Question 1

What term refers to different forms of the same gene?

Accepted Answer

Alleles are different forms of the same gene, which can result in variations in the genetic trait they influence.

Question 2

Which factor below would be part of the so-called nonshared environment?

Accepted Answer

Nonshared environment refers to the aspects of the environment that differ between individuals, even within the same family. Different friendships for siblings are an example of experiences that would differ between siblings, thus contributing to the nonshared environment.

Question 3

Which of the following is NOT indicated by a heritability statistic?

Accepted Answer

Heritability statistics indicate the proportion of variance in a trait attributable to genetic differences among individuals in a population. They do not directly inform about the interaction between genes and environments in producing behavior; instead, they focus on the genetic contribution to trait variability.

Question 4

A scientist interested in understanding how early experiences shape genetic expression studies

Accepted Answer

Epigenetics is the study of how behaviors and environment can cause changes that affect the way genes work. Unlike genetic changes, epigenetic changes are reversible and do not change the DNA sequence, but they can change how the body reads a DNA sequence. Early experiences can indeed shape genetic expression through epigenetic mechanisms.

Question 5

A high heritability coefficient can result when the trait ________ across individuals or when genes are important in a(n) ________ sense.

Accepted Answer

Heritability coefficients are higher when the trait shows significant variation among individuals and when genes play a crucial role in determining the trait in an absolute sense, indicating a strong genetic influence.

Question 6

Henry and Adam are identical twins. According to a study conducted by Bokenau and colleagues, similar levels of which trait are NOT likely to be influenced by their shared environment?

Accepted Answer

The answer of Henry and Adam are identical twins. According...

Question 7

When Brett was born, he and his identical twin were separated and have been living on opposite sides of the country ever since in houses of equal socioeconomic status yet with parents employing drastically different parenting styles. Which of the following are Brett and his twin MOST likely to share?

Accepted Answer

Identical twins, even when raised apart, tend to have similar IQ scores due to the strong genetic component of intelligence. Other factors like a sense of rebelliousness, level of anxiety, and music preference are more significantly influenced by environment and upbringing.

Question 8

Linda suffers from depression, whereas her brother Kyle is more emotionally stable. Which of the following genes is likely to differ between Kyle and Linda?

Accepted Answer

The 5-HTT gene, which is involved in the transport of serotonin, has been linked to depression. Variations in this gene can affect serotonin levels in the brain, influencing mood and emotional stability.

Question 9

Bryan has just been diagnosed with attention deficit hyperactivity disorder (ADHD). His sister Sarah has never been diagnosed with ADHD. Which of the following genes might differ between Bryan and Sarah?

Accepted Answer

DRD4 is a gene associated with dopamine regulation in the brain, which has been linked to ADHD in various studies. SSRI is not a gene but a type of medication (Selective Serotonin Reuptake Inhibitors), 5-HTT relates to serotonin transport but is less directly associated with ADHD, and APOA is not directly linked to ADHD.

Question 10

A(n) ________ searches for specific genes that are linked with particular personality attributes.

Accepted Answer

A genome-wide association study (GWAS) is designed to search for genetic variations across the entire genome that are associated with specific traits, including personality attributes. This approach does not focus on a single gene but rather scans the entire genome to identify small variations that correlate with particular traits.

Question 11

It is difficult to calculate the heritability of traits that

Accepted Answer

Heritability measures the proportion of variation in a trait due to genetic differences. If a trait does not vary across people, there is no variation to attribute to genetic differences, making heritability calculation impossible.

Question 12

Which of the following is true about gene-environment interactions and trait expression?

Accepted Answer

Option D is correct because it acknowledges the complexity of gene-environment interactions in determining trait expression. It recognizes that the same gene can result in different behaviors under different environmental conditions and that similar behaviors can arise from different genetic backgrounds due to the influence of the environment.

Question 13

What behavioral genetic research finding seems to support the conclusion that the effect of growing up in the same home environment is rather minimal?

Accepted Answer

The correlation of personality traits among adoptive siblings raised in the same family being around .05 suggests that the shared home environment has minimal impact on personality development, as these siblings do not share genetic material but only the environment, and yet show very low similarity in personality traits.

Question 14

What is the scientific benefit of knowing a trait's heritability coefficient?

Accepted Answer

The heritability coefficient measures the proportion of variance in a trait that can be attributed to genetic factors within a specific population and environment.

Question 15

How might a behavior geneticist explain the statistically significant finding that television watching is heritable?

Accepted Answer

Behavior geneticists often explain heritability in terms of underlying traits or propensities that are influenced by genetics, such as sensation seeking or lethargy, which could lead to behaviors like watching TV more often.

Question 16

As a result of Timothy's genes, he went through puberty later than his peers. Because he was much smaller than the other boys they tended to pick on him, and he fought back to protect himself. As a young adult, Timothy is more aggressive than his peers. This scenario illustrates that his aggression is

Accepted Answer

Timothy's aggression is shown as a result of both his genetic predisposition (late puberty) and how that predisposition influenced his social environment (being picked on and fighting back), illustrating an interaction between genetics and environment.

Question 17

In the past, some psychologists have concluded that shared family environments have little or no effect on personality development. Recent research has cast doubt on such conclusions by finding that

Accepted Answer

Recent research suggests that shared environments can influence personality when assessed through direct behavioral observation, challenging earlier conclusions that downplayed the role of shared family environments.

Question 18

In which sample would you expect the heritability of IQ to be the lowest?

Accepted Answer

Heritability of IQ tends to be lower in populations under significant environmental stress or variability, such as those in low socioeconomic status. This is because environmental factors have a larger role in influencing IQ, reducing the relative influence of genetics.

Question 19

If there is no phenotypic variation in a trait, then the heritability of that trait will be approximately

Accepted Answer

Heritability measures the proportion of variation in a trait that can be attributed to genetic variation among individuals. If there is no phenotypic variation in a trait, it means all observed variation is due to environmental factors, not genetics, making the heritability 0.

Question 20

A recent study indicates that a serotonin-related genetic allele seems to influence the development of depression in conjunction with

Accepted Answer

The study suggests that the serotonin-related genetic allele interacts with stressful life events to influence the development of depression, highlighting the gene-environment interaction.

Quiz 9: Genetics and Evolution: the Inheritance of Personality