenotypic values) and breeding values for a trait in a population
narrowsense heritablity
176
a measure of the strength of the relationship between performance (phenotypic values) and genotypic values for a trait in a population
broadsense heritability
177
a group of animals that have experienced a similar environment with respect to the expression of a trait. Contemporaries typically perform in the same location, are of the same sex, are of similar age, and have been managed alike
contemporary group
178
an environmental effect common to all members of a contempory group
contempory group effect (Ecg)
179
an expression of relative performance- the ratio of an individuals performance to the average performance of all animals in the individuals contempory group
trait ratio
180
