Biological Bases of Behavior Vocab

1.     Behavior Genetics

The relative power and limits of genetic and environmental influences on behavior

2.     Environment

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

3.     Genes

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

4.     Identical Twins

Twins who develop from a single egg that splits into two, creating two genetically identical organisms

5.     Fraternal Twins

Twins who develop from separate fertilized eggs, genetically like siblings but share a fetal environment

6.  Heritability

The proportion of variation among individuals that we can attribute to genes; may vary on the range of populations and environments

7.  Interaction

Interplay that occurs when the effect of one factor (environment) depends on another factor (heredity)

8.  Epigenetics

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

9.  Natural Selection

Principle that traits that contribute to reproduction and survival will be passed on.

10.  Mutation

A random error in gene replication that leads to a change

11. Blood-brain barrier

Acts as a filter for the brain, keeping out harmful substances

12. Psychoactive drugs

A chemical substance that alters perceptions and moods

13. tolerance

Diminishing effect with regular use of the same dose of a drug, requiring the user to take larger doses before having the drug’s effect

14. addiction

Compulsive craving of drugs or certain behaviors despite known adverse consequences

15. withdrawal

Discomfort and distress that follow discontinuing an addictive drug or behavior

16. depressants

Drugs (like alcohol, barbiturates, and opiates) that reduce neural activity and slow body functions

17. stimulants

Drugs (like caffeine, nicotine, cocaine, ecstasy, etc) that excite neural activity and speed up body functions

18. hallucinogens

Psychedelic drugs, such as LSD, that distort perceptions and evoke sensory images in the absence of sensory input

19. Resting potential

Positive outside/ a resting axon negative inside state

20. Action potential

Neural impulse, a brief electrical charge that travels down an axon

21. All-or-nothing response

Neuron’s reaction of either firing (with a full strength response) or not firing

22. Refractory period

A period of inactivity after a neuron has fired

23. threshold

A level of stimulation required to trigger a neural impulse

24. dopamine

Influences movement, learning, attention, and emotion

25. serotonin

Affects mood, hunger, sleep, and arousal

26. norepinephrine

Helps control alertness and arousal

27. glutamate

Major excitatory neurotransmitter; involved in memory

28. GABA

Major inhibitory neurotransmitter

29. endorphins

“Morphine within”- natural, opiate- like neurotransmitters linked to pain control and pleasure

30. Substance p

a compound involved in the synaptic transmission of pain and other nerve impulses.

31. acetylcholine

Enables muscles action, learning, and memory (ACh)