Unit 1: Biological Bases of Behavior Practice Flashcards

Comprehensive vocabulary flashcards covering the biological mechanisms of behavior, including genetics, the nervous system, pharmacology, the brain, sleep, and sensory systems as outlined in the Unit 1 guide.

Natural Selection

The principle that inherited traits that better enable an organism to survive and reproduce in a particular environment will most likely be passed on to succeeding generations.

Monozygotic Twins

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

Dizygotic Twins

Fraternal twins who develop from separate fertilized eggs; they are genetically no closer than ordinary brothers and sisters.

Epigenetics

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

Sympathetic Nervous System

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

Parasympathetic Nervous System

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

Myelin

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.

Action Potential

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

All-or-Nothing Principle

A neuron's reaction of either firing (with a full-strength response) or not firing.

Reuptake

A neurotransmitter's reabsorption by the sending neuron.

Agonist

A molecule that increases a neurotransmitter's action by mimicking it or blocking its reuptake.

Antagonist

A molecule that inhibits or blocks a neurotransmitter's action.

Endocrine System

The body's 'slow' chemical communication system; a set of glands that secrete hormones into the bloodstream.

Brain Plasticity (neuroplasticity)

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

fMRI

A technique for revealing bloodflow and, therefore, brain activity by comparing successive MRI scans.

Medulla Oblongata

The base of the brainstem; controls heartbeat and breathing.

Limbic System

Neural system located below the cerebral hemispheres; associated with emotions and drives.

Corpus Callosum

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

Broca’s Area

A brain area, usually in the left frontal lobe, that helps control language expression and directs muscle movements involved in speech.

Wernicke’s Area

A brain area, usually in the left temporal lobe, involved in language comprehension and expression.

Circadian Rhythm

The biological clock; regular bodily rhythms (for example, of temperature and wakefulness) that occur on a 24-hour cycle.

Suprachiasmatic Nucleus (SCN)

A pair of cell clusters in the hypothalamus that controls circadian rhythm by causing the pineal gland to adjust melatonin production.

Activation Synthesis Theory

The dream theory suggesting that dreams are the brain's attempt to synthesize random neural activity.

Signal Detection Theory

A theory predicting how and when we detect the presence of a faint stimulus (signal) amid background stimulation (noise).

Weber’s Law

The principle that, to be perceived as different, two stimuli must differ by a constant minimum percentage (rather than a constant amount).

Transduction

Conversion of one form of energy into another. In sensation, the transforming of stimulus energies into neural impulses our brain can interpret.

(Young-Helmholtz) Trichromatic Theory

The theory that the retina contains three different types of color receptors (cones)—one most sensitive to red, one to green, one to blue.

Opponent-Process Theory

The theory that opposing retinal processes (red-green, blue-yellow, white-black) enable color vision.

Cochlea

A coiled, bony, fluid-filled tube in the inner ear; sound waves traveling through the cochlear fluid trigger nerve impulses.

Place Theory

In hearing, the theory that links the pitch we hear with the place where the cochlea's membrane is stimulated.

Gate Control Theory

The theory that the spinal cord contains a neurological 'gate' that blocks pain signals or allows them to pass on to the brain.

Vestibular Sense

The sense of body movement and position, including the sense of balance.