overdominance.
Sickle-cell heterozygotes have a selective advantage, exhibiting
-gene flow.
-overdominance.
-genetic drift.
-postzygotic isolation.
-genetic hitchhiking.
gene flow.
Immigration of individuals with different allele frequencies into a population causes
-gene flow.
-overdominance.
-genetic drift.
-postzygotic isolation.
-genetic hitchhiking.
All of these
In the Hardy-Weinberg model, the ideal population is
-very large.
-randomly mating.
-free of mutations.
-non-migrating.
-All of these
0.10.
If there are two alleles of a gene, B and b, and the frequency of the B allele (p) is 0.90, the frequency of the b allele (q) is
-0.81.
-0.30.
-0.10.
-0.09.
-0.01.
2pq.
For alleles of genes in Hardy-Weinberg equilibrium, the frequency of heterozygotes is represented as
-p.
-q.
-p2.
-q2.
-2pq.
Phenotypic observation
Which of the following methods is least useful for assessing levels of genetic variation in populations?
-DNA sequencing
-VNTRs
-Protein electrophoresis
-Phenotypic observation
-RFLP analysis
genetic hitchhiking.
Favorable alleles of genes can cause selection for an allele of an unrelated linked gene, a phenomenon known as
-gene flow.
-overdominance.
-genetic drift.
-postzygotic isolation.
-genetic hitchhiking.
postzygotic isolation.
Hybrid sterility is an example of
-gene flow.
-overdominance.
-genetic drift.
-postzygotic isolation.
-genetic hitchhiking.
genetic drift.
Very small, isolated populations are subject to
-gene flow.
-overdominance.
-genetic drift.
-postzygotic isolation.
-genetic hitchhiking.
0.35
If the genotypic frequencies in a population at Hardy-Weinberg equilibrium are 0.418 homozygous dominants, 0.457 heterozygotes, and 0.125 homozygous recessives, what is the frequency of the recessive allele?
-0.35
-0.65
-0.125
-0.875
-0.01
a cline.
Allele frequencies can change across the geographic range of a species according to climate, geological features, or direction in the range. For instance, a certain allele frequency might go up along with the elevation or down as you go south in the speci
Heterozygote advantage
Which of the following is not a form of genetic drift?
-Founder effect
-Nonrandom mating
-Population bottleneck
-Heterozygote advantage
-All of these are forms of genetic drift.
loss of genetic variation in a population.
Genetic drift may lead to
-loss of genetic variation in a population.
-a decrease in the mutation rate of a particular gene.
-increased heterozygosity at many loci.
-Hardy-Weinberg equilibrium.
-All of these
0.48
For a gene A, a geneticist studying a population of butterflies found the following genotypes:
108 AA butterflies
144 Aa butterflies
48 aa butterflies
What is the observed genotypic frequency of Aa individuals?
-0.144
-0.72
-0.40
-0.48
-1.44
0.40
For a gene A, a geneticist studying a population of butterflies found the following genotypes:
108 AA butterflies
144 Aa butterflies
48 aa butterflies
What is the frequency of the a allele in the butterfly population?
-0.16
-0.04
-0.40
-0.64
-48/300
changes in the amino acid sequence of proteins are likely to be harmful.
Synonymous mutations are found much more frequently than nonsynonymous mutations because
-mutations do not occur randomly
-the genetic code is redundant.
-of genetic drift.
-there is a selective advantage in looking like another species.
-changes in the a
Mutation
________ is the ultimate source of genetic variation in populations.
-Natural selection
-Genetic drift
-Gene flow
-Mutation
-Recombination
10
A population genetic study of a certain insect revealed four alleles for the GPI (glucose-phosphate isomerase) locus. How many different genotypic classes should be found?
-4
-8
-10
-16
-20
overdominance.
Heterozygotes for the sickle-cell allele show higher fitness than either homozygote genotype in malarial regions. This is an example of
-epistasis.
-pleiotropy.
-founder effect.
-overdominance.
-codominance.
gametic isolation.
Although bees carry pollen from tulip flowers to the blossoms on cherry trees, hybrid seeds are not produced because of
-gametic isolation.
-temporal isolation.
-ecological isolation.
-mechanical isolation.
-All of these
The genetic variation between human "races," such as Africans and Europeans, is less than the variation within a single race.
Choose the best answer.
-For two populations to remain genetically homogenized, a significant proportion of the population of each must be exchanged at least every other generation.
-When the population mean for a given measured trait is observed to decli
A selection coefficient of 1 means zero fitness.
Choose the best answer.
-The Hardy-Weinberg relationship cannot be used to compute allele frequencies when one or more alleles are recessive.
-Two closely related insect species are active at different times of day, with one diurnal and the other nocturna
Amino acids are most likely to be replaced with amino acids with similar chemical characteristics in homologous proteins.
What is replacement bias in homologous proteins?
-Mutations are rare events.
-Most dramatic alterations are removed from the gene pool by natural selection.
-Amino acids are most likely to be replaced with amino acids with similar chemical characteristics
All of these responses are correct
Genes evolve as a result of ___ in DNA.
-mutations
-duplications
-transpositions
-All of these responses are correct.
pseudogenes.
High rates of evolutionary change are observed in
-exons.
-the first nucleotide of sense codons.
-DNA regions corresponding to enzyme catalytic sites.
-pseudogenes.
transition
In DNA, ___ mutations appear to accumulate at a faster rate than other types of mutations.
-transition
-transversion
-translocation
-duplication
major histocompatibility complex
It appears that natural selection favors variability within ___ genes.
-histone
-apolipoprotein
-hemoglobin
-major histocompatibility complex
gene duplication.
Multigene families in eukaryotic genomes probably evolved as a result of
-gene duplication.
-translocation.
-transformation.
-gene duplication, translocation, and transformation.
A site may have undergone multiple substitutions and transitions accumulate at a faster rate than transversions.
Which of the following is a possible reason for underestimating the number of substitutions that has occurred since two homologous sequences last shared a common ancestor?
-A site may have undergone multiple substitutions. -Transitions accumulate at a fas
codon usage bias
Of the six codons that signify the amino acid leucine in yeast, approximately 80% of the leucine codons are UUG. This indicates that ___ is occurring.
-exon shuffling
-nonsynonymous substitution
-codon usage bias
-gene conversion
genetic mutations are rare events.
Parsimony-based sequence alignment methods rely on the assumption that
-genetic mutations are rare events.
-trees should be constructed from data obtained from a large number of mutations.
-genetic mutations occur on a regular basis over time.
-None of th
homologous
Proteins that are ___ share a common ancestry.
-homogenous
-homologous
-homozygous
-phylogenetic
ten times greater than
The average synonymous substitution rate in mitochondrial DNA is ___ the rate of synonymous substitutions in nuclear genes.
-a thousand times less than
-ten times greater than
-half
-double
1 and 2 share a more recent common ancestor than 1 and 3 or 2 and 3.
The content of guanine and cytosine (G + C) was compared among three types of bacteria (1, 2, and 3), and it was found that 1 and 2 were more similar in (G + C) to each other than either was to bacterium 3. Using the parsimony principle, you can conclude
the coding region of functional genes.
The lowest rates of evolutionary change are expected in
-pseudogenes.
-the third nucleotide of sense codons.
-the coding region of functional genes.
-the 3' flanking region of functional genes.
adherence of the gene to the codon usage bias of the organism
Which of the following is the best indicator of the relative amount of expression of a gene over an organism's lifetime?
-the rate of synonymous nucleotide substitutions
-the rate of accumulation of transversions versus transitions
-the amino acid sequenc
twice the divergence time.
The rate of nucleotide substitution between two DNA sequences can be determined by dividing the number of substitutions (observed by sequence alignment) by
-the divergence time.
-twice the divergence time.
-the fraction of nucleotides that differ.
-the di
16S rRNA
The tree of life proposed by Woese, Pace, and others in the mid 1980s grouped organisms according to the nucleotide sequence of ___ genes in various organisms.
-cytochrome C
-hemoglobin
-16S rRNA
-tRNA
B-A-C-D
Rank the following regions of a gene in terms of the relative rate of evolutionary change, from lowest to highest rate.
A:5' flanking region
B:coding sequence (nonsynonymous changes)
C: introns
D: 3' flanking region
-A-B-C-D
-D-C-B-A
-B-A-C-D
-D-C-A-B
Different parts of the same gene evolve at different rates.
Which of the following statements is true?
-Different genes in the same organism evolve at approximately the same rate.
-The same genes in different organisms evolve at approximately the same rate.
-Different parts of the same gene evolve at different rat
The rate of synonymous mutation is greater than the observed rate of nonsynonymous mutation.
Which of the following statements is true?
-The majority of synonymous mutations are detrimental to fitness.
-The majority of synonymous mutations are eliminated by natural selection.
-The majority of nonsynonymous mutations will become permanent substitu
the confidence level for nodes of the inferred trees
What does bootstrapping measure in phylogenetic tree reconstruction?
-evolutionary distance between two sequences
-the confidence level for nodes of the inferred trees
-the rate of evolutionary change between two sequences
-the number of possible trees
molecular clock.
If neutral base substitutions occur at random over time, it may be possible to use observed sequence divergence among a group of organisms as a
-measure of similarity and dissimilarity.
-molecular clock.
-means of confirming relationship.
-None of these s
Primate genes appear to be evolving at a slower overall rate than genes in all of these organisms.
Primate genes appear to be evolving at a slower overall rate than genes in
-rats.
-mice.
-rabbits.
-Primate genes appear to be evolving at a slower overall rate than genes in all of these organisms.
homologous proteins.
The molecular clock hypothesis correlates the rate of evolution to substitution rates in
-tRNA molecules.
-noncoding DNA sequences.
-homologous proteins.
-mtDNA.
The average synonymous substitution rate is higher than that for synonymous substitutions in nuclear genes.
Which of the following statements is true of mitochondrial DNA?
-The average synonymous substitution rate is higher than that for synonymous substitutions in nuclear genes.
-Mitochondrial DNA encodes only tRNAs and rRNAs.
-The mitochondrial genome is usua
bacteria.
According to the endosymbiont theory, mitochondria and chloroplasts arose from
-archaea.
-bacteria.
-small eukaryotes.
-None of the listed responses is correct.
An A-to-G or C-to-T mutation
Transition:
-A mutation that does not alter the encoded amino acid.
-An A-to-G or C-to-T mutation
-Nonfunctional evolutionary remnant of a gene
-A purine-to-pyrimidine mutation
-A mutation that alters the encoded amino acid
A purine-to-pyrimidine mutation
Transversion:
-A mutation that does not alter the encoded amino acid.
-An A-to-G or C-to-T mutation
-Nonfunctional evolutionary remnant of a gene
-A purine-to-pyrimidine mutation
-A mutation that alters the encoded amino acid
A mutation that does not alter the encoded amino acid.
Synonymous mutation:
-A mutation that does not alter the encoded amino acid.
-An A-to-G or C-to-T mutation
-Nonfunctional evolutionary remnant of a gene
-A purine-to-pyrimidine mutation
-A mutation that alters the encoded amino acid
A mutation that alters the encoded amino acid
Nonsynonymous:
-A mutation that does not alter the encoded amino acid.
-An A-to-G or C-to-T mutation
-Nonfunctional evolutionary remnant of a gene
-A purine-to-pyrimidine mutation
-A mutation that alters the encoded amino acid
Nonfunctional evolutionary remnant of a gene
Pseudogene:
-A mutation that does not alter the encoded amino acid.
-An A-to-G or C-to-T mutation
-Nonfunctional evolutionary remnant of a gene
-A purine-to-pyrimidine mutation
-A mutation that alters the encoded amino acid
share a common ancestor.
Homologous proteins
-share a common ancestor.
-share a common amino acid sequence.
-are determined by alleles on homologous chromosomes.
-A and B only
-A, B, and C
generally have no effect on the phenotype.
Synonymous changes that arise within coding sequences of genes
-generally have no effect on the phenotype.
-are usually detrimental to fitness.
-may be eliminated by natural selection.
-occur more frequently than nonsynonymous changes.
-B and C only
small deletions or insertions that produce gaps in sequence alignments.
Indels are
-index deletions used to identify a species.
-parsimonious trees.
-transitions and transversions combined.
-small deletions or insertions that produce gaps in sequence alignments.
-the result of codon usage bias.
introns, exons
Higher substitution rates are seen in ________ than in ________.
-coding regions, noncoding regions
-5' flanking regions, 3' flanking regions
-first codon positions, second codon positions
-introns, exons
-charged amino acid codons, noncharged amino acid
lead to amino acid change.
Nonsynonymous substitutions
-do not lead to amino acid change.
-lead to amino acid change.
-refer to substitutions in unrelated lineages.
-affect only certain amino acids.
-lead to transversions.
15
What is the number of possible unrooted trees for 5 taxa?
-5
-10
-15
-20
-25
Different regions of the same gene evolve at different rates.
Which of the following statements about molecular evolution is true?
-Homologous genes often evolve in the same way.
-Different regions of the same gene evolve at different rates.
-Genes in the same organism evolve at about the same rate.
-Genes in differ
All these are molecular evidence for evolution
Which of the following does not provide molecular evidence for evolution?
-The 1,000-fold differences in nonsynonymous substitutions between some genes
-The existence of pseudogenes
-The fact that high-expression genes use amino acids that are less energe
There has been a gene conversion.
With regards to the sequence alignment
G T C C A T C G G
G T C G A T C - G,
which of the following statements is not true?
-There has been a base deletion.
-There has been a base substitution.
-There has been a gene conversion.
-There has been a transvers
some codons are selectively favored over others.
Codon bias suggests that
-some codons evolved earlier than others.
-not all nonsynonymous substitutions are neutral.
-some codons are selectively favored over others.
-small fitness effects can make a large difference over time.
-some tRNAs are more abund
more energetically economical
From the standpoint of evolutionary fitness, it is expected that genes with a high rate of expression will make use of amino acids that are ________ than those amino acids used by genes with a low rate of expression.
-more common
-more energetically econo
Histones
Which of the following types of proteins evolves at the slowest rate?
-Peptide hormones
-Collagen
-Insulin
-Histones
-Lipoprotein
Mutations due to background cosmic radiation
Which of the following factors does not interfere with the interpretation of evolutionary time using the molecular clock?
-Horizontal gene transfer
-Differences in generation time
-Mutations due to background cosmic radiation
-Different selection pressure
found between individuals of African descent.
The greatest genetic differences found in humans are
-found between individuals from different continents.
-found between individuals of different racial groups.
-found between island populations and mainland populations.
-found between individuals of Afr
CUU to CUA
Which of the following mutations is considered a synonymous change?
-ACC to AUG
-CUU to AUU
-CUU to CUA
-UUU to UUA
10 times
The average synonymous substitution rate in mammalian mitochondrial genes is ________ the average rate for nuclear genes.
-2 times
-5 times
-10 times
-50 times
-100 times
A, B, and C
n the unweighted pair group method (UPGMA) of determining evolutionary relationships,
-each set of taxa is connected by the shortest genetic distance.
-a constant rate of evolution across all lineages is assumed.
-a distance matrix is first constructed.
-
phylogenetic trees.
Reconstructions of the evolutionary relationships of a set of taxa are called
-classifications.
-phylogenetic trees.
-UPGMA networks.
-networks.
-evolutionary scenarios.
All of these
The differences in evolutionary rates of change revealed by relative rate tests may be attributable to
-differential strength of selection.
-generation time.
-average DNA repair efficiency.
-differential exposure to mutagens.
-All of these
A, B, and C
_______ tend(s) to occur more frequently than ________.
-Synonymous substitutions, nonsynonymous substitutions
-Genetic divergence, genetic convergence
-Transitions, transversions
-A and B only
-A, B, and C
Both A and B are correct
Choose the best answer.
-The noncoding 5' flanking region of genes is more constrained by selection than the noncoding 3' flanking region.
-Many viruses are helped along in generating antibody-evading capsid protein variations by replication error.
-Pseud
None of the above are correct.
Choose the best answer.
A) The counterpart to the use of mtDNA to reconstruct maternal lineages is the use of chloroplast DNA to reconstruct paternal lineages.
B) High molecular similarity always reflects evolutionary relatedness.
C) Maximum confidence is
Both B and C are correct
(The fact that approximately 80% of the six codons that encode the amino acid leucine in yeast are UUG is an example of codon bias.
Genetic distance refers to the proportion of dissimilar nucleotides between two homologous sequenc
Choose the best answer.
-Nuclear autosomal DNA sequence is more abundant than mtDNA and is therefore preferable for use in reconstructing events like domestication or human migration.
-The fact that approximately 80% of the six codons that encode the amin
an enzyme that phosphorylate proteins important to the cell cycle.
A CDK is:
-a proteins that can stop the cell cycle.
-made and degraded at specific points in the cell cycle.
-a genes that produces abnormally active cell growth proteins.
-a normal growth-promoting gene.
-an enzyme that phosphorylate proteins important t
Are made and degraded at specific points in the cell cycle
Cyclins are:
-Proteins that can stop the cell cycle
-Are made and degraded at specific points in the cell cycle
-Genes that produce abnormally active cell growth proteins
-Normal growth-promoting genes
-Phosphorylate proteins important to the cell cycle
programmed cell death.
Apoptosis is
-rapid cell division.
-caused by proto-oncogenes.
-the change in shape of a cell when it becomes cancerous.
-programmed cell death.
-None of these
phosphorylation of cellular proteins.
Protein kinases are enzymes that normally catalyze the
-degradation of cellular proteins.
-phosphorylation of cellular proteins.
-formation of peptide bonds in proteins.
-phosphorylation of ADP.
-synthesis of kinins.
Both A and B are correct.
(SNPs are characterized by a single nucleotide difference in DNA sequence and are quite common, occurring once every one thousand bases in the human genome.)
Single nucleotide polymorphisms (SNPs)
-are characterized by a single nucleotide difference in DNA sequence.
-are quite common, occurring once every one thousand bases in the human genome.
-Both A and B are correct.
-Niether A nor B is correct.
Both A and B are correct.
Choose the correct response.
-Genetic illnesses caused by mutations associated with SNPs can be diagnosed accurately by genotyping the polymorphism.
-SNPs in non-coding regions can be useful as genetic markers in searches for disease genes.
-Both A and B
Heteroduplex analysis
________________ is a technique for identifying SNPs in tumor versus normal cells used in the Cancer Genome anatomy project to identify genes involved in various cancers.
-SNP analysis
-Heteroduplex analysis
-DNA sequencing
-Gel electrophoresis
-cDNA clon
At present, there are millions of SNPs stored in public and private databases, but their exploitation is limited by our inability to quickly, accurately, and cheaply genotype SNPs in the population at large.
Choose the correct response.
-Given that greater than 95% of the human genome contains non-coding DNA, it should not be surprising that SNPs are most common in those regions, where they have no impact on phenotype. Thus, such SNPs are of no value.
-At pre