unit two - research methods Flashcards
the study of the relative power and limits of genetic and environmental influences on behavior.
behavior genetics
the genetic transfer of characteristics from parents to offspring.
heredity
every nongenetic influence, from prenatal nutrition to the people and things around us.
environment
threadlike structures made of DNA molecules that contain the genes.
chromosomes
a complex molecule containing the genetic information that makes up the chromosomes.
dna (deoxyribonucleic acid)
the biochemical units of heredity that make up the chromosomes; segments of DNA capable of synthesizing proteins.
genes
the complete instructions for making an organism, consisting of all the genetic material in that organism’s chromosomes.
genome
develop from a single fertilized egg that splits in two, creating two genetically identical organisms.
identical twins (monozygotic)
develop from separate fertilized eggs. They are genetically no closer than ordinary brothers and sisters, but they share a prenatal environment.
fraternal twins (dizygotic)
the proportion of variation among individuals in a group that we can attribute to genes. The heritability of a trait may vary, depending on the range of populations and environments studied.
heritability
the interplay that occurs when the effect of one factor (such as environment) depends on another factor (such as heredity).
interaction
the subfield of biology that studies the molecular structure and function of genes.
molecular genetics
the study of how the structure and function of genes interact with our environment to influence behavior.
molecular behavior genetics
“above” or “in addition to” (epi) genetics; the study of environmental influences on gene expression that occur without a DNA change.
epigenetics
the study of the evolution of behavior and the mind, using principles of natural selection.
evolutionary psychology
the principle that inherited traits that better enable an organism to survive and reproduce in a particular environment will (in competition with other trait variations) most likely be passed on to succeeding generations.
natural selection
a random error in gene replication that leads to a change.
mutation
a culturally modeled guide for how to act in various situations.
social script
a nerve cell; the basic building block of the nervous system.
neuron
the part of a neuron that contains the nucleus; the cell’s life support center.
cell body
a neuron’s often bushy, branching extensions that receive and integrate messages, conducting impulses toward the cell body.
dendrites
the neuron extension that passes messages through its branches to other neurons or to muscles or glands.
axon
a fatty tissue layer segmentally encasing the axons of some neurons; enables vastly greater transmission speed as neural impulses hop from one node to the next.
myelin sheath
cells in the nervous system that support, nourish, and protect neurons; they also play a role in learning, thinking, and memory.
glial cells (glia)
a neural impulse; a brief electrical charge that travels down an axon.
action potential
the level of stimulation required to trigger a neural impulse.
threshold