Question 1

The consistent parenting style exhibited by parents toward all their children would represent a _____ for the children.

Accepted Answer

A shared environmental experience refers to experiences that siblings have in common, such as growing up in the same household with the same parents. The consistent parenting style exhibited by parents toward all their children would be a shared environmental experience, as all children would have been exposed to it in the same way. Genetic effects refer to the impact of genes on a trait or behavior, which is not relevant in this scenario. Nonshared environmental experiences refer to experiences that are unique to each individual, such as having a different teacher or different friends, and are also not relevant in this scenario. The crossing over effect refers to a genetic process that occurs during meiosis, and is not relevant in this scenario.

Question 2

A high concordance rate between identical twins for schizophrenia would suggest that the disorder

Accepted Answer

A high concordance rate between identical twins for schizophrenia suggests that there is a genetic basis for the disorder. This is because identical twins share 100% of their genetic material, and therefore, if one twin develops schizophrenia, it is likely that the other twin will as well if genetics play a significant role in the disorder.

Question 3

If a physician wanted to get a visual image of a developing fetus' limbs,her best option would be to use a(n)

Accepted Answer

Ultrasound technology is commonly used to create visual images of a developing fetus. It is a noninvasive and safe method for observing and assessing fetal growth, including the development of limbs. Preimplantation genetic diagnosis, chorionic villus sampling, and amniocentesis are all invasive procedures that involve collecting and analyzing fetal tissue or fluid for genetic testing, but they do not provide direct visual images of fetal development.

Question 4

Despite the fact that it is the result of recessive genes,some carriers of sickle-cell disease possess both normal and sickle-shaped blood cells.This phenomenon is best explained by

Accepted Answer

Incomplete dominance occurs when the heterozygous phenotype is an intermediate blend of the two homozygous phenotypes. In the case of sickle-cell disease, carriers with both normal and sickle-shaped blood cells have an intermediate phenotype because they only have one copy of the sickle cell gene. This results in some normal blood cells and some sickle-shaped blood cells.

Question 5

If genes alone contribute to a trait,which of the following patterns of correlations would be observed?

Accepted Answer

A correlation of 1.00 for identical twins raised together indicates that the trait is entirely determined by genes, as identical twins have the same genetic makeup. The lower correlation for identical twins raised apart indicates some environmental influence. A correlation of .50 for fraternal twins raised together indicates that genes are a moderate contributor. The lower correlation for fraternal twins raised apart also suggests some environmental influence.

Question 6

Tony and Ling are both carriers of the same defective gene for a genetic disorder.As knowledgeable individuals,they know that each time they have a child there is a _____ risk that child will be a carrier for the disorder.

Accepted Answer

The answer of Tony and Ling are both carriers of...

Question 7

Research by Plomin and colleagues indicated that the highest heritability correlation concerning the emotion of anger was found between

Accepted Answer

Identical twins raised together share both their genetics and environment, leading to the highest heritability correlation for traits like anger.

Question 8

Which is a common criticism of twin studies?

Accepted Answer

One of the most common criticisms of twin studies is the assumption that the environment has less of an influence on the similarity being studied in twins than genetics. This is often referred to as the "equal environments assumption," which assumes that environmental factors affecting the similarities and differences between twins are no different from those affecting siblings. This assumption is often criticized because twins may share more similar environments simply because they are twins and are treated more similarly by parents or society.

Question 9

An individual who is a carrier of a trait has

Accepted Answer

A carrier is an individual who has one dominant gene and one recessive gene for a trait, therefore option C describes a carrier. Option A describes an individual who expresses the trait, while option B describes an individual who does not express the trait. Option D describes an individual who does not carry the recessive gene and therefore does not have the potential to pass it on.

Question 10

Which type of study would be most likely to compare unrelated siblings living in the same household?

Accepted Answer

Adoption studies are designed to compare biological and environmental influences by examining the traits of adopted children in relation to their adoptive families and biological families. In this context, unrelated siblings living in the same household would most likely be part of an adoption study, as it allows researchers to observe the effects of the shared environment on individuals who do not share a genetic background.

Question 11

Your text reveals that if one identical twin is gay,there is almost a 50 percent chance that the other identical twin will also be gay.On the other hand,if a fraternal twin is schizophrenic,there is only about a 20 percent chance the other fraternal twin will be schizophrenic.The measure of likelihood that twins will share this mental illness in common is called a(n)

Accepted Answer

The measure of likelihood that twins will share a trait or disorder in common is called the concordance rate. The example given in the text shows a higher concordance rate for homosexuality among identical twins (around 50%), compared to the concordance rate of schizophrenia among fraternal twins (around 20%). Therefore, the best choice is A - concordance rate. The other options (B, C, and D) are not relevant to the context of the question or do not accurately reflect the measure of likelihood for twin studies.

Question 12

Heritability refers to

Accepted Answer

Heritability refers to the proportion of the differences in a trait among a group of people that is due to genetic differences. It does not refer to the genetic influence on a specific individual (A), nor does it refer to the percentage of pairs with the same trait (C) or the relationship between two traits (D).

Question 13

Which of the following is an accurate comparison of people with Down syndrome and people with Klinefelter syndrome?

Accepted Answer

People with Down syndrome have an extra copy of chromosome 21, which results in a total of 47 chromosomes in their cells. People with Klinefelter syndrome have an extra X chromosome, resulting in a total of 47 chromosomes as well. However, the extra chromosome in Klinefelter syndrome is a sex chromosome (X or Y), while in Down syndrome it is one of the other chromosomes (chromosome 21).

Question 14

Forty-year-old Chester has just begun to show symptoms indicating a deterioration of his nervous system.Chester most likely has

Accepted Answer

Huntington's disease is a degenerative disorder that affects the nervous system and usually begins to show symptoms in people in their forties or fifties. This matches Chester's symptoms. Klinefelter syndrome and Turner syndrome are genetic disorders that affect the sex chromosomes and usually present with symptoms related to reproductive or developmental issues rather than neurological symptoms. Cystic fibrosis is a genetic disorder affecting the lungs and digestive system and would not present with neurological symptoms.

Question 15

If shared environmental influences alone contribute to the expression of a trait,which of the following patterns of correlations would be observed?

Accepted Answer

Shared environmental influences imply that the environment plays a crucial role in the expression of a trait, regardless of genetic similarity. Therefore, both identical and fraternal twins would show a high correlation when raised together due to shared environmental factors. However, if raised apart, these influences would not be present, leading to no correlation.

Question 16

Which one of the following sets of data would show a strong genetic influence on the development of a trait?

Accepted Answer

Identical twins share 100% of their genes, so if they score more similarly on a trait despite being raised in different environments, it strongly suggests that genetics play a significant role in the development of that trait.

Question 17

The logic behind adoption studies is that

Accepted Answer

Adoption studies are used to help disentangle the effects of environment from genetics. If adopted children resemble their adoptive parents in certain traits, it suggests that these traits are influenced by the environment in which they are raised, rather than by genetic inheritance.

Question 18

When studying heritability in humans,an ethical behavior geneticist would be LEAST likely to

Accepted Answer

Conducting a selective breeding experiment in humans is highly unethical as it involves manipulating human reproduction and genetic makeup. This would violate ethical guidelines in research and is not acceptable in the scientific community. The other options, studying identical twins reared apart, comparing adopted children to biological parents, and investigating the relationship between behaviors of unrelated siblings are all methods that are commonly used in studying heritability in humans and are considered ethical.

Question 19

Jeff's mother died from Huntington's disease and he inherited the Huntington's gene.What is the likelihood he will also develop symptoms of Huntington's disease?

Accepted Answer

Huntington's disease is caused by a dominant gene, meaning if Jeff inherited the Huntington's gene from his mother, he will almost certainly develop the disease.

Question 20

_____ involves conducting DNA tests on the first cells after the mitosis of a fertilized egg.

Accepted Answer

Preimplantation genetic diagnosis involves conducting DNA tests on the first cells after the mitosis of a fertilized egg. Maternal blood sampling, Chorionic villus sampling, and Amniocentesis are all different methods of prenatal testing later in pregnancy.

Quiz 3: Genes,Environment,and Development