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74 terms

Mol Gen Module 5

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If mating occurs solely between relatives, eventually what will happen to the population?
It will be completely homozygous
Which of the following is a concern of population genetics?
How many people have color blindness in Utah
A gene or a trait is said to be polymorphic if
more that one form exists in the population
Inbreeding in populations that are normally outbreeding leads to which of the following?
More individuals affected by rare diseases
T or F, Overdominance refers to the lack of expression of recessive phenotypes.
False
T or F, A QTL is a gene
False
T or F, Inbreeding results in an increase in the frequency of heterozygotes compared to the results of random mating.
False
T or F, An allele is fixed if it has a frequency of 1
True
T or F, Standard deviation is calculated in the same units as the original measurements, while variance is calculated in units squared.
Ture
Match each term to the appropriate letter choice.
a. All genetic information within a Mendelian population
b. The mean trait value decreases from one generation to another
c. Any change in allele frequencies within a population
d. Probability of alleles being identical by descent
e. Alleles may disappear from the population simply by chance
f. Movement of genes
g. Generation of new alleles

negative directional selection
b
Rapid changes in allelic frequencies by __ take place in populations that are __.
a. mutation
b. evolving
c. inbred
d. small
e. genetic drift
e, d
Knowing the ___________ of a trait has great practical importance because it allows statistical predictions regarding the phenotypes of offspring to be made on the basis of the parent's _____________.
a. variance
b. inbreeding coefficient
c. phenotype
d. heritability
e. genotype
d, c
Migration tends to __genetic variation between subpopulations and __ genetic variation within each subpopulation.
a. increase
b. not change
c. reduce
d. standardize
e. invert
c, a
QTL mapping requires all of the following except:
Question options:

genetic markers.

offspring.

a genetic map.

a controlled cross.

an estimate of homozygosity in the population.
an estimate of homozygosity in the population
In a population in Hardy-Weinberg equilibrium, what will be the proportion of matings between homozygotes?
Question options:

p2 + 2pq

P4

p4 + q4

p4 + q4 + 2p2q2

4p2q2
p4 + q4 + 2p2q2
Which statement is true regarding heritability and continuous variation?
Question options:

Heritability measures the degree to which genes determine phenotype.

As the number of gene loci that affect a trait increases, the proportion of extreme version of the trait also increases.

The total variance used to calculate heritability measures all the variance in a population.

A heritability value of 0.8% of the total variance is due to differences in the environment.

A low heritability score means that genes are less influential than environment in determining phenotypic variation.
A low heitability score means the genes are less influential than environment in determining the phenotypic variation
Which of the following is NOT an example of nonrandom mating?
Question options:

positive assortative mating

inbreeding

outbreeding

panmixis

negative assortative mating
panmixis
Natural selection
differential reproduction of genotypes
T or F, Genetic differences in large, randomly breeding populations remain constant if migration occurs.
False
T or F, The heritablity of a trait is the proportion of genes affecting that trait
False, The heritability of a trait is the proportion of differences among individuals for a trait that is due to genetic variation.
Match each term to the appropriate letter choice.
a. All genetic information within a Mendelian population
b. The mean trait value decreases from one generation to another
c. Any change in allele frequencies within a population
d. Probability of alleles being identical by descent
e. Alleles may disappear from the population simply by chance
f. Movement of genes
g. Generation of new alleles

evolution
c
Match each term to the appropriate letter choice.
a. additive, dominance, genic interaction
b. distribution around the mean
c. phenotype proportions
d. pleiotropy
e. bell-shaped
f. regression coefficient
g. relationship between variables
h. correlation coefficient

varience
b
Match each term to the appropriate letter choice.
a. All genetic information within a Mendelian population
b. The mean trait value decreases from one generation to another
c. Any change in allele frequencies within a population
d. Probability of alleles being identical by descent
e. Alleles may disappear from the population simply by chance
f. Movement of genes
g. Generation of new alleles

gene pool
a
Match each term to the appropriate letter choice.
a. additive, dominance, genic interaction
b. distribution around the mean
c. phenotype proportions
d. pleiotropy
e. bell-shaped
f. regression coefficient
g. relationship between variables
h. correlation coefficient

frequency distribution
c
Which of the following statistical term is a not measure of central tendency?
Question options:

The Mean

The Mode

The Median

Correlation

All of the above
correlation
In a tropical human population in Hardy-Weinberg equilibrium for an autosomal locus determining presence/absence of pigment in the skin, the frequency of albinism (aa) is 1 in 10,000. The frequency of heterozygotes is approximately:
Question options:

1 in 50

1 in 100

1 in 1000

1 in 75

1 in 25
1 in 50
Human albinism is an autosomal recessive trait. Suppose that you find a village in the Andes where 1/4 of the population is albino. If the population size is 1000 and the population is in Hardy-Weinberg equilibrium with respect to this trait, how many individuals are expected to be heterozygotes?
Question options:

50

250

300

500

750
500
In a human population, the genotype frequencies at one locus are 0.5 AA, 0.4 Aa, and 0.1 aa. The frequency of the A allele is:
Question options:

0.20

0.32

0.50

0.70

0.90
0.70
Which of the following is NOT a feature of Darwin's theory of natural selection?
Question options:

A) A population adapts to its environment due to the variable reproductive success of individuals.

B) There is no heritable variation among individuals.

C) Individuals with poor fitness never produce offspring.

D) A and B

E) B and C
B and C
T or F, Genetic Variation must exist in a population before evolution can take place
True
T or F, A population may be in H-W equilibrium for one locus but not for others
True
T or F, Genetic drift arises from sampling errors and chance
True
Match each term to the appropriate letter choice.
a. All genetic information within a Mendelian population
b. The mean trait value decreases from one generation to another
c. Any change in allele frequencies within a population
d. Probability of alleles being identical by descent
e. Alleles may disappear from the population simply by chance
f. Movement of genes
g. Generation of new alleles

mutation
g
Match each term to the appropriate letter choice.
a. All genetic information within a Mendelian population
b. The mean trait value decreases from one generation to another
c. Any change in allele frequencies within a population
d. Probability of alleles being identical by descent
e. Alleles may disappear from the population simply by chance
f. Movement of genes
g. Generation of new alleles

mutation
e
Match each term to the appropriate letter choice.
a. additive, dominance, genic interaction
b. distribution around the mean
c. phenotype proportions
d. pleiotropy
e. bell-shaped
f. regression coefficient
g. relationship between variables
h. correlation coefficient

normal distribution
e
Match each term to the appropriate letter choice.
a. All genetic information within a Mendelian population
b. The mean trait value decreases from one generation to another
c. Any change in allele frequencies within a population
d. Probability of alleles being identical by descent
e. Alleles may disappear from the population simply by chance
f. Movement of genes
g. Generation of new alleles

interbreeding coefficient
d
Match the phenomenon to its effect on populations. There is only one best answer for each number. You may use letters more than once.
a. Allele frequencies become more similar across populations.
b. Generation of new alleles changes allele frequencies very slowly.
c. Alleles may disappear from the population simply by chance.
d. Allele frequencies do not change.
e. The mean trait value decreases from one generation to another.

negative directional selection
e
In a normal distribution, 99% of the measurements fall within
Question options:

1% of the mean.

5% of the mean.

plus or minus one standard deviation of the mean.

plus or minus two standard deviations of the mean.

plus or minus three standard deviations of the mean.
plus or minus three standard deviations of the mean
Any change in a population from Hardy-Weinberg equilibrium can be defined as ______.
Question options:

mutation

genetic equilibrium

migration

evolution

natural selection
evolution
Two highly inbred tobacco plants are crossed. One has dark green leaves. The other has yellow leaves. The F1 have light green leaves. Five hundred progeny from F1 × F1 crosses are analyzed. Their leaves show continuous variation in color, but none has dark green or yellow leaves. What do these data suggest about the number of genes determining this trait?
Question options:

There are 2 genes that determine this trait.

There are 3 genes that determine this trait.

There are 4 genes that determine this trait.

There are more than 4 genes that determine this trait.
There are more than 4 genes that determine this trait
Flower diameter in sunflowers is a quantitative trait. A plant with 6-cm flowers, from a highly inbred strain, is crossed to a plant with 30-cm flowers, also from a highly inbred strain. The F1 have 18-cm flowers. F1 × F1 crosses yield F2 plants with flowers ranging from 6 to 30 cm in diameter, in approximately 4-cm intervals (6, 10, 14, 18, 22, 26, 30).
Reference: Ref 24-1

The number of different genes influencing flower diameter in this plant is
Question options:

3.

4.

5.

6.

7.
3
T or F, Heritability indicates the degree to which a characteristic is genetically determined.
False
T or F, QTL mapping often provides an overestimate of the number of genes contributing to a quantitative trait
False
T or F, Genetic correlations result from pleiotropy.
True
Pleiotropy occurs when
1 gene influences multiple phenotypic traits
T or F, Measures of heritability are specific to a defined population in a given environment.
True
T or F, Allelic frequencies within populations are affected by dominance and recessiveness.
False
Match each term to the appropriate letter choice.
a. additive, dominance, genic interaction
b. distribution around the mean
c. phenotype proportions
d. pleiotropy
e. bell-shaped
f. regression coefficient
g. relationship between variables
h. correlation coefficient

regression
g
The probability that two alleles are identical by descent is the
inbreeding coefficient
A measure of the dispersion of a continuous distribution.
varience
______________ can cause the same genotype to produce a range of potential phenotypes.
Question options:

Epistasis

The inbreeding coefficient

Hybrid vigor

Environmental effects

Heritability
environmental effects
Flower diameter in sunflowers is a quantitative trait. A plant with 6-cm flowers, from a highly inbred strain, is crossed to a plant with 30-cm flowers, also from a highly inbred strain. The F1 have 18-cm flowers. F1 × F1 crosses yield F2 plants with flowers ranging from 6 to 30 cm in diameter, in approximately 4-cm intervals (6, 10, 14, 18, 22, 26, 30).
Reference: Ref 24-1

An 18-cm F1 plant is crossed to a 6-cm plant. What is the probability of an offspring with one additive allele, if all genes that influence this trait are unlinked?
Question options:

1/3

1/4

1/6

3/8

1/16
3/8
Which of the following polymorphisms is the most efficient for use in population genetics studies?
Question options:

Amino acid sequence polymorphisms

Restriction site variation

Chromosomal polymorphisms

Complete sequence variation

Variable number of tandem repeats
complete sequence variation
Which of the following is NOT an explanation as to why dominant disease-causing genes exist in populations?
Question options:

A) The genes may be the result of new mutations.

B) The genes are masked and therefore are passed only through carriers.


C) Despite the genes' effects, individuals stay healthy enough to reproduce.


D) The genes exert their effects late in life, beyond reproductive age.
The genes are masked and therefore are passed only through carriers
Total phenotypic variance can be decomposed into all but one of these components:
Question options:

genetic-environment interaction variance.

genetic variance.

environmental variance.

heritability.
heritability
Evolution occurs:
only via natural selection, genetic drift, migration, or mutation
T or F, When narrow-sense heritability is high for a particular trait, offspring tend to resemble their parents for that trait.
True
Match the phenomenon to its effect on populations. There is only one best answer for each number. You may use letters more than once.
a. Allele frequencies become more similar across populations.
b. Generation of new alleles changes allele frequencies very slowly.
c. Alleles may disappear from the population simply by chance.
d. Allele frequencies do not change.
e. The mean trait value decreases from one generation to another.

mutation
b
Match each term to the appropriate letter choice.
a. additive, dominance, genic interaction
b. distribution around the mean
c. phenotype proportions
d. pleiotropy
e. bell-shaped
f. regression coefficient
g. relationship between variables
h. correlation coefficient

genetic varience
a
Match each term to the appropriate letter choice.
a. additive, dominance, genic interaction
b. distribution around the mean
c. phenotype proportions
d. pleiotropy
e. bell-shaped
f. regression coefficient
g. relationship between variables
h. correlation coefficient

covariance
h
A Mendelian population is defined by individuals
Question options:

interbreeding.

inbreeding.

evolving.

living in close proximity.

migrating.
interbreeding
Which of the following is the fastest way for an enzyme to respond to changing conditions in the cell?
Question options:

A) altering the enzyme's activity by allostearic effectors (activators or inhibitors)

B) changing the enzyme's compartmentalization or location in the cell

C) controlling the synthesis or degradation of the enzyme in the cell

D) covalently modifying the enzyme in the cell (by phosphorylation)
altering the enzyme's activity by allostearic effectors (activators or inhibitors)
To establish that evolution by natural selection is operating in a population, one must demonstrate variability for a trait, heritability of that trait, differential reproductive success based on that trait, and:
Question options:

continuous change in the environment.

progress.

random mating.

increased complexity of the organism.

nothing else.
nothing else
T or F, The heritability of a individual cannot be estimated
True
Match each term to the appropriate letter choice.
a. additive, dominance, genic interaction
b. distribution around the mean
c. phenotype proportions
d. pleiotropy
e. bell-shaped
f. regression coefficient
g. relationship between variables
h. correlation coefficient

slope
regression coefficient
Human racial differences are produced by
Question options:

A) cultural factors as well as multiple genes that affect several traits.

B) multiple genes that affect several traits.

C) multiple genes that affect skin color.

D) a single gene that affects skin color.
cultural factors as well as multiple genes that affect several traits
The continuous distribution of quantitative traits is attributed to the fact that traits are influenced both by ______________ and by _____________ factors.
a. environmental
b. dominance
c. measurement error
d. many loci
e. human error
d, a
Match the phenomenon to its effect on populations. There is only one best answer for each number. You may use letters more than once.
a. Allele frequencies become more similar across populations.
b. Generation of new alleles changes allele frequencies very slowly.
c. Alleles may disappear from the population simply by chance.
d. Allele frequencies do not change.
e. The mean trait value decreases from one generation to another.

population bottleneck
c
Population genetics is concerned with:
Question options:

how genes produce proteins.

how genes confer relative reproductive success on the individuals.

whether allele frequencies are changing over time.

how genes interact with one another.

(b) and (c) above.
(b) and (c)
Which of the following evolutionary forces does NOT change allele frequencies?
Question options:

nonrandom mating

mutation

selection

drift

migration
nonrandom mating
Match each term to the appropriate letter choice.
a. All genetic information within a Mendelian population
b. The mean trait value decreases from one generation to another
c. Any change in allele frequencies within a population
d. Probability of alleles being identical by descent
e. Alleles may disappear from the population simply by chance
f. Movement of genes
g. Generation of new alleles

migration
f
The cumulative contribution made by all the genes that contribute to a quantitative trait
additive effects
Match each term to the appropriate letter choice.
a. additive, dominance, genic interaction
b. distribution around the mean
c. phenotype proportions
d. pleiotropy
e. bell-shaped
f. regression coefficient
g. relationship between variables
h. correlation coefficient

genetic correlation
pleiotropy
Narrow-sense heritability for IQ scores has been estimated as 0.4. If the mean IQ score in the population is 100, what is the predicted IQ for a child whose parents both had IQ scores of 150?
120