Deck 22: Inheritance Of Complex Traits

Question 1

Traits in which phenotypic variation can be measured in a sample of individuals from the population are known as

A) qualitative traits.
B) quantitative traits.
C) unique traits.
D) statistical traits.
E) standard traits.

Answer 1

B

Question 2

Which of the following statistics is useful for describing quantitative traits?

A) Correlation coefficient
B) Frequency distribution
C) Mode of the frequency distribution
D) Mean
E) All of these

Answer 2

E

Question 3

The evidence that threshold traits in humans have a genetic basis has come from the study of

A) non-related individuals.
B) marriage partners.
C) parents and children.
D) twins.
E) None of these

Answer 3

D

Question 4

Which of the following is the formula for variance?

A) S[(X? - X)(Y? - Y)]/(n-1)S?S?
B) S[(X? - X)(Y? - Y)]/(n-1)
C) S(X? - X)²/(n-1)
D) SX?/n
E) None of these

Question 5

Which of the following is not true of threshold traits?

A) Expression is significantly affected by environment
B) Genetic liability must cross a critical value for expression to occur
C) Monozygotic twins much more likely to both express such traits
D) Nature of genetic factors involved are poorly understood
E) They often show continuous variation in phenotype.

Question 6

Which of the following is not a feature of quantitative traits?

A) Environment influences phenotype
B) Effect of environment can vary with genotype
C) Mendel's laws do not apply to these traits
D) Two or more genes are often involved
E) All of these

Question 7

Similarity with respect to a threshold trait is assessed by determining the

A) liability rate.
B) threshold rate.
C) concordance rate.
D) zygomatic rate.
E) standard deviation.

Question 8

Underlying risk factors that contribute to a variable are called

A) the liability.
B) the risk.
C) the threshold.
D) the quantity.
E) None of these

Question 9

Which organism was studied by Herman Nilsson-Ehle,in his analysis of multiple genetic contributions to trait variability?

A) Broad bean
B) Wheat grains
C) E. coli
D) Garden peas
E) Drosophila f) Tobacco

Question 10

How can the number of genes influencing a trait be estimated?

A) Phenotypic segregation
B) DNA hybridization
C) Northern blotting
D) Allelism
E) Ames Test

Question 11

A statistic that gives the "center" or average of a distribution is known as the

A) mean.
B) mode.
C) deviation.
D) frequency.
E) X2 value.

Question 12

A trait that appears when the liability exceeds a certain level is known as a(n)

A) liability trait.
B) quantitative trait.
C) threshold trait.
D) qualitative trait.
E) phenotypic trait.

Question 13

Which of the following is an example of a complex trait?

A) Body size
B) Height
C) Weight
D) All of these
E) None of these

Question 14

Which of the following could be regarded as a threshold trait?

A) Cleft lip
B) Schizophrenia
C) Bipolar disorder
D) Cleft lip and Schizophrenia
E) All of these

Question 15

The genetic basis of complex traits is demonstrated by:
1)Resemblance between relatives
2)Similar appearance of monozygotic twins
3)Responses to selective breeding such as the increase in resistance to disease

A) 1
B) 2
C) 3
D) 1 and 2
E) All of these

Question 16

In a sample,the class that contains the most observations is known as the

A) mean class.
B) modal class.
C) normal class.
D) hyper class.
E) None of these

Question 17

The hallmark of quantitative traits is that

A) Mendel's laws do not apply to these traits.
B) the environment does not influence phenotype.
C) there is never more than one gene involved.
D) they vary continuously in a population of individuals.
E) All of these

Question 18

Who was one of the first people to show that variation in a quantitative trait is due to a combination of genetic and environmental factors?

A) Wilhelm Johannsen
B) James Watson
C) Francis Crick
D) Edward East
E) Joshua Lederberg

Question 19

The small fraction of all the individuals in the population that can be measured is known as the

A) group.
B) sample.
C) population.
D) set.
E) None of these

Question 20

What type of evidence suggests the genetic basis of traits like cleft lip?

A) Concordance for monozygotic twins is much greater than for dizygotic twins.
B) Environment significantly affects such traits.
C) Genes predispose individuals to express the trait.
D) Risk increases as genetic relationships become more distant.
E) Some kind of threshold must be reached before trait can be expressed.

Question 21

Populations with a small standard deviation for a particular quantitative trait are

A) usually prone to extinction.
B) usually more homozygous for that trait.
C) usually more heterozygous for that trait.
D) not very common.
E) always normally distributed.

Question 22

Quantitative traits are controlled by many different factors in the environment and in the genotype.This is the ___________ hypothesis.

A) Multiple Factor Hypothesis
B) Polygenic Factor Hypothesis
C) Pleiotropic Factor Hypothesis
D) Dominant Factor Hypothesis
E) Majority Factor Hypothesis

Question 23

The difference between the mean of the selected parents and the mean of the population from which they were selected is known as

A) selection quotient.
B) selection differential.
C) selection additive.
D) selection quotient and selection differential.
E) All of these

Question 24

The proportion of heritability that is due to shared environmental factors is known as

A) rearing coefficient
B) environmentality
C) environment coefficient
D) rearing coefficient and environment coefficient
E) All of these

Question 25

Knowledge of heritability is important for

A) developing conservation strategies for natural populations.
B) developing goal oriented selective breeding programs.
C) developing health care programs (for high blood pressure, etc.).
D) understanding how natural populations evolve.
E) All of these

Question 26

The correlation between monozygotic twins reared apart provides an estimate of

A) narrow sense heritability.
B) narrow sense correlation.
C) broad sense heritability.
D) broad sense correlation.
E) None of these

Question 27

Which of the following is a component of the total variability of a trait?

A) Additive effects of alleles
B) Dominance interactions among alleles
C) Environmental effects
D) Epistatic relationships among alleles
E) All of these

Question 28

Which of the following has been instrumental in discovering genetic links to human multifactorial diseases?

A) Crossing studies
B) Estimating narrow sense heritability
C) QTL mapping
D) Selection studies
E) Studies in different environments

Question 29

Which of the following is a component of narrow sense heritability?

A) Additive effects of alleles
B) Dominance interactions among alleles
C) Environmental effects
D) Epistatic relationships among alleles
E) All of these

Question 30

The correlation between dizygotic twins reared apart provides a maximum estimate of

A) narrow sense heritability.
B) narrow sense correlation.
C) broad sense heritability.
D) broad sense correlation.
E) None of these

Question 31

Which of the following is not a component of broad sense heritability?

A) Additive effects of alleles
B) Dominance interactions among alleles
C) Environmental effects
D) Epistatic relationships among alleles
E) All of these

Question 32

Which statistic quantitatively summarizes a pattern of resemblance?

A) Regression analysis
B) Correlation coefficient
C) Standard deviation
D) Mean
E) Mode

Question 33

When the correlation coefficient is zero

A) the measurements are uncorrelated.
B) the measurements are weakly correlated.
C) the measurements are moderately correlated.
D) the measurements are highly correlated.
E) None of these

Question 34

Standard deviation can be more useful than variance in describing a quantitative trait because it

A) is always positive.
B) is a more accurate measure.
C) is the square of the variance.
D) has the same units of measure as the mean.
E) has useful mathematical properties.

Question 35

If the broad sense heritability is close to 0 for a population then

A) much of the observed variability in the population is due to genetic differences.
B) much of the observed variability in the population is due to heritable traits.
C) little of the observed variability is due to genetic differences.
D) little of the observed variability is due to environmental factors.
E) None of these

Question 36

A trait that is controlled by many genes is referred to as

A) pleiotrophic.
B) polygenic.
C) multigenic.
D) dominant.
E) codominant.

Question 37

The additive genetic variance,V?,,as a fraction of the total phenotypic variance,is called the

A) total phenotypic variance.
B) broad sense heritability.
C) narrow sense heritability.
D) broad sense inheritance.
E) narrow sense inheritance.

Question 38

The proportion of the total phenotypic variance that is due to genetic differences among individuals in a population is known as

A) narrow sense heritability.
B) broad sense heritability.
C) heritability.
D) broad sense inheritance.
E) narrow sense inheritance.

Question 39

Which of the following statistics indicates the extent to which data are scattered around the mean in a frequency distribution?

A) Mode
B) Variance
C) Standard deviation
D) Mode and Variance
E) Variance and Standard deviation

Question 40

What is the total phenotypic variance for a wheat population if the environmental variance is 12.3 days² and the genetic variance is 3.7 days²?

A) 12.3 days²
B) 3.7 days²
C) 16.0 days²
D) 45.5 days²
E) 8.6 days²

Question 41

IQ had a high heritability in twin studies

A) however, environmental effects were negligible.
B) however, we cannot assume differences among human population are genetic.
C) therefore, differences among human populations must be genetic.
D) therefore, intelligence is highly dependent on genotype.
E) therefore, environment has little affect on intelligence.

Question 42

The most thorough genetic analysis of personality in the general population has come from

A) Minnesota Study of Dizygotic Twins Raised Together.
B) Minnesota Study of Monozygotic Twins Raised Together.
C) Minnesota Study of Monozygotic Twins Raised Apart.
D) Minnesota Study of Dizogotic Twins Raised Apart.
E) Minnesota Study of Non-Biological Children.

Question 43

How did Nilsson-Ehle and East provide evidence that the genetic component of this variation could involve the contributions of several different genes?

Question 44

On a class exam three students earned an A,twelve students earned a B,48 students earned a C,twelve students earned a D and four students earned an F.Draw the frequency distribution of this sample of students.

Question 45

Which of the following are indicators that genetic factors can influence human behavior?

A) Huntington's disease
B) Phenylketonuria
C) Down Syndrome
D) Huntington's disease and Phenylketonuria
E) All of these

Question 46

Determine the mode,mean,variance and standard deviation for the following data set.
3,5,6,6,8,1,12

Question 47

In a quantitative genetic analysis of personality traits among monozygotic twins,it was found that:
1)Genetic differences play a small role in determining personality traits.
2)Genetic differences play a significant role in determining personality traits.
3)The broad-sense heritability is reasonably high in the 0.34-0.5 range.

A) 1
B) 2
C) 3
D) 1 and 2
E) 2 and 3

Question 48

How do the studies between monozygotic twins show that there is a genetic component to intelligence?

Question 49

What fraction of the variation among IQ scores is attributable to genetic differences among people?

A) 0.1
B) 0.3
C) 0.5
D) 0.7
E) 0.9

Question 50

How does the correlation between monozygotic twins reared apart provides an estimate of the broad-sense heritability?