Term 1

Recombinant

Definition 1

Term 2

Single Crossover

Definition 2

One point of crossover occurs between the selected point on the parent organism

Term 3

NCO

Definition 3

No Crossover occurs between the selected points on the parent organism strings
-

Term 4

Double Crossover

Definition 4

Two-point crossover where two points to be selected on the parent organism strings. Everything between the two points is swapped between the parent organisms, rendering two child organisms:

Term 5

Coefficient of coincidence

Definition 5

Ratio of observed double crossovers to expected crossovers

Term 6

Interference

Definition 6

Degree to which one crossover interferes with additional crossovers
-

Term 7

Mapping function

Definition 7

A function to relate the map distance to the recombination rate. Also takes into consideration that some multiple crossovers will be undetected. Takes into account all crossovers.

Term 8

Quantitative trait

Definition 8

Some measurement such as height, weight, yield (not eye color or ordinal numbers like number of bristles)

Term 9

Heritability

Definition 9

Proportion of phenotypic variation due to genetic differences
0 = no genetic variability
1 = no environmental variablilty
-

Term 10

Broad Sense Heritablity

Definition 10

Proportion of the phenotyic variance that can be attributed to genetic variance

Term 11

Narrow Sense Heritability

Definition 11

Proportion of the phenotypic variance that can be attributed to additive genetic variance

Term 12

Mass selection

Definition 12

Also truncation selection. A type of selection where we are interested in increasing some quantitative trait through selective breeding
-

Term 13

Selection Differential (SD)

Definition 13

The selection differential is the difference of the base population mean and the mean of the selected parents.
I x Sigma

Term 14

Selection Response (SR)

Definition 14

Difference in mean of original vs mean of offspring
H2SD

Term 15

Genotypic Array

Definition 15

Set of genomic frequencies
PAA+QAa+Raa
-

Term 16

Gametic Array

Definition 16

Set of allelic frequencies
pA+qa
p=P+1/2Q, q=R+1/2Q

Term 17

Homozygosity

Definition 17

Organism that possesses two identical alleles at a locus
-In regards to Hardy-Weinberg: Fraction of homozygotes in the population

Term 18

Heterozygosity

Definition 18

Organism that possesses two different alleles at a locus
-In regards to Hardy-Weinberg: Fraction of heterozygotes in the population
-

Term 19

Polymorphism

Definition 19

having multiple alleles of a gene within a population, usually expressing different phenotypes

Term 20

Hardy-Weinberg equilibrium

Definition 20

Important principle of population genetics stating that, in a large, randomly mating population not affected by mutation, migration, or natural selection, allelic frequencies will not change and genotype frequencies stabilize after one generation the proportion is p2, 2pq, q2, where p equals the frequency of allele A and q equals the frequency of allele a.
p2AA+2pqAa+p2aa

Term 21

Directional Selection

Definition 21

Selection in which one trait or allele is favored over another. Favored allele is eventually fixed in the population and the other is lost.
-

Term 22

Balancing Selection

Definition 22

All alleles remain in population but heterozygous fitness is greatest

Term 23

Dispersive Selection

Definition 23

Fitness of heterozygote is smaller than either of the homozygotes

Term 24

Overdominance

Definition 24

Selection in which the heterozygote has higher fitness than than of either homozygote; also called heterozygote advantage
-

Term 25

Underdominance

Definition 25

Selection in which the heterozygote has lower fitness than that of either homozygote

Term 26

Mean Fitness

Definition 26

The sum of the fitnesses of the genotypes of a population weighted by their proportions; hence a weighted mean fitness.

Term 27

Genetic Drift (Random Drift)

Definition 27

Change in allelic frequency due to sampling error
-

Term 28

Founder Population

Definition 28

Small population colonizing a new area.
-Small size
-Not representative of entire population
-Undergo Strong Selection

Term 29

Ploidy

Definition 29

is the number of complete sets of chromosomes in a biological cell.

Term 30

Euploidy

Definition 30

True copy number. Refers to mutations that involve excess or deficiency of all all all of the chromosome types
-

Term 31

Aneuploidy

Definition 31

Derived from a nondisjunction event within a single species. Normally infertile and have an odd number of copies of haploid number

Term 32

Nondisjunction

Definition 32

Failure of homologous chromosomes or sister chromatids to separate in meiosis or mitosis

Term 33

Autoreplication

Definition 33
-

Term 34

Duplication

Definition 34

Adding portions of the chromosome

Term 35

Deletion

Definition 35

Mutation in which one or more nucleotides are deleted from a DNA sequence

Term 36

Inversion

Definition 36

When the order of the DNA is rearranged form normal order on the chromosome
-

Term 37

Partial Monosomy

Definition 37

Monosomy refers to lack of one chromosome of the normal complement. Partial monosomy can occur in unbalanced translocations or deletions, in which only a portion of the chromosome is present in a single copy

Term 38

Partial Trisomy

Definition 38

Trisomy refers to the presence of three copies, instead of the normal two

Term 39

Autoploidy

Definition 39

Derived from a nondisjunction event within single species. Excess or deficiency in single chromosome
-

Term 40

Allopolyploidy

Definition 40

Having two or more complete sets of chromosomes derived from different species.

Term 41

Translocation

Definition 41

Movement of a chromosome segment to a nonhomologous chromosome or to a region within the same chromosome; also movement of a ribosome along mRNA in the course of translation

Term 42

Transposition

Definition 42

Movement of a transposable genetic element from one site to another. Replicative transposition increases the number of copies of the transposable element; nonreplicative transposition does not increase the number of copies
-

Term 43

Fusion

Definition 43

Where 2 chromosomes come together

Term 44

Fission

Definition 44

Where 2 Chromosomes split

Term 45

Behavior

Definition 45

Reaction of an organism to environmental stimuli
-

Term 46

Chemotaxis

Definition 46

is the phenomenon in which bodily cells, bacteria, and other single-cell or multicellular organisms direct their movements according to certain chemicals in their environment.

Term 47

Phototaxis

Definition 47

occurs when a whole organism moves in response to the stimulus light.

Term 48

Environmental Bias

Definition 48

Example: Fish in streams inevitably face upstream
-

Term 49

Concordance

Definition 49

Percentage of twin pairs in which both twins have a particular trait

Term 50

Twin studies

Definition 50

Allows scientists to study human differences based on environment and genetics when they have itentical (monozygotic twins)genetics or are raised in same environment but have similar genes (monozygotic)

Term 51

Single gene behavioral traits

Definition 51

behavioral traits the are the result of single genes
Examples: Lesch-Nyhan Disease, Fragile X, Hygienic Bees
-

Term 52

Threshold trait

Definition 52

A trait that falls into natural groups that originate not in categorically distinct causes but in whether or not the outcome attains critical values; e.g., gallstones may result from a categorical cause or from unusual levels of causal factors that themselves show no evidence of grouping.

Term 53

comparative studies

Definition 53

studying breeds/species with extreme traits often helps us to understand behavioral traits

Term 54

Plasticity

Definition 54
-

Term 55

Selection Intensity

Definition 55

Variable in Mass selection equations (I)
Given for proportion

Term 56

Standardized Selection Point

Definition 56

Value in Mass selection equations (Z)
Given for proportion
Z=(x-mu)/sigma

Term 57

Mean

Definition 57

Mu
-

Term 58

Standard Deviation

Definition 58

Sigma

Term 59

Proportion selected

Definition 59

p

Term 60

Assortative Mating

Definition 60

When mates are chosen based on the similarity of their phenotypes. Results in an increase in homozygosity
-

Term 61

Pericentric Inversion

Definition 61

Includes centrosome