Chapter 3: Biology and Behavior Flashcards
alleles
two or more different forms of a gene
association areas
parts of the brain that lie between the major sensory and motor areas and that process and integrate input from those areas
axons
neural fibers that conduct electrical signals away from the cell body to connections with other neurons
behavior genetics
the science concerned with how variation in behavior and development results from the combination of genetic and environmental factors
cell body
a component of the neuron that contains the basic biological material that keeps the neuron functioning
cerebral cortex
the “grey matter” of the brain that plays a primary role in what is thought to be particularly humanlike functioning, from seeing and hearing to writing to feeling emotion
cerebral hemispheres
the two halves of the cortex; for the most part, sensory input from one side of the body goes to the opposite hemisphere of the brain
cerebral lateralization
the specialization of the hemispheres of the brain for different modes of processing
chromosomes
molecules of DNA that transmit genetic information; chromosomes are made up of DNA
corpus callosum
a dense tract of nerve fibers that enable the two hemispheres of the brain to communicate
crossing over
the process by which sections of DNA switch from one chromosome to the other; crossing over promotes variability among individuals
dendrites
neural fibers that receive input from other cells and conduct it toward the cell body in the form of electrical impulses
DNA (deoxyribonucleic acid)
molecules that carry all the biochemical instructions involved in the formation and functioning of an organism
dominant allele
the allele that, if present, gets expressed
environment
every aspect of an individual and his or her surroundings other than genes
event-related potentials (ERPs)
changes in the brain’s electrical activity that occur in response to the presentation of a particular stimulus
experience-dependent plasticity
the process through which neural connections are created and reorganized throughout life as a function of an individual’s experiences
experience-expectant plasticity
the process through which the normal wiring of the brain occurs in part as a result of experiences that every human who inhabits any reasonably normal environment will have
failure to thrive (nonorganic)
a condition in which infants become malnourished and fail to grow or gain weight for no obvious medical reason
frontal lobe
associated with organizing behavior; the one that is thought responsible for the human ability to plan ahead
genes
sections of chromosomes that are the basic unit of heredity in all living things
genome
the complete set of genes of any organism
genotype
the genetic material an individual inherits
glial cells
cells in the brain that provide a variety of critical supportive functions
heritability
a statistical estimate of the proportion of the measured variance on a trait among individuals in a given population that is attributable to genetic differences among those individuals
heritable
refers to any characteristics or traits that are influenced by heredity
heterozygous
having two different alleles for a trait
homozygous
having two of the same allele for a trait
lobes
major areas of the cortex associated with general categories of behavior
multifactorial
refers to traits that are affected by a host of environmental factors as well as genetic ones
mutation
a change in a section of DNA
myelin sheath
a fatty sheath that forms around certain axons in the body and increases the speed and efficiency of information transmission
myelination
the formation of myelin (a fatty sheath) around the axons of neurons that speeds and increases information-processing abilities
neurogenesis
the proliferation of neurons through cell division
neurons
cells that are specialized for sending and receiving messages between the brain and all parts of the body, as well as within the brain itself
norm of reaction
all the phenotypes that can theoretically result from a given genotype in relation to all the environments in which it can survive and develop
occipital lobe
the lobe of the cortex that is primarily involved in processing visual information
parietal lobe
governs spatial processing as well as integrating sensory input with information stored in memory
phenotype
the observable expression of the genotype, including both body characteristics and behavior
phenylketonuria (PKU)
a disorder related to a defective recessive gene on chromosome 12 that prevents metabolism of phenylalanine
plasticity
the capacity of the brain to be affected by experience
polygenic inheritance
inheritance in which traits are governed by more than one gene
recessive allele
the allele that is not expressed if a dominant allele is present
regulator genes
genes that control the activity of other genes
secular trends
marked changes in physical development that have occurred over generations
sex chromosomes
the chromosomes (X and Y) that determine an individual’s gender
spines
formations on the dendrites of neurons that increase the dendrites’ capacity to form connections with other neurons
synapses
microscopic junctions between the axon terminal of one neuron and the dendritic branches or cell body of another
synaptic pruning
the normal developmental process through which synapses that are rarely activated are eliminated
synaptogenesis
the process by which neurons form synapses with other neurons, resulting in trillions of connections
temporal lobe
the lobe of the cortex that is associated with memory, visual recognition, and the process of emotion and auditory information
