Deck 18: Genetics of Behavior

Question 1

As the average age of the population increases,the incidence of Alzheimer's disease is also expected to increase.

Answer 1

True

Question 2

Huntington disease is _____.

A) a model of a multifactorial trait, controlled by several genes
B) inherited as an X-linked dominant trait
C) a disease with onset in early childhood
D) one that produces no significant changes in brain cells
E) a model of a single gene defect affecting behavior

Answer 2

E

Question 3

The greater the polyglutamine expansion in the huntingtin gene (greater than 35 CAG trinucleotide repeats),the greater the chance for developing Huntington disease.

Answer 3

True

Question 4

The finding that mutations in synapse genes are associated with many genetic disorders that have a behavioral component suggests that _____.

A) individuals with these mutations lack synapses
B) individuals with these mutations lack neurotransmitters
C) malfunctions in presynaptic neurons cause abnormal behavior
D) malfunctioning synapses are associated with abnormal behavior
E) behavior disorders are attributable to environmental factors

Question 5

Females who are heterozygous for a violence-associated mutation in the X-linked MAOA gene will display abnormal behavior.

Question 6

Research on transgenic Drosophila models of Huntington disease has found that ____.

A) the NUB1 protein decreases levels of mutant huntingtin protein, and thereby, cell death
B) the mutant huntingtin protein is destroyed by the SOD1 protein
C) Drosophila and humans share more than 90% of genes
D) the accumulation of mutant proteins in the brain causes Huntington disease
E) treatment of patients with Rhes protein cures Huntington disease

Question 7

If a psychiatric condition displays 15% concordance in monozygotic twins,and 8% concordance in dizygotic twins,then genetics plays a major role in this trait.

Question 8

A mutation in the MAOA gene is associated with ____ behavior.

A) depressive
B) risk-taking
C) violent
D) schizophrenic
E) bipolar

Question 9

When a nerve impulse travels from neuron 1 to neuron 2,neuron 1 is known as the _____.

A) postsynaptic neuron
B) presynaptic neuron
C) synapse
D) gated channel
E) dendrite

Question 10

The transgenic mouse models for amyotrophic lateral sclerosis (ALS)and Huntington disease show symptoms similar to those seen in humans affected by these conditions.

Question 11

Drugs,such as cocaine and nicotine,mimic the action of neurotransmitters.

Question 12

What is the function of a normal MAOA protein?

A) It breaks down neurotransmitters in the synapse.
B) It carries neurotransmitters across synapses.
C) It is a neurotransmitter.
D) It is an enzyme essential in the formation of certain neurotransmitters.
E) It is an enzyme responsible for the construction of neurotransmitter receptors.

Question 13

All psychiatric illnesses studied to date have been shown to result from a mutation in a single gene.

Question 14

It is difficult to assign a precise phenotypic definition to alcoholism because _____.

A) not enough volunteers agree to participate in genome wide association studies
B) alcoholism does not have environmental components
C) alcoholism is an innate behavior
D) genetic testing for alcoholism is not available
E) excessive consumption of alcohol is subjective 

Question 15

Why is the most damage to the brains of Huntington disease patients observed in the striatum?

A) The Rhes protein, needed for mutant huntingtin to become toxic, is only produced in the striatum.
B) The huntingtin gene is only expressed in the striatum.
C) The mutant huntingtin protein becomes toxic when bound to the Rhes protein, which is abundant in the striatum.
D) Only the cells of the striatum contain the huntingtin mutation.
E) The CAG expansions are corrected in regions of the brain other than the striatum.

Question 16

To quantify the environmental contribution of a behavioral trait,scientists turn to ____.

A) whole genome sequencing
B) heritability
C) genome wide association studies
D) analysis of innate behaviors
E) SNP and haplotype analyses

Question 17

Researchers have found that schizophrenia may be caused by multiple genes,each contributing equally to the behavioral phenotype. This is an example of _____.

A) a polygenic additive model
B) epistasis
C) single gene, dominant trait
D) single gene, recessive trait
E) genome wide association

Question 18

Learned behaviors are defined as behaviors with which we are born.

Question 19

Because sons adopted by alcoholic men show a rate of alcoholism more like that of their biological father,there is an argument for the role of genetic factors in this disease.

Question 20

Individuals with a genetic variant in the promoter region of the MAOA gene display violent behavior,independent of environmental factors.

Question 21

Research using transgenic animal models of neurodegenerative diseases not only helps scientists understand the disorders,but also may lead to _____.

A) new vaccines
B) Drosophila genome sequencing projects
C) discovery of the environmental causes of schizophrenia
D) identification of the mutant gene that causes Huntington disease
E) new drugs and treatments

Question 22

It is clear from current research on human behavior genetics that _____.

A) animal models of human disease are not useful for behavior research
B) epigenetics does not play a significant role in behavior disorders
C) few abnormal behaviors have an environmental component
D) most abnormal behaviors are due to single-gene effects
E) abnormal behaviors are not due to single-gene effects

Question 23

The problem with defining abnormal behavior is that ____.

A) too many disorders have similar phenotypes
B) some behaviors are not abnormal, but simply variants
C) biological factors related to abnormal behavior are not known
D) mental illness is multifactorial, and therefore, cannot be defined
E) twin concordance studies mental illness is due mostly to environmental components

Question 24

The observation that schizophrenia is associated with duplications of a certain copy number variant (CNV),while autism spectrum disorders are associated with deletions of the same CNV,suggests that _____.

A) CNV mutations are present in all psychiatric disorders
B) both disorders have identical phenotypes
C) both disorders have an environmental component
D) both disorders share common developmental pathways 
E) neither disorder has a genetic component

Question 25

Since mice are over _____________________% genetically similar to humans,they are appropriate models for studying human conditions.

Question 26

For which of the following diseases would animal models likely yield the most information?

A) alcoholism
B) schizophrenia
C) bipolar disorder
D) Huntington disease
E) nicotine addition

Question 27

Monozygotic twin concordance values are less than 100% in both bipolar disorder and schizophrenia.This suggests that these disorders ____.

A) are strictly polygenic
B) have environmental components
C) are X-linked
D) genetically dominant 
E) are not genetically based

Question 28

The gene associated with aggressive behavior in different studies is called _____________________.

Question 29

Transgenic mice engineered to contain the mutant versions of the huntingtin gene with various numbers of _____________________ repeats have phenotypes similar to humans affected by Huntington disease.

Question 30

The mutant huntingtin protein is _____________________,meaning that it kills cells,such as those in the brain and nervous system.

Question 31

Someone who steps on a sharp nail will quickly lift their foot away. This quick reaction is known as a(n)_____________________.

Question 32

According to results from genome wide association studies,at least seven _____________________ are linked to both schizophrenia and bipolar disorder.

Question 33

The normal _____________________ protein binds to hundreds of other proteins to facilitate synaptic function,cell signaling,intracellular transport,and transcription.

Question 34

_____________________ is defined as the interaction of two or more gene variants to produce a certain phenotype.

Question 35

Individuals with nicotine acetylcholine receptors that bind tightly to nicotine are more likely to _____.

A) have a family member who is resistant to nicotine addiction
B) have behavioral disorders
C) have mutations in the GABBR2 gene
D) be vulnerable to nicotine addiction
E) show resistance to nicotine addiction

Question 36

The axon of one neuron is functionally connected to the dendrite of an adjacent neuron by the _____________________.

Question 37

The only gene that has been positively identified with the onset of Alzheimer disease encodes a protein that _____.

A) is involved in cholesterol metabolism
B) breaks down neurotransmitters
C) maintains the health of striatum cells
D) attaches amino acids to tRNA molecules
E) breaks down fatty deposits around neurons

Question 38

Transgenic mice carrying a mutant human SOD1 gene are used as models to study _____________________.

Question 39

An ALDH2 allele results in slow alcohol metabolism,leading to an accumulation of acetaldehyde.Therefore,individuals with this allele tend to _____.

A) consume more alcohol than typical social drinkers
B) be protected against alcoholism
C) become alcoholics at high rates
D) contain other alleles that protect against alcoholism
E) have parents who are alcoholics

Question 40

Schizophrenia and bipolar disorder are caused by _____.

A) one gene, plus environmental triggers
B) the same gene
C) many genes, plus environmental triggers
D) copy number variants, without environmental triggers
E) the same mutations that cause autism spectrum disorders

Question 41

Would you recommend genetic testing for the APOE*4 allele in family members of an Alzheimer disease patient?  Why or why not?

Question 42

Do you think that nonsubstance-related addictions,such as compulsive gambling or compulsive eating,have a greater genetic or environmental component compared to substance-related additions,such as nicotine?  Explain your reasoning.

Question 43

Figure 18.3(a)

Identify the numbered items in the accompanying figure.Include the following terms in your description.
presynaptic neuron
postsynaptic neuron
neurotransmitters waiting to be released
neurotransmitters released by the nerve impulse
synapse
receptors with bound neurotransmitters

Question 44

_____________________develops from physiological adaptations that change brain function when exposed to certain environmental triggers.

Question 45

The _____________________ movement overemphasized the role of genetics in human behavior,leading to the forced sterilization of those who were considered genetically inferior based on personality traits.

Question 46

Discuss the importance of twin and adoption studies to human behavioral genetics research.

Question 47

Explain why mice are appropriate animal models for human behavioral genetics research.

Question 48

To summarize the conclusions of modern human behavioral genetics research,behavior is influenced by _____________________,_____________________,and _____________________ factors.

Question 49

Suppose Stephen Mobley,who was convicted and executed for the murder of John Collins,carried the variant of the MAOA gene that has been associated with violent behavior. If you were on the jury that convicted and sentenced Mobley,would this information have influenced your view of his guilt or innocence?  Would it have changed your opinion of his sentence?  Why or why not?

Question 50

Individuals homozygous for the APOE*4 Apolipoprotein E allele are ten to fifteen times more likely to develop _____________________.

Question 51

The neurotransmitter _____________________ functions in the areas of the brain associated with mood,attention,arousal and memory,and is associated with nicotine addiction.

Question 52

Explain how genetic mutations that cause neurodegenerative disorders such as Huntington disease and Alzheimer disease can also cause abnormal behavior.

Question 53

Family,twin,and adoption studies have revealed a(n)_____________________ component to mental illnesses,such as bipolar disorder.

Question 54

A study revealed differences in DNA methylation patterns between monozygotic twins,only one of whom was affected by a schizophrenia or bipolar disorder. This suggests a role for ____ in mental illness.

Question 55

Discuss the tools used to see if human behavior has a genetic component,and give two examples of either normal or abnormal behavior that appears to have a genetic component.

Question 56

Amyloid plaques are routinely found in the brains of individuals affected by _____________________,where they cause nerve cell degeneration and death.

Question 57

Discuss the dangers of placing too much emphasis on the genetic basis of personality and behavior.

Question 58

Discuss the difficulties in studying the genetics of human behavior traits

Question 59

_____________________ can be defined as compulsive and repetitive behavior which can lead to impairment.

Question 60

Alzheimer disease has two forms: the early onset _____________________ form with a strong pattern of familial inheritance,and the late onset _____________________ form.