Active Gene-Environment Relation
A relationship between heredity and environment in which individuals actively seek
environments suitable to their genotype.
Active Interactions
The child actively seeks specific environments that are compatible with their
temperament, talent, or predisposition (sociable child wants to hang out in neighbourhood
park/ indoor playgrounds. Shy child prefers to play in the backyard)
Alleles
A specific form of a gene
Autosomes
The first 22 pairs of chromosomes that are not sex chromosomes
Behavioural Genetics
The study of the inheritance of the behavioural and psychological traits
Chromosomes
Organic structures in the cell’s nucleus that contain genetic material
Clinal variation
Continuous genetic variation observed between geographic regions
DNA
A molecule made up of chemical components, called nucleotide bases, which form a
code for specific genes
Dizygotic twins
(fraternal) biological siblings who developed from two separate eggs fertilized by two
separate sperm during the same incidence of fertilization
Dominant
An allele whose chemical instructions are always followed and expressed
Evocative gene-environment relation
A relationship between heredity and environment in which different genotypes evoke
different responses from the environment
Evocative Interactions
The child evokes particular responses from its parents and others based on its
genetically influenced behaviour. (a shy child may play alone, thus be left alone. Sociable child
demands more interactions, thus is given attention
Gamete
An egg or sperm cell
Gene
A group of chemical compounds, called nucleotide bases, which generates the
production of proteins or other important biological building blocks in the body
Genotype
The complete set of genes that make up a person’s heredity
Heterozygous
Having alleles of a gene that are different from each other
Homozygous
Having alleles of a gene that are identical to each other
Incomplete dominance
A genetic situation in which aspects of heterozygous alleles are both expressed
In vitro fertilization
An artificial form of egg fertilization in which egg and sperm are united in a laboratory
dish
Mainstreaming
An educational practice in which children with serious developmental disabilities are
placed in classrooms with children who do not have these types of disabilities
Meiosis
The biological process of cell division resulting in gametes that have 23 chromosomes,
which is half the amount of genetic material normally seen in a human cell
Mitosis
The biological process of cell division resulting in body cells that are exact copies of their
parent cells and have a full set of 46 chromosomes
Monozygotic twins
(identical) biological siblings who both developed from the same fertilized egg, which
split into two separate clusters, each of which formed into a separate but identical baby
Niche-picking
The process of deliberately selecting an environment suitable to one’s genotype
Nonshared environmental influences
Experiences and circumstances within a family that contribute to siblings being different
from each other
Passive gene-environment relation
A relationship between heredity and environment in which parents pass on genotypes
to children and also provide much of the early environment supporting expression of those
genes
Passive Interactions
Parents provide genotype and provide environmental enrichment supporting the
expression of those genes (musical child in a musical family)
Phenotype
A person’s genotype plus all other environmental influences that make up that person’s
physical, behavioural, and psychological characteristics
Polygenic Inheritance
The contribution of many genes to person’s phenotypic expression
Reaction range
The extent to which full genetic expression can occur, based on the limits imposed by
the environment
Recessive
An allele whose chemical instructions are ignored in the presence of a dominant allele
or expressed in the presence of another recessive allele
Sex chromosomes
The twenty third pair of chromosomes, which determines the gender of a person, XX for
female and XY for male