Question 1

A technique to confirm whether a particular candidate gene underlies a behavior is to alter the gene's expression. This can be done by
A) increasing gene activity by adding copies of the gene (knocking in).
B) increasing gene activity by disabling genes (knocking out).
C) increasing gene activity by microarray analysis.
D) all of the above.

Accepted Answer

Increasing gene activity can be achieved by adding copies of the gene, a process known as "knocking in." This technique directly alters the gene's expression to assess its role in specific behaviors or phenotypes.

Question 2

A region of DNA associated with a particular quantitative trait is called a quantitative trait locus (QTL). Which of the following statements about QTL analysis is FALSE?
A) There are usually only a small number of QTLs associated with any complex behavior.
B) A goal of QTL research is to identify the many genes underlying a trait and the extent to which each of them alters the trait.
C) Once a QTL has been identified, that region of DNA can be sequenced and compared to a database of DNA containing genes whose functions are known.
D) QTL analysis can help to identify candidate genes.

Accepted Answer

QTL analysis often reveals that complex behaviors and traits are influenced by many QTLs, not just a small number.

Question 3

Whitfield and colleagues (2003) found that nurse and forager bees showed significant differences in the expression of 2,200 of the 5,500 genes analyzed in the study. Their study made use of which of the following techniques?
A) hybridization
B) knocked in genes
C) knocked out genes
D) microarray analysis

Accepted Answer

Whitfield and colleagues' study on the gene expression differences between nurse and forager bees utilized microarray analysis, a technique that allows researchers to examine the expression levels of thousands of genes simultaneously to identify which genes are more or less active in different samples.

Question 4

The for gene that codes for PKG (an important cell signaling molecule) influences not only locomotion during foraging, but also readiness to respond to sucrose, and tendencies to habituate to repeated presentations of sucrose. This illustrates the principle that
A) a gene's activity may be modified by using RNAi.
B) genes operate in interacting networks.
C) one gene is usually dedicated to a particular, primary trait.
D) one gene usually affects several traits.

Accepted Answer

One gene can influence multiple traits, a concept known as pleiotropy. The example of the gene coding for PKG affecting various behaviors related to foraging and response to sucrose illustrates this principle.

Question 5

Social recognition between female mice depends on the protein products of four genes. Research by Choleris and colleagues (2004) demonstrated that in any single group of knockout mice in which one of the four components was lacking
A) the mutant mice couldn't distinguish a familiar mouse from a stranger.
B) the mutant mice refused to leave their nest without a familiar companion.
C) the strength of the social bond was weakened by a factor of almost exactly 25%.
D) the strength of the social bond was unchanged.

Accepted Answer

The research showed that without one of the four protein products, mutant mice lost the ability to recognize a familiar mouse from a stranger, indicating the importance of these proteins in social recognition.

Question 6

Prairie voles are monogamous; meadow voles are polygamous. It has been determined that male prairie voles have many more vasopressin receptors than do male meadow voles, and their receptors are concentrated in a reward system of the brain. Which of the following statements about voles is FALSE?
A) Coding sequences in the DNA of the vasopressin receptor gene of the two species of voles are 99% identical, thus the proteins produced by the gene in the two species is virtually identical.
B) Differences in DNA were found between the two species in the promoter region of the gene.
C) Different amounts of vasopressin surge in the brains of males of the two species following mating.
D) The male prairie vole associates the odor of his female mate with the feeling of reward.

Accepted Answer

The false statement is C because the difference in monogamous vs. polygamous behavior between prairie and meadow voles is primarily attributed to the number and distribution of vasopressin receptors in the brain, not to differences in the amount of vasopressin released following mating.

Question 7

Lower levels of hormones such as oxytocin and vasopressin have been found to be associated with human disorders such as
A) agoraphobia.
B) autism.
C) bipolar disorder.
D) depression.

Accepted Answer

Oxytocin and vasopressin are hormones that play significant roles in social bonding, trust, and relationship building. Lower levels of these hormones have been associated with autism, a disorder characterized by challenges in social interaction and communication.

Question 8

How quickly do immediate early genes become active once a nerve cell has responded to an appropriate stimulus?
A) milliseconds
B) minutes to hours
C) one day
D) one week

Accepted Answer

Immediate early genes become active within minutes to hours after a nerve cell has responded to an appropriate stimulus. They are among the first genes to be activated in response to physiological or environmental changes, acting as rapid responders in the cell's signaling pathways.

Question 9

Male cichlids may be either dominant or subordinate. Opportunities for a subordinate to rise in social status may occur rapidly, however, as when a dominant male is taken by a predator. Which of the following physical changes occurs first once the opportunity arises?
A) He acquires a territory.
B) He becomes brilliantly colored.
C) His body size increases.
D) His fertility level rises.

Accepted Answer

When a subordinate male cichlid has the opportunity to rise in social status, the first physical change that typically occurs is that he becomes brilliantly colored. This change is a signal of his new status and readiness to take on the roles and behaviors of a dominant male, including territory defense and mating.

Question 10

The finding that zenk activity increased in song sparrows whose territorial boundaries had been challenged suggests that
A) genes have much less to do with the production of behavior patterns than we believed to be the case 25 years ago.
B) the environment can continuously alter gene activity and, therefore, modify an organism's behavior.
C) while the environment influences when a gene becomes active, once that has happened, environment plays little role in further repetitions of the behavior.
D) All of the above are true.

Accepted Answer

The increase in zenk activity in response to territorial challenges in song sparrows indicates that environmental factors (such as territorial disputes) can influence gene activity, which in turn can affect behavior. This supports the idea that the environment can modify behavior through changes in gene activity.

Question 11

Levels of zenk mRNA in male zebra finches FAILED to increase when the subject male was
A) first exposed to the recorded song of another male zebra finch.
B) exposed to a second, unfamiliar male zebra finch.
C) with repeated exposures to the recorded song of the other zebra finch.
D) In all of the above cases. (Recorded song doesn't stimulate zenk activity.)

Accepted Answer

Repeated exposures to the recorded song of the other zebra finch lead to habituation, which results in no increase in zenk mRNA levels.

Question 12

Epigenetics involves
A) a stable alteration in gene expression without changes in DNA sequence.
B) processes such as DNA methylation and histone acetylation.
C) the regulation of the way genes are expressed without changing the proteins they encode.
D) all of the above.

Accepted Answer

Epigenetics encompasses all of these aspects: stable alterations in gene expression without DNA sequence changes, mechanisms like DNA methylation and histone acetylation, and the regulation of gene expression without altering the proteins produced by genes.

Question 13

DNA mythelation
A) consists of adding a methyl group to the cytosine bases in DNA.
B) makes the DNA less tightly coiled.
C) permanently alters gene expression in certain tissues once it has occurred.
D) renders gene expression easier.

Accepted Answer

DNA methylation involves the addition of a methyl group to the cytosine bases in DNA, which can affect gene expression by modifying the DNA structure and its accessibility to transcription machinery.

Question 14

By the end of the first week of life, the promoter of a glucocorticoid receptor in the pups of neglectful rat mothers was more methylated than the same gene in pups of nurturing mothers. This means that
A) pups of neglectful and nurturing mothers had some differences in the structures of their chromosomes that occurred after birth.
B) the pups of the neglectful mothers displayed a lessened response to stressful stimuli.
C) the pups of the neglectful mothers possessed more glucocorticoid receptors than the pups of nurturing mothers.
D) all of the above occurred.

Accepted Answer

The increased methylation of the glucocorticoid receptor promoter in pups of neglectful mothers suggests epigenetic changes (differences in gene expression regulation) that occurred after birth, not inherent structural differences in the chromosomes or an increase in glucocorticoid receptors.

Question 15

DNA methylation patterns can be affected by environmental factors, cause disease, be transmitted through generations and, potentially, influence evolution. This is illustrated by findings that when male rat embryos are exposed to the fungicide vinclozolin, they later
A) are the preferred mating partners by female rats, whether or not the females have been exposed to vinclozolin themselves.
B) experience a reduced risk of adult onset diseases.
C) have disrupted endocrine systems.
D) show higher fertility rates than unexposed males.

Accepted Answer

Exposure to the fungicide vinclozolin in male rat embryos has been shown to disrupt their endocrine systems, which can lead to various developmental and reproductive issues.

Quiz 3: Genetic Analysis of Behavior

A technique to confirm whether a particular candidate gene underlies a behavior is to alter the gene's expression. This can be done by

A region of DNA associated with a particular quantitative trait is called a quantitative trait locus (QTL) . Which of the following statements about QTL analysis is FALSE?

Whitfield and colleagues (2003) found that nurse and forager bees showed significant differences in the expression of 2,200 of the 5,500 genes analyzed in the study. Their study made use of which of the following techniques?

The for gene that codes for PKG (an important cell signaling molecule) influences not only locomotion during foraging, but also readiness to respond to sucrose, and tendencies to habituate to repeated presentations of sucrose. This illustrates the principle that

Social recognition between female mice depends on the protein products of four genes. Research by Choleris and colleagues (2004) demonstrated that in any single group of knockout mice in which one of the four components was lacking

Prairie voles are monogamous; meadow voles are polygamous. It has been determined that male prairie voles have many more vasopressin receptors than do male meadow voles, and their receptors are concentrated in a reward system of the brain. Which of the following statements about voles is FALSE?

Lower levels of hormones such as oxytocin and vasopressin have been found to be associated with human disorders such as

How quickly do immediate early genes become active once a nerve cell has responded to an appropriate stimulus?

Male cichlids may be either dominant or subordinate. Opportunities for a subordinate to rise in social status may occur rapidly, however, as when a dominant male is taken by a predator. Which of the following physical changes occurs first once the opportunity arises?

The finding that zenk activity increased in song sparrows whose territorial boundaries had been challenged suggests that

Levels of zenk mRNA in male zebra finches FAILED to increase when the subject male was

Epigenetics involves

DNA mythelation

By the end of the first week of life, the promoter of a glucocorticoid receptor in the pups of neglectful rat mothers was more methylated than the same gene in pups of nurturing mothers. This means that

DNA methylation patterns can be affected by environmental factors, cause disease, be transmitted through generations and, potentially, influence evolution. This is illustrated by findings that when male rat embryos are exposed to the fungicide vinclozolin, they later