Question 1

What must be true regarding the strains of organisms used to construct a QTL map?

Accepted Answer

A)  They must differ for the quantitative trait 
B)  They must differ for the molecular markers 
C)  Both of the above must be true 
A)  They must differ for the quantitative trait 
B)  They must differ for the molecular markers 
C)  Both of the above must be true C

Question 2

Inbreeding reduces which of the following variances to near zero?

Accepted Answer

A)  Genetic variance 
B)  Environmental variance 
C)  Both variances 
D)  Neither variance 
A)  Genetic variance 
B)  Environmental variance 
C)  Both variances 
D)  Neither variance A

Question 3

Heritability may be calculated as which of the following?

Accepted Answer

A)  The total variance minus environmental variance 
B)  Total variance minus genetic variance 
C)  Genetic variance divided by environmental variance 
D)  Genetic variance divided by total variance 
E)  None of the answers are correct 
A)  The total variance minus environmental variance 
B)  Total variance minus genetic variance 
C)  Genetic variance divided by environmental variance 
D)  Genetic variance divided by total variance 
E)  None of the answers are correct D

Question 4

Before conducting a regression analysis, it is first necessary to show that two variables have a cause-
effect relationship using a correlation coefficient calculation.

Accepted Answer

A) True 
 B)False

Question 5

The process of mating between genetically unrelated individuals is called inbreeding.

Accepted Answer

A) True 
 B)False

Question 6

Since quantitative traits are frequently associated with a number of genes and the environment, it is
difficult to assign accurate phenotypic classes for a Punnett square diagram.

Accepted Answer

A) True 
 B)False

Question 7

Many organisms used in modern agriculture are a result of artificial selection.

Accepted Answer

A) True 
 B)False

Question 8

In calculations of the degrees of freedom for a correlation coefficient, what value does the degrees of freedom take?

Accepted Answer

A)  (n - 1) 
B)  (n - 2) 
C)  (n - 1)/2 
D)  2(n - 1) 
A)  (n - 1) 
B)  (n - 2) 
C)  (n - 1)/2 
D)  2(n - 1)

Question 9

When analyzing two variables, the strength of the association between the variables is called the .

Accepted Answer

A)  Covariance 
B)  Standard deviation 
C)  Correlation coefficient 
D)  Variance 
A)  Covariance 
B)  Standard deviation 
C)  Correlation coefficient 
D)  Variance

Question 10

The amount of phenotypic variation in a group that is due to genetic variation is called heritability.

Accepted Answer

A) True 
 B)False

Question 11

After calculating a correlation coefficient you discover that the value is not significant at the 5% level. What can be done to produce a significant difference?

Accepted Answer

A)  Increase the sample size 
B)  Decrease the sample size 
C)  Nothing, the value will remain the same regardless of sample size 
A)  Increase the sample size 
B)  Decrease the sample size 
C)  Nothing, the value will remain the same regardless of sample size

Question 12

What must be true for a correlation coefficient to be calculated between two traits?

Accepted Answer

A)  The values for the traits must have been obtained from unbiased sampling 
B)  The relationship between the two traits must be linear 
C)  The traits must follow a normal distribution 
D)  All of the answers are correct 
A)  The values for the traits must have been obtained from unbiased sampling 
B)  The relationship between the two traits must be linear 
C)  The traits must follow a normal distribution 
D)  All of the answers are correct

Question 13

QTL mapping determines the relationship between genes for quantitative traits and which of the following?

Accepted Answer

A)  The centromere 
B)  Transposon sites 
C)  Structural genes 
D)  Molecular markers such as RFLPs 
A)  The centromere 
B)  Transposon sites 
C)  Structural genes 
D)  Molecular markers such as RFLPs

Question 14

Which of the following steps is NOT used in conducting a backcross in order to map a QTL?

Accepted Answer

A)  Two inbred strains that differ in a quantitative trait are crossed. 
B)  The F1 offspring are crossed with each other. 
C)  The F2 offspring contain different combinations of the parental chromosomes. 
D)  By using genetic markers, it is determined which parent each chromosome came from and thus isolate the genes. 
A)  Two inbred strains that differ in a quantitative trait are crossed. 
B)  The F1 offspring are crossed with each other. 
C)  The F2 offspring contain different combinations of the parental chromosomes. 
D)  By using genetic markers, it is determined which parent each chromosome came from and thus isolate the genes.

Question 15

Which of the following best describes the degrees of freedom for the calculation of variance?

Accepted Answer

A)  (n + 1) 
B)  2(n + 1) 
C)  (n - 1)/n 
D)  (n - 1) 
A)  (n + 1) 
B)  2(n + 1) 
C)  (n - 1)/n 
D)  (n - 1)

Question 16

Which of the following is incorrect concerning quantitative traits?

Accepted Answer

A)  Individuals fall into distinct classes for comparison 
B)  The phenotypic variation for the trait is continuous 
C)  The frequency distribution follows a bell-shaped curve 
D)  All of the answers are correct 
A)  Individuals fall into distinct classes for comparison 
B)  The phenotypic variation for the trait is continuous 
C)  The frequency distribution follows a bell-shaped curve 
D)  All of the answers are correct

Question 17

Heritability is the amount of genetic variation in a particular population and a particular
environment.

Accepted Answer

A) True 
 B)False

Question 18

Realized heritability may be determined from artificial selection experiments.

Accepted Answer

A) True 
 B)False

Question 19

A heritability value of 0.997 indicates which of the following?

Accepted Answer

A)  The majority of the phenotypic variation has a genetic basis 
B)  The majority of the phenotypic variation has an environmental basis 
C)  The trait is polygenic 
D)  There is a significant difference between the two strains 
E)  None of the answers are correct 
A)  The majority of the phenotypic variation has a genetic basis 
B)  The majority of the phenotypic variation has an environmental basis 
C)  The trait is polygenic 
D)  There is a significant difference between the two strains 
E)  None of the answers are correct

Question 20

For a quantitative trait, the total variance of the population is due to which of the following?

Accepted Answer

A)  The amount of variance due to genetic factors only 
B)  The amount of variance due to environmental factors only 
C)  The difference between the variance attributed to genetic and environmental factors 
D)  The sum of the genetic and environmental variances 
A)  The amount of variance due to genetic factors only 
B)  The amount of variance due to environmental factors only 
C)  The difference between the variance attributed to genetic and environmental factors 
D)  The sum of the genetic and environmental variances

Exam 25: Quantitative Genetics

What must be true regarding the strains of organisms used to construct a QTL map?

Inbreeding reduces which of the following variances to near zero?

Heritability may be calculated as which of the following?

Before conducting a regression analysis, it is first necessary to show that two variables have a cause- effect relationship using a correlation coefficient calculation.

The process of mating between genetically unrelated individuals is called inbreeding.

Since quantitative traits are frequently associated with a number of genes and the environment, it is difficult to assign accurate phenotypic classes for a Punnett square diagram.

Many organisms used in modern agriculture are a result of artificial selection.

In calculations of the degrees of freedom for a correlation coefficient, what value does the degrees of freedom take?

When analyzing two variables, the strength of the association between the variables is called the .

The amount of phenotypic variation in a group that is due to genetic variation is called heritability.

After calculating a correlation coefficient you discover that the value is not significant at the 5% level. What can be done to produce a significant difference?

What must be true for a correlation coefficient to be calculated between two traits?

QTL mapping determines the relationship between genes for quantitative traits and which of the following?

Which of the following steps is NOT used in conducting a backcross in order to map a QTL?

Which of the following best describes the degrees of freedom for the calculation of variance?

Which of the following is incorrect concerning quantitative traits?

Heritability is the amount of genetic variation in a particular population and a particular environment.

Realized heritability may be determined from artificial selection experiments.

A heritability value of 0.997 indicates which of the following?

For a quantitative trait, the total variance of the population is due to which of the following?

Overview of Genetics

Mendelian Inheritance

Reproduction and Chromosome Transmission

Extensions of Mendelian Inheritance

Non-Mendelian Inheritance

Genetic Linkage and Mapping in Eukaryotes

Genetic Transfer and Mapping in Bacteria and

Variation in Chromosome Structure and Number

Molecular Structure of Dna and Rna

Chromosome Organization and Molecular Structure

Dna Replication

Gene Transcription and Rna Modification

Translation of Mrna

Gene Regulation in Bacteria and Bacteriophages

Gene Regulation in Eukaryotes

Gene Mutation and Dna Repair

Recombination and Transposition at the Molecular

Recombinant Dna Technology

Biotechnology

Genomics I: Analysis of Dna

Genomics II: Functional Genomics, Proteomics, and

Medical Genetics and Cancer

Developmental Genetics

Population Genetics

Evolutionary Genetics

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