Question 1

Consider a trait determined by a rare, simple Mendelian, autosomal recessive allele. What is the concordance between identical twins? Between same-sex fraternal twins?

Accepted Answer

A)  identical concordance = 1; fraternal concordance = 0.071
B)  identical concordance = 1; fraternal concordance = 0.143
C)  identical concordance = 1; fraternal concordance = 0.250
D)  identical concordance = 1; fraternal concordance = 0.333
E)  identical concordance = 1; fraternal concordance = 0.500F) B) and D)
G) A) and B)

Question 2

If the value of the trait in 16% of the population is equal to 6 or greater, in what percentage of the population is the value of the trait greater than 4?

Accepted Answer

A)  8%
B)  16%
C)  32%
D)  68%
E)  84%F) C) and D)
G) A) and B)

Question 3

Which of the following traits would you expect to conform to a normal distribution?

Accepted Answer

A)  hypertension (high blood pressure) 
B)  type II diabetes
C)  Alzheimer's disease
D)  albinism
E)  sickle-cell anemiaF) A) and B)
G) B) and E)

Question 4

Which of the graphs below would likely represent the distribution of a simple, single gene trait?

Accepted Answer

A)  graph A
B)  graph B
C)  graph C
D)  graph DE) C) and D)
F) B) and D)

Question 5

Which of the traits depicted here has the SMALLEST heritability?

Accepted Answer

A)  trait M
B)  trait H
C)  trait K
D)  trait LE) B) and C)
F) None of the above

Question 6

Studies have shown that 5%-10% of all breast cancers are related to mutations in BRCA1 and BRCA2. A logical conclusion from these data is that:

Accepted Answer

A)  most women with breast cancer have mutations in one or both of these genes.
B)  most women with breast cancer must have inherited the gene from their mother.
C)  at least some breast cancers are caused by the environment or by genes other than BRCA1 and BRCA2.
D)  not all mutations in BRCA1 and BRCA2 have been identified to account for the other 90%-95% of breast cancers.E) A) and B)
F) B) and C)

Question 7

Personalized medicine matches the treatment to the disease, not to the patient.

Accepted Answer

A) True 
 B)False

Question 8

Salt intake is associated with an increased likelihood of high blood pressure and is therefore a(n)  _____ of this common disorder.

Accepted Answer

A)  environmental risk factor
B)  genetic risk factor
C)  complex trait
D)  simple trait
E)  associative risk factorF) A) and B)
G) A) and C)

Question 9

Lindsay and Joy are twins that share the same genetic material and appear so similar that their teachers cannot tell them apart. Lindsay and Joy are _____ twins.

Accepted Answer

A)  identical
B)  fraternal
C)  dizygotic
D)  monozygotic
E)  identical and monozygotic.F) D) and E)
G) All of the above

Question 10

The plots shown here depict several possible outcomes of an experiment comparing the mean phenotype of a behavioral trait in two strains of mice in three environments. Strain 1 is represented by filled circles and Strain 2 is represented by open circles. Environment 1 (E1)  is deficient in stimulation for the behavior, environment 2 (E2)  has an average level of stimulation, and environment 3 (E3)  is enriched in stimulation. Which of the possible results indicates the absence of genotype-by-environment interaction? 1)  is deficient in stimulation for the behavior, environment 2 (E2)  has an average level of stimulation, and environment 3 (E3)  is enriched in stimulation. Which of the possible results indicates the absence of genotype-by-environment interaction?   A) result M B) result H C) result K D) result L E) None of the answer options is correct." class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)  result M
B)  result H
C)  result K
D)  result L
E)  None of the answer options is correct.F) A) and E)
G) C) and D)

Question 11

If the concordance rate for a given trait is 10% for both identical and fraternal twins, this means that:

Accepted Answer

A)  genes play a major role in the development of this trait, and the effect of environment in the appearance of this trait is negligible.
B)  genes play a (relatively) minor role in the development of this trait, whereas environment plays a major role in the appearance of this trait.
C)  genes and environment contribute equally to the development of this trait.
D)  based on this data, you can make no statements regarding the role of either genes or environment in the manifestation of this trait.E) A) and D)
F) None of the above

Question 12

Diets high in fat and carbohydrates affect inbred lines of mice differently. One line becomes obese and the other does not. This is called a _____ interaction.

Accepted Answer

A)  genotype-by-environment
B)  phenotype-by-environment
C)  genotype-by-phenotype
D)  genotype-by-trait
E)  phenotype-by-genotypeF) All of the above
G) C) and D)

Question 13

When differences in the phenotype due to the environment can be ignored:

Accepted Answer

A)  the environmental component of a complex trait can be more easily identified.
B)  the genetic variation underlying phenotypic differences can be more easily identified.
C)  the trait is not considered a complex trait.
D)  epistatic interactions determine phenotypes.
E)  All of these choices are correct.F) C) and E)
G) A) and C)

Question 14

The scatterplots show the relation between the average phenotype of parents (x-axis)  and that of their offspring (y-axis)  for two traits in a variety of tropical sweet corn. One trait is ear height, which has a heritability of 75%; and the other is ear length, which has a heritability of 25%. To make the axes comparable, for each trait the phenotypic measurement is expressed as a deviation from the overall mean in multiples of the standard deviation. Which of the following matchups is CORRECT?

Accepted Answer

A)  Ear length is trait K and ear height is trait Q.
B)  Ear length is trait Q and ear height is trait K.
C)  Ear length and ear height are both trait K.
D)  Ear length and ear height are both trait Q.E) B) and C)
F) C) and D)

Question 15

In which of the complex traits shown here is variation determined almost completely by heredity?

Accepted Answer

A)  trait M
B)  trait H
C)  trait K
D)  trait L
E)  trait QF) All of the above
G) A) and C)

Question 16

Which of the traits depicted here illustrates regression toward the mean?

Accepted Answer

A)  trait M
B)  trait H
C)  trait K
D)  trait L
E)  trait QF) All of the above
G) None of the above

Question 17

Red coloration in wheat seeds is a complex trait influenced by three unlinked genes, each with two different alleles A and a; B and b; C and c. This Punnett square shows the results of a mating between two plants that are both heterozygous at all three loci.  The intensity of the red color phenotype is influenced by only one of the gene products.

Accepted Answer

A) True 
 B)False

Question 18

The scatterplots below show the relation between the average phenotype of parents (x-axis)  and that of their offspring (y-axis)  for three traits. One trait has a heritability of 90% (comparable to that of fingerprint ridge count) , another has a heritability of 50% (comparable to that of human height) , and yet another has a heritability of 25% (comparable to that of human longevity) . To make the axes comparable, for each trait the phenotypic measurement is expressed as a deviation from the overall mean in multiples of the standard deviation.
  The fact that all of the lines slope upward means that:

Accepted Answer

A)  variation in each trait is affected by differences in heredity.
B)  variation in each trait is affected by environmental differences.
C)  the genes affecting any one trait have no effect on any other trait.
D)  some genes affect all three traits.
E)  the traits all show genotype-by-environment interaction.F) B) and C)
G) A) and B)

Question 19

Which of the following are complex traits?

Accepted Answer

A)  type II diabetes
B)  red-green color blindness
C)  hemophilia
D)  obesity
E)  sickle-cell anemiaF) C) and D)
G) A) and E)

Question 20

Personalized medicine matches the treatment to the:

Accepted Answer

A)  insurance.
B)  hospital.
C)  disease.
D)  phenotype.
E)  genotype.F) C) and D)
G) B) and D)

Exam 18: The Genetic and Environmental Basis of Complex Traits

If the value of the trait in 16% of the population is equal to 6 or greater, in what percentage of the population is the value of the trait greater than 4?

Correct Answer
verified

Studies have shown that 5%-10% of all breast cancers are related to mutations in BRCA1 and BRCA2. A logical conclusion from these data is that:

Correct Answer
verified

Consider a trait determined by a rare, simple Mendelian, autosomal recessive allele. What is the concordance between identical twins? Between same-sex fraternal twins?

Correct Answer
verified

Correct Answer
verified

Which of the traits depicted here has the SMALLEST heritability?

Correct Answer
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Correct Answer
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Diets high in fat and carbohydrates affect inbred lines of mice differently. One line becomes obese and the other does not. This is called a _____ interaction.

Correct Answer
verified

Salt intake is associated with an increased likelihood of high blood pressure and is therefore a(n) _____ of this common disorder.

Correct Answer
verified

Which of the following traits would you expect to conform to a normal distribution?

Correct Answer
verified

If the concordance rate for a given trait is 10% for both identical and fraternal twins, this means that:

Correct Answer
verified

Personalized medicine matches the treatment to the disease, not to the patient.

Correct Answer
verified

In which of the complex traits shown here is variation determined almost completely by heredity?

Correct Answer
verified

Personalized medicine matches the treatment to the:

Correct Answer
verified

Correct Answer
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Correct Answer
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Which of the traits depicted here illustrates regression toward the mean?

Correct Answer
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Which of the following are complex traits?

Correct Answer
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Lindsay and Joy are twins that share the same genetic material and appear so similar that their teachers cannot tell them apart. Lindsay and Joy are _____ twins.

Correct Answer
verified

When differences in the phenotype due to the environment can be ignored:

Correct Answer
verified

Which of the graphs below would likely represent the distribution of a simple, single gene trait?

Correct Answer
verified

Exam 18: The Genetic and Environmental Basis of Complex Traits

If the value of the trait in 16% of the population is equal to 6 or greater, in what percentage of the population is the value of the trait greater than 4?

Correct AnswerverifiedShow Answer

Studies have shown that 5%-10% of all breast cancers are related to mutations in BRCA1 and BRCA2. A logical conclusion from these data is that:

Correct AnswerverifiedShow Answer

Consider a trait determined by a rare, simple Mendelian, autosomal recessive allele. What is the concordance between identical twins? Between same-sex fraternal twins?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Which of the traits depicted here has the SMALLEST heritability?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Diets high in fat and carbohydrates affect inbred lines of mice differently. One line becomes obese and the other does not. This is called a _____ interaction.

Correct AnswerverifiedShow Answer

Salt intake is associated with an increased likelihood of high blood pressure and is therefore a(n) _____ of this common disorder.

Correct AnswerverifiedShow Answer

Which of the following traits would you expect to conform to a normal distribution?

Correct AnswerverifiedShow Answer

If the concordance rate for a given trait is 10% for both identical and fraternal twins, this means that:

Correct AnswerverifiedShow Answer

Personalized medicine matches the treatment to the disease, not to the patient.

Correct AnswerverifiedShow Answer

In which of the complex traits shown here is variation determined almost completely by heredity?

Correct AnswerverifiedShow Answer

Personalized medicine matches the treatment to the:

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Which of the traits depicted here illustrates regression toward the mean?

Correct AnswerverifiedShow Answer

Which of the following are complex traits?

Correct AnswerverifiedShow Answer

Lindsay and Joy are twins that share the same genetic material and appear so similar that their teachers cannot tell them apart. Lindsay and Joy are _____ twins.

Correct AnswerverifiedShow Answer

When differences in the phenotype due to the environment can be ignored:

Correct AnswerverifiedShow Answer

Which of the graphs below would likely represent the distribution of a simple, single gene trait?

Correct AnswerverifiedShow Answer

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