VOCAB

Question 1

The Study of the relative power and limits of genetics and environmental influences and behavior

Answer 1

Behavioral Genetics

Question 2

every external influence, from prenatal nutrition to the people and things around us.

Answer 2

Environment

Question 3

threadlike structures made of DNA molecules that contain the genes

Answer 3

Chromosomes

Question 4

a complex molecule containing the
genetic information that makes up
the chromosomes.

Answer 4

DNA (deoxyribonucleic acid)

Question 5

the biochemical units
of heredity that make up the
chromosomes; segments of DNA
capable of synthesizing proteins.

Answer 5

Genes

Question 6

the complete instructions
for making an organism, consisting
of all the genetic material in that
organism’s chromosomes.

Answer 6

Genome

Question 6

twins who develop from
a single fertilized egg that splits
in two, creating two genetically
identical organisms

Answer 6

Identical twins (Monozygotic twins)

Question 7

twins who develop from separate
fertilized eggs. They are genetically
no closer than brothers and sisters,
but they share a fetal environment.

Answer 7

Fraternal twins (dizygotic twins)

Question 8

the subfield of biology that studies the
molecular structure and function
of genes.

Answer 8

Molecular genetics

Question 9

the proportion of variation among individuals that we can attribute to genes. The heritability of a trait may vary, depending on the range of populations and
environments studied.

Answer 9

Heritability

Question 10

the interplay that occurs when the effect of one factor (such as environment) depends on another factor (such as heredity).

Answer 10

Interaction

Question 11

the study of environmental influences on gene expression that occur without a
DNA change

Answer 11

Epigenetics

Question 12

the study of the evolution of behavior
and the mind, using principles of
natural selection.

Answer 12

Evolutionary psychology

Question 12

the principle that, among the range of inherited trait variations, those contributing
to reproduction and survival
will most likely be passed on to
succeeding generations.

Answer 12

Natural Selection

Question 13

A random error in gene replication that leads to a change

Answer 13

Mutation

Question 14

the scientific study of the links
between biological (genetic, neural,
hormonal) and psychological
processes. (Some biological
psychologists call themselves
behavioral neuroscientists,
neuropsychologists, behavior
geneticists, physiological psychologists,
or biopsychologists.)

Answer 14

Biological Psychology

Question 15

a nerve cell; the basic
building block of the nervous
system.

Answer 15

Neuron

Question 16

a neuron’s bushy,
branching extensions that receive
messages and conduct impulses
toward the cell body.

Answer 16

Dendrites

Question 17

the neuron extension that
passes messages through its
branches to other neurons or to
muscles or glands.

Answer 17

Axon

Question 18

a fatty tissue layer segmentally encasing
the axons of some neurons; enables
vastly greater transmission speed
as neural impulses hop from one
sausage-like node to the next

Answer 18

Myelin sheath

Question 19

a neural impulse;
a brief electrical charge that travels
down an axon.

Answer 19

Action potential

Question 19

a period of inactivity after a neuron has fired

Answer 19

Refractory period

Question 19

the level of stimulation
required to trigger a neural impulse.

Answer 19

Threshold

Question 19

a neuron’s reaction of either firing (with a fullstrength response) or not firing

Answer 19

All-or-none response

Question 19

the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron. The tiny gap at this junction is called the synaptic gap or synaptic cleft.

Answer 19

Synapse

Question 19

chemical messengers that cross the synaptic gaps between neurons. When released by the sending neuron, neurotransmitters travel across the synapse and bind to receptor sites on the receiving neuron, thereby influencing whether that neuron will generate a neural impulse

Answer 19

Neurotransmitters

Question 19

a neurotransmitter’s reabsorption by the sending neuron.

Answer 19

Reuptake

Question 20

“morphine within”—natural, opiate-like neurotransmitters linked to pain control and to pleasure.

Answer 20

Endorphins

Question 21

a molecule that, by binding to a receptor site, stimulates a response.

Answer 21

Agonist

Question 22

a molecule that, by binding to a receptor site, inhibits or blocks a response.

Answer 22

Antagonist

Question 22

neurons within the brain and spinal cord that communicate internally and intervene between the sensory inputs and motor outputs.

Answer 22

Interneurons

Question 22

bundled axons that form neural “cables” connecting the central nervous system with muscles, glands, and sense organs

Answer 22

nerves

Question 23

the division of the autonomic nervous system that calms the body, conserving its energy.

Answer 23

Parasympathetic nervous system

Question 23

the body’s speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems.

Answer 23

Nervous system

Question 23

neurons that carry incoming information from the sensory receptors to the brain and spinal cord

Answer 23

Sensory (afferent) neurons

Question 23

the sensory and motor neurons that connect the central nervous system (CNS) to the rest of the body.

Answer 23

Peripheral nervous system (PNS)

Question 23

the division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations.

Answer 23

Sympathetic nervous system

Question 23

the part of the peripheral nervous system that controls the glands and the muscles of the internal organs (such as the heart). Its sympathetic division arouses; its parasympathetic division calms.

Answer 23

Autonomic nervous system (ANS)

Question 23

neurons that carry outgoing information from the brain and spinal cord to the muscles and glands.

Answer 23

Motor (efferent) neurons

Question 23

The brain and the spinal cord

Answer 23

central nervous system (CNS)

Question 23

a simple, automatic response to a sensory stimulus, such as the knee-jerk response.

Answer 23

Reflex

Question 23

the body’s “slow” chemical communication system; a set of glands that secrete hormones into the bloodstream.

Answer 23

Endocrine system

Question 23

the division of the peripheral nervous system that controls the body’s skeletal muscles. Also called the skeletal nervous system

Answer 23

Somatic nervous system

Question 23

a pair of endocrine glands that sit just above the kidneys and secrete hormones (epinephrine and norepinephrine) that help arouse the body in times of stress.

Answer 23

Adrenal glands

Question 23

chemical messengers that are manufactured by the endocrine glands travel through the bloodstream and affect other tissues.

Answer 23

Hormones

Question 24

tissue destruction. A brain lesion is a naturally or experimentally caused destruction of brain tissue.

Answer 24

Lesion

Question 24

the endocrine system’s most influential gland. Under the influence of the hypothalamus, the pituitary regulates growth and controls other endocrine glands.

Answer 24

Pituitary glands

Question 24

a series of X-ray photographs taken from different angles and combined by computer into a composite representation of a slice of the brain’s structure. (Also called CAT scan.)

Answer 24

CT (computed tomography) scan (CAT scan)

Question 24

an amplified recording of the waves of electrical activity sweeping across the brain’s surface. These waves are measured by electrodes placed on the scalp.

Answer 24

(EEG) Electroencephalogram

Question 24

a visual display of brain activity that detects where a radioactive form of glucose goes while the brain performs a given task.

Answer 24

PET (positron emission tomography) scan

Question 25

the oldest part and central core of the brain, beginning where the spinal cord swells as it enters the skull; the brainstem is responsible for automatic survival functions

Answer 25

Brainstem

Question 25

a technique that uses magnetic fields and radio waves to produce computer-generated images of soft tissue. MRI scans show brain anatomy.

Answer 25

MRI (magnetic resonance imaging)

Question 25

a technique for revealing blood flow and, therefore, brain activity by comparing successive MRI scans. fMRI scans show brain function as well as its structure.

Answer 25

fMRI (functional MRI)

Question 25

the “little brain” at the rear of the brainstem; functions include processing sensory input, coordinating movement output and balance, and enabling nonverbal learning and memory.

Answer 25

Cerebellum

Question 25

the base of the brainstem; controls heartbeat and breathing.

Answer 25

Medulla

Question 25

a nerve network that travels through the brainstem and thalamus and plays an important role in controlling arousal.

Answer 25

Reticular formation

Question 26

the brain’s sensory control center, located on top of the brainstem; it directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla.

Answer 26

Thalamus

Question 27

two lima-bean-sized neural clusters in the limbic system; linked to emotion.

Answer 27

Amygdala

Question 27

neural system (including the hippocampus, amygdala, and hypothalamus) located below the cerebral hemispheres; associated with emotions and drives.

Answer 27

Limbic system

Question 27

a neural structure lying below (hypo) the thalamus; it directs several maintenance activities (eating, drinking, body temperature), helps govern the endocrine system via the pituitary gland, and is linked to emotion and reward.

Answer 27

Hypothalamus

Question 28

the intricate fabric of interconnected neural cells covering the cerebral hemispheres; the body’s ultimate control and information-processing center.

Answer 28

Cerebral cortex

Question 29

portion of the cerebral cortex lying just behind the forehead; involved in speaking and muscle movements and in making plans and judgments.

Answer 29

Frontal Lobes

Question 29

cells in the nervous system that support, nourish, and protect neurons; they may also play a role in learning and thinking.

Answer 29

Glial cells

Question 29

portion of the cerebral cortex lying at the top of the head and toward the rear; receives sensory input for touch and body position.

Answer 29

Parietal Lobes

Question 29

portion of the cerebral cortex lying at the back of the head; includes areas that receive information from the visual fields

Answer 29

Occipital Lobes

Question 30

portion of the cerebral cortex lying roughly above the ears; includes the auditory areas, each receiving information primarily from the opposite ear.

Answer 30

temporal lobes

Question 31

an area at the rear of the frontal lobes that controls voluntary movements.

Answer 31

Motor cortex

Question 32

area at the front of the parietal lobes that registers and processes body touch and movement sensations.

Answer 32

Somatosensory cortex

Question 33

the brain’s ability to change, especially during childhood, by reorganizing after damage or by building new pathways based on experience.

Answer 33

Plasticity

Question 33

a condition resulting from surgery that isolates the brain’s two hemispheres by cutting the fibers (mainly those of the corpus callosum) connecting them.

Answer 33

Split Brain

Question 33

areas of the cerebral cortex that are not involved in primary motor or sensory functions; rather, they are involved in higher mental functions such as learning, remembering, thinking, and speaking.

Answer 33

Association areas

Question 33

the large band of neural fibers connecting the two brain hemispheres and carrying messages between them.

Answer 33

Corpus callosum

Question 34

the formation of new neurons.

Answer 34

neurogenesis