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

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?

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?

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

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

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?

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

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?

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?

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

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

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

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

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

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

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