6) Homologous proteins
A) share a common ancestor.
B) share a common amino acid sequence.
C) are determined by alleles on homologous chromosomes.
D) A and B only
E) A, B, and C
Skill: Factual recall
7) Synonymous changes that arise within coding sequences of genes
A) generally have no effect on the phenotype.
B) are usually detrimental to fitness.
C) may be eliminated by natural selection.
D) occur more frequently than nonsynonymous changes.
E) B and C only
Skill: Factual recall
8) Indels are
A) index deletions used to identify a species.
B) parsimonious trees.
C) transitions and transversions combined.
D) small deletions or insertions that produce gaps in sequence alignments.
E) the result of codon usage bias.
Skill: Factual recall
9) Higher substitution rates are seen in ________ than in ________.
A) coding regions, noncoding regions
B) 5' flanking regions, 3' flanking regions
C) first codon positions, second codon positions
D) introns, exons
E) charged amino acid codons, noncharged amino acid codons
Skill: Factual recall
10) Nonsynonymous substitutions
A) do not lead to amino acid change.
B) lead to amino acid change.
C) refer to substitutions in unrelated lineages.
D) affect only certain amino acids.
E) lead to transversions.
Skill: Factual recall
11) What is the number of possible unrooted trees for 5 taxa?
A) 5
B) 10
C) 15
D) 20
E) 25
Skill: Problem-solving
12) Which of the following statements about molecular evolution is true?
A) Homologous genes often evolve in the same way.
B) Different regions of the same gene evolve at different rates.
C) Genes in the same organism evolve at about the same rate.
D) Genes in different organisms evolve at about the same rate.
E) Nucleotide substitutions are nonrandom.
Skill: Factual recall
13) Which of the following does not provide molecular evidence for evolution?
A) The 1,000-fold differences in nonsynonymous substitutions between some genes
B) The existence of pseudogenes
C) The fact that high-expression genes use amino acids that are less energetically costly than those used by low-expression genes
D) The fact that there is a lower rate of nucleotide substitutions in coding regions than in noncoding regions of genes
E) All these are molecular evidence for evolution
Skill: Factual recall
14) 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?
A) There has been a base deletion.
B) There has been a base substitution.
C) There has been a gene conversion.
D) There has been a transversion.
E) There is evidence of an indel.
Skill: Factual recall
15) Which of the following mutations is considered a synonymous change?
A) ACC to AUG
B) CUU to AUU
C) CUU to CUA
D) CUU to CUA
E) UUU to UUA
Skill: Factual recall
16) Codon bias suggests that
A) some codons evolved earlier than others.
B) not all nonsynonymous substitutions are neutral.
C) some codons are selectively favored over others.
D) small fitness effects can make a large difference over time.
E) some tRNAs are more abundant than others.
Skill: Factual recall
17) 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.
A) more common
B) more energetically economical
C) more energetically costly
D) rarer
E) None of these
Skill: Factual recall
18) Which of the following types of proteins evolves at the slowest rate?
A) Peptide hormones
B) Collagen
C) Insulin
D) Histones
E) Lipoprotein
Skill: Factual recall
19) Which of the following factors does not interfere with the interpretation of evolutionary time using the molecular clock?
A) Horizontal gene transfer
B) Differences in generation time
C) Mutations due to background cosmic radiation
D) Different selection pressures on different taxonomic groups
E) Differences in DNA repair efficiency in different taxonomic groups
Skill: Conceptual understanding
20) The greatest genetic differences found in humans are
A) found between individuals from different continents.
B) found between individuals of different racial groups.
C) found between island populations and mainland populations.
D) found between individuals of African descent.
E) found between individuals of European descent.
Skill: Factual recall
21) The average synonymous substitution rate in mammalian mitochondrial genes is ________ the average rate for nuclear genes.
A) 2 times
B) 5 times
C) 10 times
D) 50 times
E) 100 times
Skill: Factual recall
22) In the unweighted pair group method (UPGMA) of determining evolutionary relationships,
A) each set of taxa is connected by the shortest genetic distance.
B) a constant rate of evolution across all lineages is assumed.
C) a distance matrix is first constructed.
D) A and B only
E) A, B, and C
Skill: Factual recall
23) Reconstructions of the evolutionary relationships of a set of taxa are called
A) classifications.
B) phylogenetic trees.
C) UPGMA networks.
D) networks.
E) evolutionary scenarios.
Skill: Factual recall
24) The differences in evolutionary rates of change revealed by relative rate tests may be attributable to
A) differential strength of selection.
B) generation time.
C) average DNA repair efficiency.
D) differential exposure to mutagens.
E) All of these
Skill: Factual recall
25) _______ tend(s) to occur more frequently than ________.
A) Synonymous substitutions, nonsynonymous substitutions
B) Genetic divergence, genetic convergence
C) Transitions, transversions
D) A and B only
E) A, B, and C
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