Final Exam Flashcards

What type of environments can trigger gene expression linked to Antisocial Personality Disorder (ASPD)?

Chronic stress and childhood maltreatment.

What can detect Alzheimer’s-related changes years before symptoms appear?

Blood biomarkers.

Low maternal care increases DNA methylation and worsens what two outcomes?

Learning and memory.

What environmental stressor may activate genetic vulnerability for schizophrenia?

Adolescent cannabis use.

Genetic variation influences whether someone is a “morning person” or a “night person.” What is this trait called?

Chronotype.

What finding about OCD suggests different biological pathways for symptom types?

Different OCD symptoms (hoarding vs. checking) have different genetic causes.

What do epigenetic studies reveal about newborns who later develop Autism Spectrum Disorder?

They show distinct DNA methylation patterns before symptoms appear.

Postnatal environmental stressors increase levels of what molecule associated with repetitive ASD behaviors?

HDAC (related to histone modification and gene expression).

Which inbred rat strain is considered the best animal model for ADHD?

SHR (Spontaneously Hypertensive Rat).

Genes affecting what receptor type change how nicotine acts on the dopamine system?

Nicotinic acetylcholine receptors.

Research on anxiety disorders has found gene-expression associations in what genomic locations?

Both coding and noncoding regions on separate chromosomes.

Genetic alcohol research typically focuses on genes involved in metabolism and what other system?

The dopaminergic reward system.

What distinguishes genetic influences on childhood gender nonconformity (CGN) in boys from those on male sexual orientation?

They appear to involve different genetic factors.

Which sex shows higher heritability for PTSD and is twice as likely to develop it?

Females.

Traumas that produce epigenetic changes likely to pass to offspring tend to include which example?

A robbery.

Genes related to dyslexia have been shown to influence which emotional trait in animal models?

Anxiety.

What two animals are most commonly used in insomnia research?

Zebrafish and fruit flies.

Researchers found increased shared genes between insomnia and multiple sclerosis in participants above what age?

Age 40.

ADHD shows higher heritability during childhood compared to adulthood because of what phenomenon?

Symptoms change over time.

What is the genetic relationship between Bipolar I and Bipolar II?

Their genotypes appear to be different.

People with more dopamine receptor repeats tend to engage in what type of behavior?

Riskier sexual behavior.

What is the primary historical debate in Behavioral Genetics?

Nature vs. nurture.

Continuous variation caused by many genes is known as what type of genetics?

Polygenic genetics.

What term describes having two different alleles for a trait?

Heterozygous.

The Nazis’ eugenics policies were based on policies originally written where?

The United States.

When two different alleles produce an intermediate phenotype, what is this called?

Incomplete dominance.

What is the phenomenon in which triplet repeats increase across generations, causing earlier and more severe symptoms?

Genetic anticipation.

True or False: Individual genes for continuous traits follow Mendel’s laws of heredity.

True.

What does “MZ” stand for in twin studies?

Monozygotic.

What term describes a trait influenced by many genes?

Polygenic.

DZ twins are just as genetically similar as what type of relatives?

Non-twin siblings.

In the ACE model, what do A, C, and E represent?

Additive genetics, shared environment, and nonshared environment.

The maze-bright vs. maze-dull rat study showing effects of enriched vs. restricted environments illustrates what concept?

Gene–environment interaction (G×E).

In quantitative genetics, all non-inherited influences fall under what term?

Environment.

Mice bred with targeted mutations disabling specific genes are called what?

Knockout mice.

What is it called when adoptive children are matched with adoptive families similar to their birth families?

Selective placement.

Which of Mendel’s laws forms the basis for linkage?

The Law of Independent Assortment.

What is mating between genetically related individuals called?

Inbreeding.

Down syndrome results from what error during gamete formation?

Nondisjunction leading to trisomy 21.

What term refers to changes in gene expression mechanisms without altering DNA sequence?

Epigenetics.

An intermediate measurable variable between genes and behavior is called what?

An endophenotype.

SNP stands for what?

Single nucleotide polymorphism.

What is the interaction between alleles at different loci called?

Epistasis.

Research on adoptive siblings primarily indicates the influence of what?

Shared environmental effects.

What type of nonrandom mating results in similarity between spouses?

Assortative mating.

What disorder is the most commonly used example in behavioral genetics to illustrate gene–environment interaction?

PKU (Phenylketonuria).

Why is PKU considered such an important example in behavioral genetics?

It shows that a genetic disorder can be prevented entirely with an environmental intervention (a low-phenylalanine diet).

What causes PKU?

A mutation preventing proper metabolism of phenylalanine, leading to toxic buildup.

In a twin study with rMZ = .70 and rDZ = .50 for reading ability, what does this pattern suggest?

Both genetic and environmental influences are present, with moderate heritability.

What is the logic behind the twin design?

MZ twins share 100% of genes; DZ twins share 50%. Differences in similarity estimate genetic influence.

Why is the twin method preferred over family studies?

It better separates genetic and environmental effects due to known genetic similarity.

Why is it difficult to identify individual genes for psychological traits?

Traits are polygenic, with tiny effects per gene and large environmental contributions.

Give an example of an ethical dilemma in behavioral genetics.

Concerns about genetic discrimination (e.g., employment or insurance decisions).

What is eugenics?

The movement aimed at improving human populations by controlling reproduction.

What is the difference between positive and negative eugenics?

Positive promotes reproduction of “desirable” traits; negative restricts reproduction of “undesirable” traits.

What do selection studies examine?

How traits change across generations when individuals are selectively bred.

What are inbred strains?

Lines of animals genetically identical due to repeated brother–sister mating.

What are targeted mutations?

Deliberately engineered changes in specific genes.

What is a knockout organism?

One in which a specific gene is inactivated.

What is a transgenic organism?

An organism containing foreign DNA inserted into its genome.

What is pleiotropy?

When one gene affects multiple traits.

What is a genotype?

The genetic makeup of an organism.

What is a phenotype?

Observable traits resulting from genes and environment.

What is inclusive fitness?

Genetic success through personal reproduction plus aiding relatives’ reproductive success.

What is kin selection?

Evolutionary process favoring behaviors that benefit relatives.

What is an allele?

A variant form of a gene.

What is a polymorphism?

A genetic variation present in at least 1% of the population.

What is a dominant allele?

An allele expressed even when only one copy is present.

What is a recessive allele?

An allele expressed only when two copies are present.

What does homozygous mean?

Having two identical alleles for a trait.

What does heterozygous mean?

Having two different alleles for a trait.

What is a monohybrid cross?

A genetic cross examining one trait.

What do P1, F1, and F2 refer to?

Parental generation, first offspring generation, and second offspring generation.

What is a test cross used for?

Determining whether a dominant phenotype is homozygous or heterozygous.

What causes Huntington’s disease?

CAG triplet-repeat expansion in the HTT gene.

What is PKU?

A metabolic disorder caused by inability to break down phenylalanine.

What is incomplete dominance?

When heterozygotes show an intermediate phenotype.

What is inbreeding?

Mating between genetically related individuals.

What is hybrid vigor (heterosis)?

Increased fitness from crossing genetically diverse individuals.

What is assortative mating?

Nonrandom mating where partners are similar on certain traits.

What are complex traits?

Traits influenced by many genes and environments.

What are qualitative traits?

Traits that are categorical (e.g., present/absent).

What are quantitative traits?

Traits measured along a continuum (e.g., height).

What does polygenic mean?

Influenced by many genes.

What is the liability-threshold model?

A model proposing that a trait appears only once an underlying liability exceeds a threshold.

What does familial mean?

Tending to run in families.

What does genetic mean?

Caused or influenced by inherited DNA.

What does X-linked mean?

A gene located on the X chromosome.

What is an induced mutation?

A mutation caused by environmental factors.

Where is mitochondrial DNA inherited from?

Exclusively from the mother.

Who is Francis Galton?

Founder of behavioral genetics and early proponent of eugenics.

Who is Mendel?

The father of genetics who discovered basic inheritance laws.

What does a family study examine?

Trait similarity among relatives of varying genetic relatedness.

What does the adoption design test?

Genetic vs. environmental influences by comparing adopted relatives.

What does the twin design compare?

Trait similarity in MZ vs. DZ twins to estimate genetic influence.

Who counts as genetic vs. environmental siblings?

Genetic share DNA; environmental share household.

What is a restrictive environmental range?

When environmental differences are minimized, reducing environmental effects.

What is selective placement in adoption?

Matching adoptees with families similar to birth parents.

What are monozygotic twins?

Twins from one fertilized egg sharing 100% of genes.

What are dizygotic twins?

Twins from two eggs sharing ~50% of segregating genes.