Chapter 2 genes and prenatal development Flashcards
sausage-shaped structure in the nucleus of
cells, containing genes, which are paired,
except in reproductive cells
Chromosome
long strand of cell material that stores and
transfers genetic information in all life forms
DNA (deoxyribonucleic acid)
segment of DNA containing coded
instructions for the growth and functioning of
the organism
Gene
entire store of an organism’s hereditary
information
Genome
organism’s unique genetic inheritance
Genotype
organism’s actual characteristics, derived
from its genotype
phenotype
pattern of inheritance in which a pair of
chromosomes contains one dominant and one
recessive gene, but only the dominant gene is
expressed in the phenotype
Dominant-recessive inheritance
on a pair of chromosomes, each of two forms
of a gene
Allele
form of dominant–recessive inheritance in
which the phenotype is influenced primarily by
the dominant gene but also to some extent by
the recessive gene
incomplete dominance
expression of phenotypic characteristics due
to the interaction of multiple genes
polygenic inheritance
chromosomes that determine whether an
organism is male (XY) or female (XX)
sex chromosomes
pattern of inheritance in which a recessive
characteristic is expressed because it is
carried on the male’s X chromosome
X-linked inheritance
debate among scholars as to whether human
development is influenced mainly by genes
(nature) or environment (nurture)
nature vs nurture
field in the study of human development that
aims to identify the extent to which genes
influence behaviour, primarily by comparing
people who share different amounts of their
genes
behaviour genetics
twins who developed from a single ova and
sperm, and therefore have exactly the same
genotype; also called identical twins
monozygotic twins (MZ)
twins that result when two ova are released
by a female instead of one, and both are
fertilised by different sperm; also called
fraternal twins
dizygotic twins (DZ)
statistical estimate of the extent to which
genes are responsible for the differences
among people within a specific population,
with values ranging from 0 to 1.00
heritability
degree of similarity in phenotype among pairs
of family members, expressed as a
percentage
concordance rate
in development, the continuous bidirectional
interactions between genes and environment
epigenesis
range of possible developmental paths
established by genes; environment
determines where development takes place
within that range
reaction range
Three types of genotype-environment effects
Passive genotype
Evocative genotype
Active genotype
in the theory of genotype S environment
effects, the type that results from the fact
that in a biological family, parents provide
both genes and environment to their children
Passive genotype
in the theory of genotype → environment
effects, the type that results when a person’s
inherited characteristics evoke responses
from others in the environment
Evocative genotype
in the theory of genotype → environment
effects, the type that results when people
seek out environments that correspond to
their genotypic characteristics
Active genotype
