EXAM AND PRACTICES
Indicate which equation equals the correlation: DZ twins reared together rDZ = 0.5*a2 + c2 c2 a2 + c2 a2 a2 + c2 + e2
0.5*a2 + c2
If two traits have a phenotypic correlation (r) of .50, it would be impossible for the genetic correlation (rA) to be 1.0. false
A dog breeder crosses two dogs that are heterozygous for brown coats. Some of the puppies have brown coats, and some have black coats. Assuming that coat color is controlled by a single gene, which of the following statements is most likely true? Correct Answer The allele for brown coat is dominant to the allele for black coat.
In humans, the ability to taste the bitter chemical PTC is controlled by a single gene. The tasting gene (T) is dominant to the non-tasting gene (t). Which of the following genotypes is correctly labeled? TT - homozygous dominant
A female fish is homozygous dominant for both fancy fins (F) and shiny scales (S). She is crossed with a male who is heterozygous for both traits. What are the genotypes of these fish? (female; male) FFSS; FfSs
Of individuals with a mental disorder, ____% will meet criteria for a second disorder. 66
A gene knockout alters DNA, so it is heritable. true
A national study finds that kids who play music are less likely to experiment with drugs. You decide to look at this relationship with a co-twin control study. Which of the following results would suggest that music engagement prevents drug use? Within an MZ pair, if one twin plays music and the other doesn't, the one who plays music would be less likely to try drugs.
A liver cell and a skin cell in the same person have the same genetic sequences, but perform very different functions. Which of the following best explains how this is possible? Different genes are activated in the liver vs the skin cell.
A study of agreeableness finds rMZa (MZ twins reared apart) = .30. What is the influence of shared rearing environment (c2)? There is not enough information to compute it.
A male bird is homozygous recessive for both wacky wings (w) and flashy feathers (f). He is crossed with a female who is homozygous dominant (normal wings and normal feathers) for both traits.What are the genotypes of these birds? (male; female) wwff; WWFF
In horses, black coloring (B) is dominant, and chestnut coloring (b) is recessive. A homozygous black horse crosses with a chestnut horse. What percentage of offspring are expected to be chestnut? 0%
A study of agreeableness finds rMZa (MZ twins reared apart) = .30. What is the heritability (a2)? .30
Considering general trends across twin studies, which of the following statements is true (select all that are true)? When c2 is present, it tends to be early in life Nonshared environment (e2) seems to be more important than shared environment (c2)
A twin study of attention problems finds rMZ = .75 and rDZ = .40 What is the influence of shared rearing environment (c2)? .05
A twin study of introversion finds rMZ = .48 and rDZ = .24 What is the effect of shared rearing environment (c2)? .00
A twin study of introversion finds rMZ = .48 and rDZ = .24 What is the effect of nonshared environment (e2)? .52
Which of the following is a type of sequence genetic variation (select all that apply)? single nucleotide polymorphism (SNP)
A woman who has a sex-linked recessive trait has a son with a man who does not have that trait. Which of the following is true about their son? There is a 100% chance he will be affected.
Which category of gene-environment correlation (rGE) is related to the concept of genetic nurture? Passive rGE
A woman with mild symptoms of myotonic muscular dystrophy has a daughter with a very severe form of the disease. Which of the following statements is most correct? This is an example of anticipation.
Twins are more likely to have a psychiatric diagnosis compared to non-twins. false
Adoptive siblings who are reared in the same home share which sources of resemblance (select all that apply): shared environmental influences
Indicate which equation equals the correlation: Adoptive siblings reared together rAS = c2
Adoptive studies can be informative about the importance of environmental influences on behavior. This is unlike studying a biological family, where a child's genotype is correlated with (select all that apply): the parent's genotype the environment created by the parent
The pedigree below tracks the presence of attached earlobes through a family's generations. Having attached earlobes is an autosomal recessive trait. Pedigree of family with attached earlobes If individual III-6 mated with a man who was homozygous for unattached earlobes, what is most likely to be true regarding their children? All females children will have unattached earlobes, and all the male children will have attached earlobes. The children would have partially attached earlobes. All of their children would have attached earlobes. All of their children would have unattached earlobes.
All of their children would have unattached earlobes.
In an inbred strain study, which result suggests genetic influences on a behavior? Differences across strains
Although most tortoiseshell cats are female, a litter of kittens will occasionally contain a male tortoiseshell. Which of the following can explain tortoiseshell coat color in a male kitten? the male kitten has an extra X chromosome
In buffalo, being boring (B) is dominant to being busy (b). A true-breeding, busy male is crossed with a true-breeding, boring female. Only Bb
An adoption study of screen time finds rAS (Adoptive siblings) = .20 What is heritability (a2)? Correct Answer There is not enough information to compute it.
Method that tests a phenotype's relationship to variants across the genome GWAS
An adoption study of screen time finds rAS (adoptive siblings) = .20 What is the influence of shared rearing environment (c2)? .20
An adoption study of screen time finds rBSa (Biological siblings raised apart) = .15 What is heritability (a2)? .30
An adoption study of screen time finds rBSa (Biological siblings raised apart) = .15 What is the influence of shared rearing envrionment (c2)? There is not enough information to compute it.
Even though they have different heritabilities, mild and severe intellectual disability are influenced by the same genes. false
Candidate-gene X environment studies (such as the study showing that the HTTLPR genotype effects depend on the number of life events) provide the best evidence that gene-environment interactions are important for psychology. false
Heritability is a measurement that estimates the proportion of: phenotypic variation in a group that can be attributed to genetic variation
Characteristics shared by adopted children and their biological parents are mostly genetic while their similarities with adoptive parents reflect environmental influences.
A twin study of attention problems finds rMZ = .75 and rDZ = .40 What is the heritability (a2)? .70
Common variants are generally considered those that have MAF of less than 1% in the population. false
Which of the following methodological issues are relevant to adoption studies? selective placement represenativeness prenatal environmental effects
Complex disorders are typically influenced by (select all that apply): environmental effects many variants, each with a small individual effect
Which descriptions describe gene-environment interaction (GxE) (select all that apply)? Which environment people experience is related to genetic makeup The effect of environment depends on genetic differences When reaction to environments is related to to genetic differences When exposure to environments is related to to genetic differences Genetic control of sensitivity to the environment
Correct! The effect of environment depends on genetic differences Correct! When reaction to environments is related to to genetic differences Genetic control of sensitivity to the environment
Area of psychology concerned with how differences in our genomes contribute to our behavioral differences behavior genetics
Describes the probability that a relative will have a disease given that a proband has it concordance
Method that tests whether a particular variant causes a phenotype candidate gene studies
Designing a candidate gene study involves which of the following (select all that apply)? Having knowledge of genetic variants that influence the proposed biological mechanism Having a hypothesis about the biological mechanism underlying the phenotype
There is evidence for gene-environment interactions (GxE) from studies that use polygenic scores as aggregate measures of genetic influences. true
Epigenetic modifications can be passed down to successive generations. true
A dog breeder crosses two dogs that are heterozygous for brown coats. Some of the puppies have brown coats, and some have black coats. Assuming that coat color is controlled by a single gene, which of the following statements is most likely true? The allele for brown coat is dominant to the allele for black coat.
Epigenetic modifications change gene expression and translation
The average heritability of intelligence is about 50%. true
From childhood to adulthood, the heritability of intelligence increases
GWASs for major depressive disorder were more successful with smaller sample sizes than GWASs for schizophrenia. false
GWAS studies to date are overwhelmingly based on populations of African ancestry. false
In order to develop some disorders, a person require both a diathesis (genetic propensity) and a stress (an environmental exposure). The diathesis itself it not sufficient to develop the disorder. This is an example of GXE active rGE evocative rGE passive rGE
GXE
When is linkage most likely to occur? For genes that are close together on the same chromosome
Gene silencing alters DNA, so it is heritable. false
An index of strength of the linear relationship between two continuous scores correlation
Having this type of twin runs in families and varies by mothers' ancestry dizygotic
In a GWAS, what is an indirect association? When a genome-wide-significant SNP is correlated with the causal allele
Hemophilia is an X-linked recessive trait. A non-hemophiliac father and and a hemophiliac mother have a son. What is the percent chance that the son will be a hemophiliac? 100%
Which gene-environment interactions were discussed in lectures? involving alcohol use and permissiveness of the environment involving antisocial behavior and adverse home environments involving depression and life events involving cognitive ability and socioeconomic status
Hemophilia is an X-linked recessive trait. A non-hemophiliac father and and a hemophiliac mother have a son. What is the percent chance that the son will be a hemophiliac? 100%
A traumatic brain injury would be an example of a(n) ________ cause of intellectual disability. organic
Human eye colors are found on a spectrum that ranges from completely pigmented (dark brown eyes) to a complete lack of pigment (light blue eyes). Which type of non-Mendelian inheritance does human eye color exemplify and why? Polygenic inheritance; it involves multiple genes coding for a trait that falls within a wide spectrum
Substance use disorders are usually clustered with ___________ disorders. Exernalizing
Human eye colors are found on a spectrum that ranges from completely pigmented (dark brown eyes) to a complete lack of pigment (light blue eyes). Which type of non-Mendelian inheritance does human eye color exemplify and why? Polygenic inheritance; it involves multiple genes coding for a trait that falls within a wide spectrum
What is comorbidity (select all that apply)? When two disorders occur in the same person at the same time When two disorders occur in the same person sequentially
If MZ twins are treated more similarly than DZ twins and that similar treatment affects a phenotype of interest, which assumption would be violated? equal environments assumption.
A genetic correlation (rA) < 1.0 for two traits indicates that there are some genetic influences that are unique to at least one of the traits. true
If MZ twins are treated more similarly than DZ twins and this similar treatment affects the twin correlations, how might this bias our estimates of genetic and environmental influences? The estimate of genetic influences may be too high
In chickens, the allele for black feathers (A) is dominant over the allele for red feathers (a). Which of the following pairs of terms are correctly matched? aa - genotype; red feathers - phenotype
If a child has a genetic predisposition towards aggressive behavior, they may also be more likely sign up for formal training in fighting techniques compared to a child to is very timid due to active rGE
The two-group model of cognitive disabilities suggests that intellectual disability is heterogenous
If a child inherits a genetic propensity to consume a lot of calories from their parents, and also live in a household that eats large meals on average, this would be an example of passive rGE
In dogs, being clumsy (C) is dominant to being cool (c), and being dazzling (D) is dominant to being docile (d). A female dog that is heterozygous for both the C and D trait is mated with a male dog that is also heterozygous for both traits. Both the C and D traits assort independently from one another. What is the probability that they will have an offspring that is clumsy and dazzling? 9/16
If a trait is highly heritable in one population, it will necessarily be highly heritable in a different population. false
Example of A candidate gene discussed in class 5HTTPLPR
If an adoption study includes adoptees who have a lot of contact with their birth parents, how might this affect estimates of genetic and environmental influences? The estimate of genetic influences may be too high
What are some phenotypes discussed in lecture that show shared environmental influences in childhood (select all that apply)? conduct disorder intelligence
If biological sibling pairs have more correlated SAT scores compared to adoptive sibling pairs, on average, this would be evidence that: there are additive genetic influences that affect SAT performance
Suppose you cross a pure-breeding, black-coated dog with curly fur to a pure-breeding, yellow-coated dog with straight fur. In the F1 generation, all the puppies have straight, black coats. Next, you interbreed the F1 dogs with another to get an F2. If coat color and coat texture are controlled by two genes that assort independently, what fraction of the F2 puppies are expected to have yellow, straight fur? 3/16
If the same genes are influencing a trait at different ages, then the heritability will be the same at those ages. false
Twins score higher in social closeness than non-twins because they have a sibling the same age as them. false
If twins discordant on an environmental factor show a difference in an outcome, it is consistent with the hypothesis that the environmental factor causes the outcome. true
Phenotype that is caused by more than one gene polygenic
In a pea plant, tall (T) is dominant to short (t), and green peas (G) are dominant to yellow peas (g). A tall plant with yellow peas (Ttgg) is crossed with a short plant with green peas (ttGg). Both the T and G traits assort independently from one another. What is the chance that the offspring will be short with yellow peas? 1/4
Bob's parents have very high polygenic scores of music talents. They both became successful musicians. Because of their jobs, there are many instruments in the house that Bob grew up in. Consequently, Bob started at a very young age to play with those instruments and became a good guitarist in a high school band. Which of the following effects best explains the experience of Bob? Genetic nurture
In a species of birds, blue feathers (B) are incompletely dominant to the gene for white feathers (b). Individuals that are heterozygous (Bb) have blue-tipped feathers. A bird with blue-tipped feathers is crossed with a white bird. What is the chance that the offspring will have blue feathers? 0%
There is evidence for gene-environment interactions (GxE) from quantitative genetic designs. true
In camellia flowers, petal color is controlled by codominance. When a red flower is crossed with a white flower, all of the offspring are covered in both red and white petals. 50% of the offspring will be red, and 50% of the offspring will be red-and-white
____________ disorders include antisocial personality disorder, conduct disorder, and substance use disorders. Externalizing
In chickens, the allele for a pea comb (A) is dominant to the allele for a single comb (a). A mother with the genotype Aa and a father with the genotype Aa produce an offspring. What is the percent chance that the offspring will have a single comb? 25%
Two traits can be highly genetically correlated even if they each have only moderate heritabilities. true
In genetics, what does a genotype of Hh signify? Heterozygous; one dominant allele and one recessive allele A heterozygous individual (Hh), also known as a carrier, has a genotype with one dominant allele (H) and one recessive allele (h).
Which of the following is not a recognized implication of genetic nurture? Demonstrating gene-environment interactions for certain traits
In humans, the gene for curly hair (H) is incompletely dominant to the gene for straight hair (h). Individuals that are heterozygous (Hh) have wavy hair. Two wavy-haired parents have a child. What is the likeliness that the child will have wavy hair? 1/2
A study of middle-school twins finds that performance on both math and vocabulary tests is heritable, but the heritability of math performance is higher than the heritability of vocabulary performance. Which of the following statements would be supported by these results (select all that apply)? Some of the variation in both math and vocabulary performance is attributable to genetic variation.
In leopards, being shy (S) is dominant to being sassy (s), and being timely (T) is dominant to being tardy (t). A female leopard that is heterozygous for both the S and T trait mates with a male leopard that is also heterozygous for both traits. Both the S and T traits assort independently from one another. What is the probability that they will have an offspring that is sassy and timely? 18.75%
What strategies are commonly used to deal with population stratification (select all that apply)? Statistically control for ancestry Look at homogenous populations (e.g., all European ancestry)
In monkeys, being playful (P) is dominant to being paranoid (p). A heterozygous female is crossed with a homozygous dominant male. What are the possible genotypes of their offspring? PP and Pp
The heritability statistic applies to: a population
In pea plants, the allele for smooth pods (S) is dominant over the allele for constricted pods (s). Which of the following pairs of terms are correctly matched? ss - genotype; constricted pod - phenotype
In cats, being awesome (A) is dominant to being average (a), and being bashful (B) is dominant to being boring (b). A male cat that is homozygous dominant for the A trait and heterozygous for the B trait is mated with a female cat that is homozygous recessive for both. Both the A and B traits assort independently from one another. What is the probability that they will have an offspring who is heterozygous for both traits? 50%
In rabbits, brown fur (B) is dominant to white fur (b) and short fur (H) is dominant to long fur (h). A brown, long-furred rabbit (Bbhh) is crossed with a white, short-furred rabbit (bbHh). Both the B and H traits assort independently from one another. What percentage of the offspring will be brown with long fur? 25%
If twins discordant on an environmental factor do not show a difference in an outcome, it suggests there is no causal relationship between the environmental factor and the outcome. true
Indicate which equation equals the correlation: Adoptee with adoptive parent r = c2
Indicate which equation equals correlation: MZ twins reared together rMZ = a2 + c2
Indicate which equation equals the correlation: Adoptee with biological parent r = 0.5*a2
Genetically informative samples provides evidence about the importance of environment. true
Indicate which equation equals the correlation: Biological child with biological parent r = 0.5*a2 + c2
Indicate which equation equals the correlation: DZ twins reared apart rDZa = 0.5*a2
Indicate which equation equals the correlation: Biological siblings reared apart rBSa = 0.5*a2
The eugenics movement sought to promote improvement of human society by influencing who... (select all that apply) reproduced
Indicate which equation equals the correlation: Biological siblings reared together rBSt = 0.5*a2 + c2
In pea plants, the allele for smooth pods (S) is dominant over the allele for constricted pods (s). Which of the following pairs of terms are correctly matched? ss - genotype; constricted pod - phenotype
Indicate which equation equals the correlation: MZ twins reared apart rMZa = a2
Environmental influences that lead siblings to be uncorrelated nonshared
It is possible to have a genetic correlation (rA) > 1. false
Most psychological disorders show heritability estimates around 30%. false
LD-score regression can be used to estimate: genetic correlations
Which of the following methodological issues are relevant to twin studies? equal environments assumption prenatal environmental effects represenativeness
Linkage disequilibrium (LD) patterns differ across ancestry. true
In a pea plant, Yellow (Y) is dominant to green (y), and Round (R) is dominant to wrinkled (r). For the cross of YyRr x yyrr, how many unique phenotypes are possible (here, a phenotype is defined by both the color and texture of the offspring)? 4
Linkage disequilibrium is when an allele of one SNP tends to occur with the allele of another SNP in a population. true
Which of the following is a reason for lack of replication in candidate gene studies, including candidate gene by environment interaction studies, that we discussed in class (select all that apply)? Capitalizing on chance Publication bias Low power due to small sample sizes
Male body cells only have one X chromosome, while females have two X chromosomes. It is hypothesized that if both X chromosomes of a female were active and functioning, they could cause metabolic dysfunction. Which of the following helps prevent this from occurring? X-inactivation "switches off" one of the X chromosomes
Which has higher heritability? Mild intellectual disability Severe intellectual disability
Mild intellectual disability
Red-green color blindness is an X-linked recessive trait in humans. A colorblind woman and a non-colorblind man have a daughter; what is the probability that the daughter is colorblind? 0%
Minor allele frequency (MAF) refers to the frequency at which the second most common allele occurs in a given population true
Co-twin control studies suggest that cannabis use causes lasting cognitive impairments. false
Nonshared environmental influences can include shared experiences if the children respond differently to those experiences true
A disorder due to an aneuploidy (e.g., abnormal number of chromosomes, typically occurring in one member of a family) would be an example of a(n) ________ cause of organic
Ocular albinism is an X-linked recessive trait that causes a lack of pigmentation in the eyes. 0%
The likelihood you will find an effect if it exists power
One reasons that GWAS hits for polygenic traits are often not directly useful for functional follow-up is that there are 100's of genes involved in polygenic traits, so a single gene will not provide the whole picture true
Families members tend to be similar to each other for IQ scores due to additive gene influences and shared environment
People with a hereditary disorder called Marfan syndrome may have a set of symptoms that can all be traced back the mutation of a single gene: Unusually tall height Thin fingers and toes Dislocation of the lens of the eye Heart problems (in which the aorta, the large blood vessel carrying blood away from the heart, bulges or ruptures). pleiotropy
One major contribution of the GWASs of educational attainment was the concrete policy suggestion that the authors made based on their findings. false
Polygenic risk scores have been found to be most predictive when using what proportion of genetic variants? All genetic variants
What is the equal environments assumption in a twin study? MZ and DZ twins do not differ in the degree to which they share environments that make twins similar
Process that produces incorrect numbers of chromosomes in cells nondisjunction
The figure below depicts two different IQ distributions, with the same standard deviation. The mean IQ in 1932 is 103 and the mean IQ in 1997 is 120). This figure demonstrates which of the following? the Flynn effect
Reared-apart twins about as similar as reared-together twins for most traits studied. true
Psychological disorders are (select all that apply) highly comorbid often heterogeneous highly prevalent
Red-green color blindness is an X-linked recessive trait in humans. If the parental genotypes are XcX for the mom and XcY for the dad, select all possible phenotypes in the children. Non-colorblind Female Correct! Colorblind Female Correct! Non-colorblind Male Correct Answer Colorblind Male
Which is the most heritable? Substance use disorders in adulthood
Red-green colorblindness is a recessive X-linked trait in humans. Which of the following pairs of parents is most likely to produce a daughter with red-green colorblindness? A carrier mother and a colorblind father
____________ disorders include bipolar disorder and schizophrenia. Thought
Reprogramming refers to removal of epigenetic changes in gametes. true
Twins tend to be born prematurely and have lower birth weight than non-twins. true
Siblings share 50% of their genes while fraternal twins share 50 % and identical twins share 100 % of their genes (on average).
Imagine that you are a rabbit breeder with two purebred rabbits, a male with black fur and a female with tan fur. When you cross your rabbits, all of the F1 kits (baby rabbits) have tan fur. Which trait is dominant, and which is recessive? Tan fur is dominant, while black fur is recessive
Sickle-cell anemia is a recessive trait in humans. In order to express the disease, an affected individual must inherit two recessive alleles (ss). What is the probability that the offspring of two heterozygous parents will also be heterozygous? 1/2
A father with the genotype AB at a locus has two children with a mother who has the genotype CD at that locus. The two children have genotypes AC and BC. What is the children's IBD score at this locus? 1
Studies testing the equal environments assumption have concluded that its violation is a major source of bias in conclusions about heritability. false
What is population stratification? Systematic difference in allele frequencies due to different ancestry
Systematic difference in allele frequencies due to different ancestry Pleiotropy is when one gene affects multiple phenotypes.
When an allele of one SNP tends to occur with the allele of another SNP in a population linkage disequilibrium
Targeted mutations deal with natural variation. false
Which of the following is a type of structural genetic variation (select all that apply)? Aneuploidy Insertion variable number tandem repeat (VNTR)
The Common Disease-Common Variant Hypothesis (CDCVH) hypothesis suggests that common diseases should be associated with many variants of small effects. true
Type of allele that produces a phenotype when either one or two copies are present dominant
The assembly of amino acids into peptide chains on the basis of information encoded in messenger RNA translation
An individual who is heterozygous for an allele causing a recessive trait carrier
The epigenetic clock examines the difference between your ________ and your __________ chronological age; biological age
The set of two alleles that one inherits at a particular locus genotype
The exchange of genetic material on homologous chromosomes recombination
If the genetic correlation (rA) for two traits is high, then the rE (the environmental correlation) must be low. false
The genetic signal in the GWASs for educational attainment reflects genetic effects on which of the following (select all that apply)? indirect effects of parents' education and socioeconomic status personality cognition
Heritability estimates the proportion of phenotypic differences in a population that can be explained by genetic differences in that population.
The presence of an abnormal number of chromosomes in a cell aneuploidy
In the module on heritability, we used the fact that children share 50% of their alleles with each parent to compute heritability. From which of Mendel's laws does this fact come (fill in the blank)? law of segregation
The process of producing two identical copies of DNA from one original DNA molecule replication
In a pea plant, Yellow (Y) is dominant to green (y), and Round (R) is dominant to wrinkled (r). For the cross of YyRr x yyrr, what is the proportion of possible offspring who express a recombinant set of phenotypes? 0.5
The validity of which method depends on both the equal environment assumption and the representativeness assumption? twin studies
A twin study of introversion finds rMZ = .48 and rDZ = .24 What is the heritability (a2)? .48
Twins who share a single chorion must be: monozygotic
In an inbred strain study, which result suggests environmental influences on a behavior? Differences within strains
What is synteny homology? When parts of chromosomes in one species have same genes in same order as in another species
The ability to prevent symptoms of phenylketonuria (PKU) through environmental intervention (i.e., diet) from becoming problematic demonstrates which of the following concepts? Even highly heritable characteristics are modifiable.
What is the Turkheimer effect? Heritability of IQ is higher for children growing up with higher socioeconomic status (SES).
As sample sizes for psychiatric disorders have grown, GWASs have mostly found all the genes that explain the heritability estimates from family studies. False
What is the central dogma of molecular biology? An explanation of the flow of genetic information in a biological system
Which descriptions describe gene-environment correlation (rGE) (select all that apply)? When exposure to environments is related to to genetic differences Genetic control of sensitivity to the environment When reaction to environments is related to to genetic differences The effect of environment depends on genetic differences Which environment people experience is related to genetic makeup
When exposure to environments is related to to genetic differences Which environment people experience is related to genetic makeup
Genetic influence on substance use disorders are more related to psychiatric disorders than are genetic influences on substance use. true
When one gene (or genetic variant) has multiple phenotypic effects polygenic
There are shared genetic influences on substance use disorders involving different substances (e.g., alcohol, nicotine, cannabis). true
When some individuals with a risk allele for a disorder do not express any symptoms incomplete penetrance
____________ disorders include major depression, anxiety, panic disorder, and phobias. Internalizing
When the heterozygote shows a blended phenotype incomplete dominance
There are substance-specific genetic influences on substance use disorders involving different substances such as alcohol and nicotine. true
When the phenotype depends on an interaction of alleles at the same locus allelic interaction
A mutation on chromosome 12, in the ALDH2 gene, leads to an inability to properly metabolize alcohol. Which genotype would have the strongest protection against developing alcohol use disorder? having two copies of the mutation
When there is a range of severity of symptoms across individuals with a risk allele for a disorder variable expressivity
Which mutation would be classified as a synonymous mutation? CGU -> CGA
Which mutation would be classified as a nonsynonymous mutation? UUC -> UUG
If a child inherits a genetic propensity to consume a lot of calories from their parents, and also live in a household that eats large meals on average, this would be an example of passive rGE
Which of the following answer choices would be a sex chromosome aneuploidy in a human? an egg contains two X chromosomes.
A research study reveals that a measure of disordered eating has a heritability estimate of .40 in a group of young women. This finding best supports which of the following conclusions? Approximately 40% of the variance in disordered eating is attributed to genetic factors within this group.
Which of the following are advantages of animal studies over human studies (select all that apply)? The ability to control the environment The ability to manipulate genes Animals have shorter lifespans and can create more offspring
Which of the following were findings discussed in Sam Freis' guest lecture on twin cell-phone location data (select all that apply)? MZ twins shared more space than DZ twins.
Which of the following are explanations for the lack of replication of candidate gene studies (select all that apply)? multiple testing Correct! low power indirect replication
Red-green color blindness is an X-linked recessive trait in humans. A colorblind woman and a non-colorblind man have a son; what is the probability that the son is colorblind? 100%
Which of the following are limitations of knockout studies (select all that apply)? The knocked out gene is inactive throughout lifespan, so the animal could compensate Some knockouts are not viable
Gene hunting methods have demonstrated that most forms of psychopathology are highly polygenic
Which of the following are quantitative genetic designs (select all that apply)? selection study inbred strain study
Sam Freis gave a guest lecture about her study looking at twin similarity with cell-phone location data. What assumption was she interested in testing? equal environments
Which of the following are reasons that animal studies can be informative about the genetics of human traits (select all that apply)? animals and humans respond similarly to a drug synteny homology animals and humans show similar neural responses to some stimuli
In corn, smooth kernels (K) are dominant to wrinkled kernels (k). A farmer crosses two corn plants that are heterozygous for kernel texture. What are the odds that the offspring will have smooth kernels? 3/4
Which of the following are true of dominant and recessive alleles? (select all that apply): Dominant alleles mask the expressive of recessive alleles Dominant and recessive alleles can be found in the same individual
Which are implications of the Common Disease-Common Variant hypothesis (select all that apply)? Low penetrance of causal variants Many causal variants
Which of the following statements is true about nondisjunction during meiosis? Nondisjunction can result in aneuploid cells.
Which of these factors does not provide evidence that the disorder may have a genetic cause? Correct! Individuals that live with an affected individual are more likely to also exhibit the disorder.
Which of the following statements regarding heritability is NOT true? Heritability is a fixed property of a trait.
A genetic correlation (rA) = 1.0 for two traits indicates that all the genetic influences on one trait also influence the other trait. true
Which statement best describes the relationship between genotype and phenotype? Genotype determines phenotype, but with influence from the environment
Using this diagram, match the values in the figure with the correct descriptions: a2 for shyness at 14 months a2 for shyness at 20 months e2 for shyness at 14 months e2 for shyness at 20 months rA rE
a2 14 = .58 a2 20 = .45 e2 14 = .44 e2 20 = .55 rA = .78 rE = -.08
The pedigree below tracks the presence of dimples through a family's generation. Having dimples is an autosomal dominant trait. Pedigree of family with dimples What is the phenotype of individual III-4? Dimples DD dd No dimples
dimples
If a child has a genetic predisposition towards aggressive behavior and tends to start fights with their classmates, the fact that other students are more likely to respond aggressively to this child compared to a timid child would be an example of GxE active rGE passive rGE evocative rGE
evocative rGE
Indicate which effects are present in the figure below (select all that apply): gene-environment interaction gene-environment correlation environmental effect genetic effect
genetic effect
Match the correct definitions to the terms. shared environment - environmental influences that make family members similar
nonshared environment - environmental influences that make family members dissimilar
Who was deemed "unfit" during the eugenics movement (select all that apply)? people who were LGBTQ+ people with mental disabilities people who were poor immigrants
people who were LGBTQ+ people with mental disabilities people who were poor immigrants
Cross between parents differing in a single trait monohybrid
variants with MAF > 1% in population common variant