Biopsychology Exam 1 Terms

biopsychology

the scientific study of the biology of behavior

nature

we are a product of what we inherited

nurture

we are a product of our environment and experiences

monozygotic twins (identical twins)

develop from the same egg and sperm (zygote) and therefore are genetically identical

dizygotic twins (fraternal twins)

who develop from two separate zygotes (sperm/egg)

heritable estimate

the proportion of variability as a result of the genetic variability in a given study

evolution 

a gradual orderly change in the structure and physiology of plants and animals from preexisting species generally producing more complex organisms

homologous

structures that are similar because they have a common evolutionary origin

analogous

structures that are similar but do not have a common evolutionary origin

convergent evolution

evolution in unrelated species of similar solutions to the same environmental demands

survival of the fittest

those species and biological characteristics that are better adapted to the environment are more likely to survive and pass on their genes (fitness)

lamarckian evolution

the use or disuse of a structure (e.g., little toes) effect the evolution of the feature

evolutionary psychology

focuses upon functional and evolutionary explanations of how behaviors evolved

genes

discrete unites of heredity

dichotomous traits

occur in one form or another

true breeding

offspring always have the same trait

dominant trait

occurs most often

recessive trait

occurs less frequent

alleles

two genes that control the same trait

homozygous

two of the same alleles

heterozygous

two different alleles for a trait

dominant allele

will produce its effect regardless of which allele it is paired with (upper case)

recessive allele

will only be expressed when it is paired with the same allele (lower case)

sex linked traits

traits that are influenced by genes on the sex chromosomes

gametes

sperm cells and egg cells

meiosis 

cell division of 1 cell, where it divides to 2 cells

zygote

fertilized cell

chromosome

2 deoxyribonucleic acid (DNA) strands

DNA strand

sequence of nucleotide bases

nucleotide bases

• adenine

• thymine

• guanine

• cytosine

mutation

a heritable change to DNA

proteins

long chains of amino acids

histones

clusters of proteins

RNA

ribonucleic acid, like DNA but has uracil instead of thymine

translation

the RNA attaches to the ribosome

enhancers

initiate the synthesis of proteins, and determines rate of synthesis

epigenetics

the study of mechanisms that influence gene expression without changing the genes themselves

methyl tags

keeps it tight, silencing the gene

acetyl tags

loosens the DNA activating the gene

neurons

transmit electrical signal, information processing

glia

non-electrical, supporting cells

cytoplasm

jellylike substance that fills the cell body/soma

ions

charged atoms 

blood brain barrier

a mechanism that surrounds the brain and blocks most chemicals from entering

action potential

results from a sudden change in the electrical properties of the neuron membrane in an axon

intracellular fluid

fluid within cells

extracellular fluid

fluid surrounding and between cells

electrical potential

the difference in voltage between the intra- and extracellular fluid

hyperpolarization

making the membrane potential more negative

depolarization

make the membrane potential more positive

absolute refractory period

the first part of the period in which the membrane cannot produce and action potential

relative refractory period

the second part, in which it takes a stronger than usual stimulus to trigger an action potential

propagation

traveling down the axon

temporal summation

repeated stimuli can have a cumulative effect and can produce a nerve impulse when a single stimuli is too weak

spatial summation

synaptic input from several locations can have a cumulative effect and trigger a nerve impulse

vesicles

tiny spherical packets located in the presynaptic terminal where neurotransmitters are held for release

exocytosis

bursts of release of neurotransmitter from the presynaptic terminal into the synaptic cleft

metabotropic

neurotransmitters attach to a receptor and initiate a sequence of slower and longer lasting metabolic reactions

autoreceptors

receptors that detect the amount of transmitter released and inhibit further synthesis and release

postsynaptic neurons

respond to stimulation by releasing chemicals that travel back to the presynaptic terminal where they inhibit further release

agonist

drugs that facilitate (e.g., by mimicking) a neurotransmitter

antagonist

drugs that inhibit the effects of a neurotransmitter (e.g., blocking the receptor)

tolerance

decrease in effect as an addiction develops

withdrawal

body’s reaction to absence of the drug