Biology 1

Across
3.	_____Reduced response to a drug after repeated use. Tolerance
6.	_____P Neurotransmitter involved in pain perception. Substance
7.	_____studies Research comparing similarities between identical and fraternal twins. Twin
8.	_____period Time after an action potential when a neuron can’t fire again. Refractory
9.	_____studies Research examining traits among family members. Family
12.	Major excitatory neurotransmitter involved in learning and memory. Glutamate
16.	_____Compulsive drug use despite harmful consequences. Addiction
17.	_____nervous system Controls voluntary movements. Somatic
18.	_____perspective How natural selection influences behavior and mental processes. Evolutionary
20.	_____Symptoms experienced when stopping or reducing drug use. Withdrawal
25.	_____neurotransmitters Chemicals that stimulate neurons to fire. Excitatory
27.	Controls involuntary bodily functions AKA The Autonomic nervous system. ANS
28.	Genetic and biological factors influencing development. Nature
30.	_____selection Process where traits that enhance survival are passed on. Natural
33.	_____Drugs that relieve pain and produce euphoria. Opioids
35.	_____arc Pathway for reflex actions. Reflex
36.	_____nervous system Promotes rest and digestion. Parasympathetic
37.	_____potential Electrical impulse traveling down a neuron. Action
41.	_____ inhibitors Drugs that block the reabsorption of neurotransmitters. Reuptake
43.	Neurotransmitter involved in muscle action, learning, and memory. Acetylcholine
44.	Environmental factors influencing development. Nurture
45.	_____Stimulant that increases dopamine levels. Cocaine
47.	_____predisposition Increased likelihood of developing a condition based on genetics. Genetic
48.	_____Drug that can act as a depressant, stimulant, or hallucinogen. Marijuana
51.	_____neurons Transmit sensory information to the CNS. Sensory
52.	Hormone that regulates hunger and energy balance. Leptin
55.	_____Stimulant that increases alertness. Caffeine
56.	Hormone involved in social bonding and childbirth. Oxytocin
57.	Hormone that regulates sleep-wake cycles. Melatonin
58.	Hormone that stimulates appetite. Ghrelin
59.	Controversial practice of improving genetic quality by selective breeding. Eugenics
61.	_____neurons Transmit commands from the CNS to muscles. Motor

Down
1.	Brain and spinal cord. AKA The Central nervous system CNS
2.	Reduction in membrane potential making a neuron more likely to fire. Depolarization
4.	Drugs that block or reduce neurotransmitter effects. Antagonists
5.	____neurotransmitters Chemicals that prevent neurons from firing. Inhibitory
10.	_____Drugs that increase neural activity and energy. Stimulants
11.	_____Drugs that decrease neural activity and slow body functions. Depressants
13.	_____or-nothing principle Neuron either fires completely or not at all. All
14.	_____Opioid that is highly addictive. Heroin
15.	Nerves outside the CNS. AKA The Peripheral nervous system PNS
19.	Hormone that prepares the body for fight-or-flight response. Adrenaline
21.	Connect neurons within the CNS. Interneurons
22.	_____transmission Process of sending signals between neurons. Neural
23.	_____gravis Autoimmune disorder causing muscle weakness. Myasthenia
24.	_____sclerosis Disease where the immune system attacks the myelin sheath of neurons. Multiple
26.	_____Drugs that cause perceptual distortions. Hallucinogens
29.	Minimum stimulus needed to trigger an action potential. Threshold
30.	Neurotransmitter involved in arousal and alertness. Norepinephrine
31.	_____studies Research comparing adopted children to their biological and adoptive parents. Adoption
32.	_____nervous system Activates fight-or-flight response. Sympathetic
34.	Neurotransmitter involved in reward, motivation, and motor control. Dopamine
38.	_____potential Electrical charge across the neuron membrane when not firing. Resting
39.	Transmission of traits from parents to offspring. Heredity
40.	_____cells Support and protect neurons. Glial
42.	Drugs that mimic or enhance neurotransmitter effects. Agonists
46.	Reabsorption of neurotransmitters by the sending neuron. Reuptake
47.	Major inhibitory neurotransmitter that reduces neuronal excitability. GABA
49.	Neurotransmitter affecting mood, sleep, and appetite. Serotonin
50.	Chemical messengers released by glands to regulate bodily functions. Hormones
53.	_____Depressant that affects motor skills and judgment. Alcohol
54.	Neurotransmitters that act as natural painkillers and mood enhancers. Endorphins
60.	_____Nerve cells transmitting information. Neurons