Question 1

Similar concordance rates for a given trait in monozygotic (MZ)and dizygotic (DZ)twins suggests that the trait may be due to

Accepted Answer

Similar concordance rates in MZ and DZ twins suggest that the trait is likely influenced more by environmental factors, as MZ twins share more genetic material than DZ twins, so a genetic cause would typically result in higher concordance in MZ twins.

Question 2

As more genes are involved in determining a trait,what happens to the distribution of the trait in the general population?

Accepted Answer

The distribution of the trait tends to be a normal distribution as more genes are involved in determining the trait. This is because a normal distribution is the result of the combined influence of many factors, including genes, environment, and random chance. The more genes involved, the more likely the distribution will resemble a normal curve. It is important to note that the frequency of the trait in the general population may or may not change depending on the nature of the genes involved and their interactions.

Question 3

According to the concept of sexual selection,those characteristics that give males greater access to mates

Accepted Answer

The concept of sexual selection suggests that traits or behaviors that increase a male's ability to acquire mates will become more common over successive generations through natural selection. This is because the individuals with the advantageous traits are more successful at reproducing and passing on their genes to offspring.

Question 4

A strong piece of evidence that genes alone do not cause the vast majority of mental disorders is that genetic studies

Accepted Answer

Concordance rates for monozygotic (MZ) twins, who share 100% of their genes, being far below 100 percent for mental disorders suggest that factors other than genes, such as environment, play a significant role in the development of these disorders.

Question 5

Suppose that researchers discover the gene responsible for manic behavior.Assume that the alleles of the gene are represented by M and m and the gene is dominant/recessive.Which of the following represents the phenotype?

Accepted Answer

The phenotype is the observable trait or behavior that results from the expression of the gene. In this case, the gene is responsible for manic behavior, so the phenotype is manic behavior. The M and m alleles represent the different versions of the gene, but they do not directly affect the phenotype. The combination of the alleles determines the genotype, which may or may not result in the expression of the manic behavior phenotype. Therefore, options A and B are incorrect, and option D is incomplete and unclear.

Question 6

What is the most likely cause of a disorder if both monozygotic and dizygotic twins show a high concordance rate?

Accepted Answer

If both monozygotic and dizygotic twins show a high concordance rate, it suggests that shared environmental experiences have a strong influence on the disorder. If the disorder was caused by recessive or dominant genes, we would expect to see a higher concordance rate in monozygotic twins (who share more of their genes) compared to dizygotic twins. If the disorder was caused by different environmental experiences, we would expect to see a lower concordance rate in monozygotic twins compared to dizygotic twins.

Question 7

What is a phenotype?

Accepted Answer

A phenotype refers to the set of observable traits of an organism, which are determined by both its genetic makeup (genotype) and environmental factors. These traits can include physical characteristics, such as height or eye color, as well as behavioral or functional traits, such as the ability to digest certain foods or resistance to certain diseases.

Question 8

In evolutionary psychology,which of the following would be a good description of natural selection?

Accepted Answer

Natural selection is a process where certain traits or adaptations that give individuals an advantage in surviving and reproducing in a particular environment become more common in successive generations because they are genetically determined and passed down. This results in the evolution of species over time.

Question 9

Even when twin studies find that monozygotic twins have higher concordance rates than dizygotic twins,it is possible these results are not due to genetics but to the possibility that

Accepted Answer

Monozygotic twins are more genetically similar than dizygotic twins, but they may also be treated more similarly in their environments due to their identical physical appearance. This can contribute to higher concordance rates in MZ twins, even if genetics does play a role.

Question 10

Genes have alternative forms known as

Accepted Answer

Genes have alternative forms known as alleles. Phenotypes refer to the physical characteristics that result from the expression of an individual’s genes, while genotypes refer to the specific genetic makeup of an individual. Genosomes is not a valid term in genetics.

Question 11

Which of the following would be a legitimate summary of the role of genes in causing abnormal behavior?

Accepted Answer

While some genes have been identified as playing a role in certain mental disorders (such as the gene for Huntington's disease), the majority of mental disorders are believed to be caused by the interaction of multiple genes and environmental factors. Therefore, scientists have only identified the gene or genes responsible for a few rare forms of mental disorder, making choice B the most accurate summary. Choices A, C, and D are inaccurate as they either overstate the role of genes (A and D) or suggest that genes play no role at all (C).

Question 12

What is another name for a proband?

Accepted Answer

A proband is also referred to as an index case as they are the first person in a family or group to be diagnosed with a particular medical condition or disease, and subsequently undergo genetic testing or analysis.

Question 13

You are watching a video of John Bowlby in which he discusses his views on attachment.Later you are to write a summary of Bowlby's comments and include the major reason why he believes that attachments form.What will you write?

Accepted Answer

According to John Bowlby, the major reason why attachments form is that they have survival value. Bowlby believed that attachment behavior in infants was biologically programmed, as it would ensure the infant's survival by keeping them close to their primary caregiver who provides food, warmth, and protection. This innate attachment behavior would eventually lead to emotional bonds between the infant and their caregiver, which would form the basis of all future relationships.

Question 14

In twin studies the key comparison involves determining how many pairs of twins either have the same disorder or are free of the disorder; this involves the calculation of

Accepted Answer

Concordance rates are used in twin studies to determine how many pairs of twins share a disorder.

Question 15

Most theories developed by behavior geneticists to pin down genetic explanations for abnormal behavior assume that mental disorders are most likely

Accepted Answer

Most theories developed by behavior geneticists assume that mental disorders are polygenic, meaning that they are caused by multiple genes. This is supported by research on various disorders such as schizophrenia, bipolar disorder, and depression, which have been found to have a complex genetic basis involving many genes.

Question 16

Genes are small units of DNA,carriers of genetic information and

Accepted Answer

Genes are located on chromosomes.

Question 17

The major problem with family incidence studies that ask whether diseases "run in families" is that even when they find a higher prevalence of a certain illness in families with one ill proband,

Accepted Answer

The finding of a higher prevalence of a certain illness in families with one ill proband is consistent with both genetic and environmental causation. It does not allow for a determination if a single gene or multiple genes are involved, or if dominant or recessive genes are involved. Additionally, family incidence studies can include any type of family relationship, not just identical twins.

Question 18

Dr.Andrew Wakefield has speculated that the measles/mumps/rubella vaccination may be responsible for 12 cases of autism.A Danish study of half a million children found

Accepted Answer

The Danish study of half a million children found no evidence to support Dr. Andrew Wakefield's speculation that the measles/mumps/rubella vaccination is responsible for cases of autism.

Question 19

Adoption studies are important in behavior genetics because they help to

Accepted Answer

Adoption studies are important in behavior genetics because they help to provide evidence on genetic versus environmental contributions. By comparing adopted children to both their biological and adoptive parents, researchers can determine the extent to which genetic and environmental factors contribute to various traits and behaviors.

Question 20

In a study of twins,a researcher finds that 40 percent of dizygotic (DZ)twins and 40 percent of monozygotic (MZ)twins share a trait.What is the researcher most likely to conclude about the trait?

Accepted Answer

Since both dizygotic (DZ) twins, who share about 50% of their genes, and monozygotic (MZ) twins, who share nearly 100% of their genes, have the same 40% rate of sharing a trait, it suggests that the trait is not primarily determined by genetics. If the trait were genetically determined, we would expect a higher concordance rate in MZ twins compared to DZ twins.

Quiz 2: Causes of Abnormal Behavior

Similar concordance rates for a given trait in monozygotic (MZ) and dizygotic (DZ) twins suggests that the trait may be due to