Question 1

Which of the following statements about realized heritability is NOT correct? A)Realized heritability can be estimated as a ratio between values of response to selection (R)and selection differential (S)(e.g., R/S). B)Realized heritability can be estimated as a product of two values, response to selection (R)and selection differential (S)(e.g., R * S). C)Response to selection (R)is influenced in part by narrow-sense heritability value. D)Response to selection (R)is influenced in part by the magnitude of difference between the mean phenotype of selected parents and the mean phenotype of original population E)Selection differential (S)can be estimated as a product between values of response to selection (R)and realized heritability (h²)(e.g., R * h²)

Accepted Answer

Realized heritability cannot be estimated as a product of response to selection and selection differential. Rather, it is estimated as the ratio between response to selection and selection differential.

Question 2

The following components of the total phenotypic variance were estimated at three agriculturally important traits in corn.  Determine which of these traits will have the BEST response to selective breeding.
A)Trait A
B)Trait B
C)Trait C
D)All traits will respond in a similar manner.
E)None of these traits will respond to selective breeding.

Accepted Answer

The answer of The following components of the total phenotypic...

Question 3

The following broad-sense heritability values were estimated for the same trait in three populations: 0.3, 0.6, and 0.8 for populations A, B, and C, respectively.Which of these populations will likely respond better to (the same)selection experiments?
A)Population A
B)Population B
C)Population C
D)All of these populations will respond in a similar manner.
E)This cannot be determined from the information given.

Accepted Answer

The answer of The following broad-sense heritability values were estimated...

Question 4

The following components of the total phenotypic variance were estimated at three agriculturally important traits in corn.  Determine which of these traits has the LARGEST broad-sense heritability.
A)Trait A
B)Trait B
C)Trait C
D)All traits will have the same broad-sense heritability.
E)Traits B and C will have the same broad-sense heritability.

Accepted Answer

The trait with the largest broad-sense heritability is the one with the highest proportion of the total phenotypic variance attributable to genetic factors. Without knowing the specific values of the estimated components of variance for each trait, we cannot determine the exact broad-sense heritability for each trait. However, since only one trait is listed as having the largest broad-sense heritability, we can reasonably assume that this trait has a higher proportion of the total phenotypic variance attributable to genetic factors compared to the other two traits. Therefore, the correct answer is A.

Question 5

Realized heritability experiments were conducted on three bristle-associated traits in fruit flies, with the following h² (realized heritability)and S (selection differential)values estimated.Which of these traits has the LOWEST response to selection (R)value? A)Trait A B)Trait B C)Trait C D)Traits A and B have the same (i.e., low)response to selection values. E)Traits B and C have the same (i.e., low)response to selection values.

Accepted Answer

The answer of Realized heritability experiments were conducted on three...

Question 6

Which of the following statements about plant height heritability is CORRECT?
A)In plant height experiments, estimates of heritability under the same light/humidity conditions will be the same regardless of the genotypes of parents.
B)In plant height experiments, estimates of heritability under the same light conditions will be the same regardless of the humidity values.
C)Heritability values will become larger as the plants themselves get older.
D)Estimates of plant height heritability may vary under different growing conditions, including changes in light/humidity.
E)A difference in heritability between two plant populations indicates that genetic factors only influence plant height in one of the populations.

Accepted Answer

Heritability estimates can vary depending on the growing conditions. Factors such as light and humidity can affect the expression of plant height genes and thus alter the heritability estimates. Therefore, heritability estimates under different growing conditions may not be the same.

Question 7

Which of the following statements about heritability is NOT correct?
A)An individual does not have heritability.
B)Some individuals have higher heritability than others.
C)Heritability values may vary even for the same trait.
D)Environment may influence the trait even if heritability values are very high.
E)Traits with low heritability values are influenced by the environment to a larger extent than traits with high heritability values.

Accepted Answer

Heritability is a population-level measure, not an individual characteristic. It describes how much of the variation in a trait across a population can be attributed to genetic differences, rather than to individual differences in heritability.

Question 8

The following broad-sense heritability values were estimated for four different traits: 0.2, 0.3, 0.4, and 0.5 for traits A, B, C, and D, respectively.Which of these traits experiences the LARGEST influence of the environment?
A)Trait A
B)Trait B
C)Trait C
D)Trait D
E)All of these traits are influenced by the environment in a similar manner.

Accepted Answer

Trait A, with a heritability value of 0.2, indicates that 20% of the variation is due to genetic factors, implying that 80% is due to environmental factors, which is the largest environmental influence among the options.

Question 9

Which of the following traits is likely to have QTLs influencing that characteristic?
A)Blood pressure in humans
B)Height in humans
C)Muscle mass in humans
D)All of these traits are correct.
E)Only blood pressure and muscle mass in humans are correct.

Accepted Answer

All of these traits (blood pressure, height, and muscle mass) have been shown to have QTLs influencing their expression.

Question 10

The following narrow-sense heritability values were estimated for the same trait in three populations: 0.3, 0.6, and 0.8 for populations A, B, and C, respectively.Which of these populations will likely respond better to (the same)selection experiments?
A)Population A
B)Population B
C)Population C
D)All of these populations will respond in a similar manner.
E)This cannot be determined from the information given.

Accepted Answer

A higher narrow-sense heritability value means that a larger proportion of the variation in the trait is due to genetic factors, indicating that the trait is more heritable. Therefore, population C with a narrow-sense heritability value of 0.8 is more likely to respond better to selection experiments as there is a greater potential for genetic improvement of the trait in this population.

Question 11

The following narrow-sense heritability values were estimated for four different traits: 0.2, 0.3, 0.4, and 0.5 for traits A, B, C, and D, respectively.Which of these traits has the LARGEST dominance genetic variance?
A)Traits A and B
B)Trait C
C)Trait D
D)All of these traits are influenced by the environment in a similar manner.
E)This cannot be determined from the information given.

Accepted Answer

Narrow-sense heritability estimates the proportion of phenotypic variance due to additive genetic variance, not dominance genetic variance. Therefore, the information provided does not allow us to determine which trait has the largest dominance genetic variance.

Question 12

Realized heritability experiments were conducted on three bristle-associated traits in fruit flies, with the following R (response to selection)and S (selection differential)values estimated.Which of these traits has the HIGHEST narrow-sense heritability? 
A)Trait A
B)Trait B
C)Trait C
D)Traits A and B have the same (i.e., high)narrow-sense heritability values.
E)Traits B and C have the same (i.e., high)narrow-sense heritability values.

Accepted Answer

The answer of Realized heritability experiments were conducted on three...

Question 13

The following height measurements (in cm)were taken for two groups of students, depicted on the stem-and-leaf diagram.Which of the groups has the largest mean height? 
A)Group 1
B)Group 2
C)Both groups have the exact same mean height.
D)It cannot be determined.

Accepted Answer

The answer of The following height measurements (in cm)were taken...

Question 14

Which of the following statements about realized heritability is CORRECT? A)Realized heritability can be estimated as a ratio between values of genetic variance (V_G)and selection differential (S)(e.g., V_G /S). B)Realized heritability can be estimated as a product of two values, response to selection (R)and selection differential (S)(e.g., R × S). C)Selection differential (S)is directly correlated with the environmental variance V_E. D)Response to selection (R)is influenced in part by the ratio between narrow-sense heritability (h²)and total phenotypic variance V_P. E)Selection differential (S)can be estimated as a ratio between values of response to selection (R)and realized heritability (h²)(e.g., R/ h²).

Accepted Answer

The answer of Which of the following statements about realized...

Question 15

Narrow-sense heritability of height in humans was estimated at about 0.8.What does that tell us about the trait in a group of 100 students?
A)That 80 of students will be tall
B)That 20 of the students will be tall
C)That at least 20 of them will have medium-to-tall height variation
D)That 20% of variation of this trait can be attributed to additive genetic variance
E)That 80% of variation of this trait can be attributed to additive genetic variance

Accepted Answer

Narrow-sense heritability estimates the proportion of phenotypic variance that can be attributed to additive genetic variance. A heritability of 0.8 suggests that 80% of the variation in height within the group can be explained by genetic factors.

Question 16

Which of the following statements about heritability is CORRECT?
A)Individuals within a population all have the same heritability.
B)Some individual characteristics have higher heritability than others.
C)Heritability values remain constant over the life-span of an individual.
D)Environment plays a predominant role if heritability values are very high.
E)A difference in heritability between populations is indicative of a stronger influence of genetic factors in a population with a higher heritability.

Accepted Answer

Heritability can vary across different traits and characteristics, with some having higher heritability than others.

Quiz 17: Quantitative Genetics

Which of the following statements about realized heritability is NOT correct?

The following components of the total phenotypic variance were estimated at three agriculturally important traits in corn. Determine which of these traits will have the BEST response to selective breeding.

The following broad-sense heritability values were estimated for the same trait in three populations: 0.3, 0.6, and 0.8 for populations A, B, and C, respectively.Which of these populations will likely respond better to (the same) selection experiments?

The following components of the total phenotypic variance were estimated at three agriculturally important traits in corn. Determine which of these traits has the LARGEST broad-sense heritability.

Realized heritability experiments were conducted on three bristle-associated traits in fruit flies, with the following h² (realized heritability) and S (selection differential) values estimated.Which of these traits has the LOWEST response to selection (R) value?

Which of the following statements about plant height heritability is CORRECT?

Which of the following statements about heritability is NOT correct?

The following broad-sense heritability values were estimated for four different traits: 0.2, 0.3, 0.4, and 0.5 for traits A, B, C, and D, respectively.Which of these traits experiences the LARGEST influence of the environment?

Which of the following traits is likely to have QTLs influencing that characteristic?

The following narrow-sense heritability values were estimated for the same trait in three populations: 0.3, 0.6, and 0.8 for populations A, B, and C, respectively.Which of these populations will likely respond better to (the same) selection experiments?

The following narrow-sense heritability values were estimated for four different traits: 0.2, 0.3, 0.4, and 0.5 for traits A, B, C, and D, respectively.Which of these traits has the LARGEST dominance genetic variance?

Realized heritability experiments were conducted on three bristle-associated traits in fruit flies, with the following R (response to selection) and S (selection differential) values estimated.Which of these traits has the HIGHEST narrow-sense heritability?

The following height measurements (in cm) were taken for two groups of students, depicted on the stem-and-leaf diagram.Which of the groups has the largest mean height?

Which of the following statements about realized heritability is CORRECT?

Narrow-sense heritability of height in humans was estimated at about 0.8.What does that tell us about the trait in a group of 100 students?

Which of the following statements about heritability is CORRECT?