Question 1

Nonadaptive mechanisms of evolutionary change are:

Accepted Answer

A)  migration (gene flow) , mutation, and genetic drift.
B)  migration (gene flow) , balancing selection, and genetic drift.
C)  migration (gene flow) , sexual selection, and genetic drift.
D)  mutation, sexual selection, and genetic drift.
E)  mutation, genetic drift, and heterozygote advantage.

Question 2

Using visual observation of phenotypes to identify allele frequency rarely works because:

Accepted Answer

A)  most alleles are recessive and will not produce a visible phenotype.
B)  phenotype is not due to the alleles.
C)  multiple genes may control the phenotype.
D)  visual phenotypes are rare.
E)  phenotype is not an indication of genotype.

Question 3

A gene pool is comprised of what?

Accepted Answer

A)  all the genes in a population
B)  all the alleles within a population
C)  all the individuals within a population
D)  all the offspring within a population

Question 4

Dodos were flightless birds that have been extinct for about 300 years. Imagine that biologists found two surviving dodos on present-day Earth and mated this pair of birds. What would you expect of the resulting dodo population?

Accepted Answer

A)  The maximum number of alleles present for any gene in the new population is two.
B)  Certain neutral mutations in this dodo population could become fixed, given the small population size.
C)  Adaptations will occur in this population as a result of genetic drift.
D)  Due to a population bottleneck, the frequency of alleles in this new dodo population may be very different from the frequencies expected in larger (now nonexistent) populations.

Question 5

In contrast to positive and negative selection, _____ selection acts to maintain two or more alleles in a population.

Accepted Answer

A)  balancing
B)  disruptive
C)  stabilizing
D)  directional

Question 6

A population experiencing genetic drift will be in Hardy-Weinberg equilibrium.

Accepted Answer

A) True 
 B)False

Question 7

Why is DNA sequencing the gold standard for measuring genetic variation?

Accepted Answer

A)  It is the easiest method of identifying genetic variation.
B)  It uses mutations to detect differences in amino acid sequence.
C)  It relies on proteins instead of genetic sequence.
D)  It determines the exact genetic sequence, and thus the absolute variation in a population.
E)  It is the least accurate, and is not the gold standard.

Question 8

A gene in a diploid species has five different alleles. In any one population, the allele frequencies of all five alleles must add up to:

Accepted Answer

A)  one.
B)  two.
C)  five.
D)  ten.

Question 9

Using protein gel electrophoresis to measure genetic variation in populations has some drawbacks. Which of the following is/are problems with the technique?

Accepted Answer

A)  It can't detect synonymous mutations. That is, differences in DNA sequences that result in the same amino acid sequence can't be detected with this method.
B)  It can't detect differences in noncoding DNA.
C)  It can only be used with proteins that can be stained or otherwise labeled and visualized.
D)  It can't detect mutations that do not affect the mobility of a protein within the gel, even if the protein's amino acid sequence is changed.
E)  None of the answer options is correct.

Question 10

Like natural selection, genetic drift always leads to adaptations within populations; only mutations do not result in adaptations.

Accepted Answer

A) True 
 B)False

Question 11

Consider the following two populations and the frequencies of alleles at the FGFR-1 locus.   Allele 1  Allele 2  Allele 3  Allele 4  Population 1 0.250.250.250.25 Population 2 0.500.420.050.03\begin{array} { | l | l | l | l | l | } \hline & 	ext { Allele 1 } & 	ext { Allele 2 } & 	ext { Allele 3 } & 	ext { Allele 4 } \\hline 	ext { Population 1 } & 0.25 & 0.25 & 0.25 & 0.25 \\hline 	ext { Population 2 } & 0.50 & 0.42 & 0.05 & 0.03 \\hline\end{array} Population 1  Population 2 ​ Allele 1 0.250.50​ Allele 2 0.250.42​ Allele 3 0.250.05​ Allele 4 0.250.03​​  Which of the populations has greater allelic variation?

Accepted Answer

A)  population 1
B)  population 2
C)  Neither, allelic diversity is the same for both populations.

Question 12

How does gel electrophoresis allow researchers to observe genetic variation?

Accepted Answer

A)  Gel electrophoresis enables a scientist to identify dominant and recessive traits.
B)  Gel electrophoresis enables scientists to identify alleles that vary.
C)  Gel electrophoresis enables scientists to replicate a strand of DNA.
D)  Gel electrophoresis enables a scientist to link phenotype to genotype.
E)  Protein gel electrophoresis enables a scientist to sequence DNA.

Question 13

What is the fundamental concept that causes gel electrophoresis of proteins to work?

Accepted Answer

A)  Different proteins have different charges and sizes.
B)  Different proteins respond in the same way to dyes in a gel.
C)  Some proteins are enzymes and will react with molecules in the gel.
D)  All proteins have the same charge and will move through the gel at the same speed.
E)  All proteins will react with a dye to produce a band.

Question 14

In a hypothetical population of 1000 frogs there exists a gene with two alleles. 280 of the frogs are homozygous dominant (DD) , and 220 are homozygous recessive (dd) . What is the frequency of heterozygotes in the population?

Accepted Answer

A)  0) 0
B)  0) 28
C)  0) 22
D)  0) 50

Question 15

All genes have the same rate of accumulation of genetic differences.

Accepted Answer

A) True 
 B)False

Question 16

Imagine the following genotype frequencies in a population: p2 = 0.49, 2pq = 0.42, q2 = 0.09. Now assume that there is nonrandom mating where individuals with one genotype will only mate with individuals that also have their genotype. Assume this pattern of mating goes on until the frequency of heterozygotes is effectively zero. What will the frequency of allele p be in the population?

Accepted Answer

A)  0) 3
B)  0) 7
C)  0) 91
D)  0) 49
E)  1) 0

Question 17

What is the hypothetical long-term result of different mutations accumulating in different populations?

Accepted Answer

A)  the evolution of different species
B)  the extinction of one population
C)  merging the populations through migration
D)  fixation of the same alleles in both populations
E)  decreased genetic isolation

Question 18

Migration, genetic drift, and mutation are like natural selection in that they:

Accepted Answer

A)  result in evolution of a population.
B)  may alter the allele frequency in a population.
C)  may alter the genotype frequency in a population.
D)  are all methods of evolutionary change.
E)  All of these choices are correct.

Question 19

Recall that in Mendel's garden peas, the yellow gene determines flower color, with the A (yellow)  allele dominant to the a (green)  allele. In a population of 200 plants, the genotype frequencies are 50% AA, 25% Aa, and 25% aa. What are the allele frequencies?

Accepted Answer

A)  50% A, 50% a
B)  50% A, 25% a
C)  87.5% A, 12.5% a
D)  62.5% A, 37.5% a
E)  75% A, 25% a

Question 20

Which of the following statements is TRUE regarding natural populations?

Accepted Answer

A)  Consistent with Thomas Malthus's hypothesis, most populations expand geometrically generation after generation.
B)  Well-established populations are typically stable in size.
C)  Resource availability generally plays no role in the size of a population.
D)  All populations evolve rapidlytime is rarely a factor in evolution.

Exam 21: Evolution: How Genotypes and Phenotypes Change Over Time

Using visual observation of phenotypes to identify allele frequency rarely works because:

Correct Answer
verified

A gene in a diploid species has five different alleles. In any one population, the allele frequencies of all five alleles must add up to:

Correct Answer
verified

Why is DNA sequencing the gold standard for measuring genetic variation?

Correct Answer
verified

Nonadaptive mechanisms of evolutionary change are:

Correct Answer
verified

Like natural selection, genetic drift always leads to adaptations within populations; only mutations do not result in adaptations.

Correct Answer
verified

Recall that in Mendel's garden peas, the yellow gene determines flower color, with the A (yellow) allele dominant to the a (green) allele. In a population of 200 plants, the genotype frequencies are 50% AA, 25% Aa, and 25% aa. What are the allele frequencies?

Correct Answer
verified

What is the fundamental concept that causes gel electrophoresis of proteins to work?

Correct Answer
verified

Correct Answer
verified

In a hypothetical population of 1000 frogs there exists a gene with two alleles. 280 of the frogs are homozygous dominant (DD) , and 220 are homozygous recessive (dd) . What is the frequency of heterozygotes in the population?

Correct Answer
verified

Correct Answer
verified

All genes have the same rate of accumulation of genetic differences.

Correct Answer
verified

A gene pool is comprised of what?

Correct Answer
verified

What is the hypothetical long-term result of different mutations accumulating in different populations?

Correct Answer
verified

Migration, genetic drift, and mutation are like natural selection in that they:

Correct Answer
verified

How does gel electrophoresis allow researchers to observe genetic variation?

Correct Answer
verified

Using protein gel electrophoresis to measure genetic variation in populations has some drawbacks. Which of the following is/are problems with the technique?

Correct Answer
verified

In contrast to positive and negative selection, _____ selection acts to maintain two or more alleles in a population.

Correct Answer
verified

A population experiencing genetic drift will be in Hardy-Weinberg equilibrium.

Correct Answer
verified

Dodos were flightless birds that have been extinct for about 300 years. Imagine that biologists found two surviving dodos on present-day Earth and mated this pair of birds. What would you expect of the resulting dodo population?

Correct Answer
verified

Which of the following statements is TRUE regarding natural populations?

Correct Answer
verified

Exam 21: Evolution: How Genotypes and Phenotypes Change Over Time

Using visual observation of phenotypes to identify allele frequency rarely works because:

Correct AnswerverifiedShow Answer

A gene in a diploid species has five different alleles. In any one population, the allele frequencies of all five alleles must add up to:

Correct AnswerverifiedShow Answer

Why is DNA sequencing the gold standard for measuring genetic variation?

Correct AnswerverifiedShow Answer

Nonadaptive mechanisms of evolutionary change are:

Correct AnswerverifiedShow Answer

Like natural selection, genetic drift always leads to adaptations within populations; only mutations do not result in adaptations.

Correct AnswerverifiedShow Answer

Recall that in Mendel's garden peas, the yellow gene determines flower color, with the A (yellow) allele dominant to the a (green) allele. In a population of 200 plants, the genotype frequencies are 50% AA, 25% Aa, and 25% aa. What are the allele frequencies?

Correct AnswerverifiedShow Answer

What is the fundamental concept that causes gel electrophoresis of proteins to work?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

In a hypothetical population of 1000 frogs there exists a gene with two alleles. 280 of the frogs are homozygous dominant (DD) , and 220 are homozygous recessive (dd) . What is the frequency of heterozygotes in the population?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

All genes have the same rate of accumulation of genetic differences.

Correct AnswerverifiedShow Answer

A gene pool is comprised of what?

Correct AnswerverifiedShow Answer

What is the hypothetical long-term result of different mutations accumulating in different populations?

Correct AnswerverifiedShow Answer

Migration, genetic drift, and mutation are like natural selection in that they:

Correct AnswerverifiedShow Answer

How does gel electrophoresis allow researchers to observe genetic variation?

Correct AnswerverifiedShow Answer

Using protein gel electrophoresis to measure genetic variation in populations has some drawbacks. Which of the following is/are problems with the technique?

Correct AnswerverifiedShow Answer

In contrast to positive and negative selection, _____ selection acts to maintain two or more alleles in a population.

Correct AnswerverifiedShow Answer

A population experiencing genetic drift will be in Hardy-Weinberg equilibrium.

Correct AnswerverifiedShow Answer

Dodos were flightless birds that have been extinct for about 300 years. Imagine that biologists found two surviving dodos on present-day Earth and mated this pair of birds. What would you expect of the resulting dodo population?

Correct AnswerverifiedShow Answer

Which of the following statements is TRUE regarding natural populations?

Correct AnswerverifiedShow Answer

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