1) For mapping studies of genomes, most of which were far
along before 2000, the three-stage method was often used. Which of the
following is the usual order in which the stages were performed, assuming some
overlap of the three?
A) genetic map, sequencing of fragments, physical map
B) linkage map, physical map, sequencing of fragments
C) sequencing of entire genome, physical map, genetic map
D) cytogenetic linkage, sequencing, physical map
E) physical map, linkage map, sequencing
Answer: B
2) What is the difference between a linkage map and a
physical map?
A) For a linkage map, markers are spaced by recombination
frequency, whereas for a physical map they are spaced by numbers of base pairs
(bp).
B) For a physical map, the ATCG order and sequence must
be achieved; however, it does not for the linkage map.
C) For a linkage map, it is shown how each gene is linked
to every other gene.
D) For a physical map, the distances must be calculable
in units such as nanometers.
E) There is no difference between the two except in the
type of pictorial representation.
Answer: A
3) How is a physical map of the genome of an organism
achieved?
A) using recombination frequency
B) using very high-powered microscopy
C) using restriction enzyme cutting sites
D) using sequencing of nucleotides
E) using DNA fingerprinting via electrophoresis
Answer: C
4) Which of the following most correctly describes a
shotgun technique for sequencing a genome?
A) genetic mapping followed immediately by sequencing
B) physical mapping followed immediately by sequencing
C) cloning large genome fragments into very large vectors
such as YACs, followed by sequencing
D) cloning several sizes of fragments into various size
vectors, ordering the clones, and then sequencing them
E) cloning the whole genome directly, from one end to the
other
Answer: D
5) The biggest problem with the shotgun technique is its
tendency to underestimate the size of the genome. Which of the following might
best account for this?
A) skipping some of the clones to be sequenced
B) missing some of the overlapping regions of the clones
C) counting some of the overlapping regions of the clones
twice
D) having some of the clones die during the experiment
and therefore not be represented
E) missing some duplicated sequences
Answer: E
6) What is metagenomics?
A) genomics as applied to a species that most typifies
the average phenotype of its genus
B) the sequence of one or two representative genes from
several species
C) the sequencing of only the most highly conserved genes
in a lineage
D) sequencing DNA from a group of species from the same
ecosystem
E) genomics as applied to an entire phylum
Answer: D
7) Which procedure is not required when the shotgun
approach to sequencing is modified as sequencing by synthesis, in which many
small fragments are sequenced simultaneously?
A) use of restriction enzymes
B) sequencing each fragment
C) cloning each fragment into a plasmid
D) ordering the sequences
E) PCR amplification
Answer: C
8) What is bioinformatics?
A) a technique using 3-D images of genes in order to
predict how and when they will be expressed
B) a method that uses very large national and
international databases to access and work with sequence information
C) a software program available from NIH to design genes
D) a series of search programs that allow a student to
identify who in the world is trying to sequence a given species
E) a procedure that uses software to order DNA sequences
in a variety of comparable ways
Answer: B
9) What is proteomics?
A) the linkage of each gene to a particular protein
B) the study of the full protein set encoded by a genome
C) the totality of the functional possibilities of a
single protein
D) the study of how amino acids are ordered in a protein
E) the study of how a single gene activates many proteins
Answer: B
10) Bioinformatics can be used to scan sequences for
probable genes looking for start and stop sites for transcription and for
translation, for probable splice sites, and for sequences known to be found in
other known genes. Such sequences containing these elements are called
A) expressed sequence tags.
B) cDNA.
C) multigene families.
D) proteomes.
E) short tandem repeats.
Answer: A
11) A microarray known as a GeneChip, with most now-known
human protein coding sequences, has been developed to aid in the study of human
cancer by first comparing two to three subsets of cancer subtypes. What kind of
information might be gleaned from this GeneChip to aid in cancer prevention?
A) information about whether or not a patient has this
type of cancer prior to treatment
B) evidence that might suggest how best to treat a
person's cancer with chemotherapy
C) data that could alert patients to what kind of cancer
they were likely to acquire
D) information about which parent might have provided a
patient with cancer-causing genes
E) information on cancer epidemiology in the United
States or elsewhere
Answer: C
12) What is gene annotation in bioinformatics?
A) finding transcriptional start and stop sites, RNA
splice sites, and ESTs
B) describing the functions of protein-coding genes
C) describing the functions of noncoding regions of the
genome
D) matching the corresponding phenotypes of different
species
E) comparing the protein sequences within a single phylum
Answer: A
13) Why is it unwise to try to relate an organism's
complexity with its size or number of cells?
A) A very large organism may be composed of very few
cells or very few cell types.
B) A single-celled organism, such as a bacterium or a
protist, still has to conduct all the complex life functions of a large
multicellular organism.
C) A single-celled organism that is also eukaryotic, such
as a yeast, still reproduces mitotically.
D) A simple organism can have a much larger genome.
E) A complex organism can have a very small and simple
genome.
Answer: B
14) Fragments of DNA have been extracted from the
remnants of extinct woolly mammoths, amplified, and sequenced. These can now be
used to
A) introduce into relatives, such as elephants, certain
mammoth traits.
B) clone live woolly mammoths.
C) study the relationships among woolly mammoths and
other wool-producers.
D) understand the evolutionary relationships among
members of related taxa.
E) appreciate the reasons why mammoths went extinct.
Answer: D
15) If humans have 2,900 Mb, a specific member of the
lily family has 120,000 Mb, and a yeast has ~13 Mb, why can't this data allow
us to order their evolutionary significance?
A) Size matters less than gene density.
B) Size does not compare to gene density.
C) Size does not vary with gene complexity.
D) Size is mostly due to "junk" DNA.
E) Size is comparable only within phyla.
Answer: C
16) Which of the following is a representation of gene
density?
A) Humans have 2,900 Mb per genome.
B) C. elegans has ~20,000 genes.
C) Humans have ~20,000 genes in 2,900 Mb.
D) Humans have 27,000 bp in introns.
E) Fritillaria has a genome 40 times the size of a human.
Answer: C
17) Why might the cricket genome have 11 times as many
base pairs as that of Drosophila melanogaster?
A) The two insect species evolved at very different
geologic eras.
B) Crickets have higher gene density.
C) Drosophila are more complex organisms.
D) Crickets must have more noncoding DNA.
E) Crickets must make many more proteins.
Answer: D
18) The comparison between the number of human genes and
those of other animal species has led to many conclusions, including
A) the density of the human genome is far higher than in
most other animals.
B) the number of proteins expressed by the human genome
is far more than the number of its genes.
C) most human DNA consists of genes for protein, tRNA,
rRNA, and miRNA.
D) the genomes of other organisms are most significantly
smaller than the human genome.
Answer: B
19) Barbara McClintock, who achieved fame for discovering
that genes could move within genomes, had her meticulous work ignored for
nearly four decades, but eventually won the Nobel Prize. Why was her work so
distrusted?
A) The work of women scientists was still not allowed to
be published.
B) Geneticists did not want to lose their cherished
notions of DNA stability.
C) There were too many alternative explanations for
transposition.
D) She allowed no one else to duplicate her work.
E) She worked only with maize, which was considered
"merely" a plant.
Answer: B
20) What is the most probable explanation for the
continued presence of pseudogenes in a genome such as our own?
A) They are genes that had a function at one time, but
that have lost their function because they have been translocated to a new
location.
B) They are genes that have accumulated mutations to such
a degree that they would code for different functional products if activated.
C) They are duplicates or near duplicates of functional
genes but cannot function because they would provide inappropriate dosage of
protein products.
D) They are genes with significant inverted sequences.
E) They are genes that are not expressed, even though
they have nearly identical sequences to expressed genes.
Answer: E
21) What characteristic of short tandem repeat DNA makes
it useful for DNA fingerprinting?
A) The number of repeats varies widely from person to
person or animal to animal.
B) The sequence of DNA that is repeated varies
significantly from individual to individual.
C) The sequence variation is acted upon differently by
natural selection in different environments.
D) Every racial and ethnic group has inherited different
short tandem repeats.
Answer: A
22) Alu elements account for about 10% of the human
genome. What does this mean?
A) Alu elements cannot be transcribed into RNA.
B) Alu elements evolved in very ancient times, before
mammalian radiation.
C) Alu elements represent the result of transposition.
D) No Alu elements are found within individual genes.
E) Alu elements are cDNA and therefore related to
retrotransposons.
Answer: C
23) A multigene family is composed of
A) multiple genes whose products must be coordinately
expressed.
B) genes whose sequences are very similar and that
probably arose by duplication.
C) the many tandem repeats such as those found in
centromeres and telomeres.
D) a gene whose exons can be spliced in a number of
different ways.
E) a highly conserved gene found in a number of different
species.
Answer: B
24) Which of the following can be duplicated in a genome?
A) DNA sequences above a minimum size only
B) DNA sequences below a minimum size only
C) entire chromosomes only
D) entire sets of chromosomes only
E) sequences, chromosomes, or sets of chromosomes
Answer: E
25) In comparing the genomes of humans and those of other
higher primates, it is seen that humans have a large metacentric pair we call
chromosome 2 among our 46 chromosomes, whereas the other primates of this group
have 48 chromosomes and any pair like the human chromosome 2 pair is not
present; instead, the primate groups each have two pairs of midsize acrocentric
chromosomes. What is the most likely explanation?
A) The ancestral organism had 48 chromosomes and at some
point a centric fusion event occurred and provided some selective advantage.
B) The ancestral organism had 46 chromosomes, but
primates evolved when one of the pairs broke in half.
C) At some point in evolution, human ancestors and
primate ancestors were able to mate and produce fertile offspring, making a new
species.
D) Chromosome breakage results in additional centromeres
being made in order for meiosis to proceed successfully.
E) Transposable elements transferred significantly large
segments of the chromosomes to new locations.
Answer: A
26) Unequal crossing over during prophase I can result in
one sister chromosome with a deletion and another with a duplication. A mutated
form of hemoglobin, known as hemoglobin Lepore, is known in the human
population. Hemoglobin Lepore has a deleted set of amino acids. If it was
caused by unequal crossing over, what would be an expected consequence?
A) If it is still maintained in the human population,
hemoglobin Lepore must be selected for in evolution.
B) There should also be persons born with, if not living
long lives with, an anti-Lepore mutation or duplication.
C) Each of the genes in the hemoglobin gene family must
show the same deletion.
D) The deleted gene must have undergone exon shuffling.
E) The deleted region must be located in a different area
of the individual's genome.
Answer: B
27) When does exon shuffling occur?
A) during splicing of DNA
B) during mitotic recombination
C) as an alternative splicing pattern in
post-transcriptional processing
D) as an alternative cleavage or modification
post-translationally
E) as the result of faulty DNA repair
Answer: C
28) What are genomic "hot spots"?
A) the locations that correspond to most genetic diseases
B) the areas of a genome that most often mutate due to
environmental effects
C) the locations that most often correspond with
chromosomal breakpoints
D) the locations that correspond to most genetic diseases
and the locations that most often correspond with chromosomal breakpoints
E) the locations that correspond to most genetic
diseases, the areas of a genome that most often mutate due to environmental
effects, and the locations that most often correspond with chromosomal
breakpoints
Answer: E
29) In order to determine the probable function of a
particular sequence of DNA in humans, what might be the most reasonable
approach?
A) Prepare a knockout mouse without a copy of this
sequence and examine the mouse phenotype.
B) Genetically engineer a mouse with a copy of this
sequence and examine its phenotype.
C) Look for a reasonably identical sequence in another
species, prepare a knockout of this sequence in that species, and look for the
consequences.
D) Prepare a genetically engineered bacterial culture
with the sequence inserted and assess which new protein is synthesized.
E) Mate two individuals heterozygous for the normal and
mutated sequences.
Answer: C
30) Homeotic genes contain a homeobox sequence that is
highly conserved among very diverse species. The homeobox is the code for that
domain of a protein that binds to DNA in a regulatory developmental process.
Which of the following would you then expect?
A) that homeotic genes are selectively expressed over
developmental time
B) that a homeobox-containing gene has to be a
developmental regulator
C) that homeoboxes cannot be expressed in nonhomeotic
genes
D) that all organisms must have homeotic genes
E) that all organisms must have homeobox-containing genes
Answer: A
31) Which of the following studies would not likely be
characterized as eco-devo?
A) the study of a particular species to see whether or
not it has developmental regulation
B) a study of the assortment of homeotic genes in the
zebra
C) a comparison of the functions of a particular homeotic
gene among four species of reptiles
D) studying the environmental pressures on developmental
stages such as the tadpole
E) a fossil comparison of organisms from the Devonian era
Answer: C
32) A recent report has indicated several conclusions
about comparisons of our genome with that of Neanderthals. This report
concludes, in part, that, at some period in evolutionary history, there was an
admixture of the two genomes. This is evidenced by
A) some Neanderthal sequences not found in humans.
B) a small number of modern H. sapiens with Neanderthal
sequences.
C) Neanderthal Y chromosomes preserved in the modern
population of males.
D) mitochondrial sequences common to both groups.
Answer: B
33. Types of DNA sequences in the human genome.
The pie chart in Figure represents the relative
frequencies of the following in the human genome:
I. repetitive DNA unrelated to transposons
II. repetitive DNA that includes transposons
III. unique noncoding DNA
IV. introns and regulatory sequences
V. exons
Which region is occupied by exons only (V)?
A) A
B) B
C) C
D) D
E) E
Answer: A
34. Types of DNA sequences in the human genome.
The pie chart in Figure 21.1 represents the relative
frequencies of the following in the human genome:
I. repetitive DNA unrelated to transposons
II. repetitive DNA that includes transposons
III. unique noncoding DNA
IV. introns and regulatory sequences
V. exons
Which region includes Alu elements and LI sequences?
A) A
B) B
C) C
D) D
E) E
Answer: E
35, See Fig
Shows a diagram of blocks of genes on human chromosome 16 and the locations of blocks of similar genes on four chromosomes of the mouse.
Shows a diagram of blocks of genes on human chromosome 16 and the locations of blocks of similar genes on four chromosomes of the mouse.
The movement of these blocks suggests that
A) during evolutionary time, these sequences have
separated and have returned to their original positions.
B) DNA sequences within these blocks have become
increasingly divergent.
C) sequences represented have duplicated at least three
times.
D) chromosomal translocations have moved blocks of
sequences to other chromosomes.
E) higher mammals have more convergence of gene sequences
related in function.
Answer: D
36. shows a diagram of blocks of genes on human
chromosome 16 and the locations of blocks of similar genes on four chromosomes
of the mouse.
Which of the following represents another example of
the same phenomenon as that shown in Figure
A) the apparent centric fusion between two chromosome
pairs of primates such as chimps to form the ancestor of human chromosome 2
B) the difference in the numbers of chromosomes in five
species of one genus of birds
C) the formation of several pseudogenes in the globin
gene family subsequent to human divergence from other primates
D) the high frequency of polyploidy in many species of
angiosperms
Answer: A
37. Multigene families include two or more nearly identical
genes or genes sharing nearly identical sequences. A classical example is the
set of genes for globin molecules, including genes on human chromosomes 11 and
16.
How might identical and obviously duplicated gene
sequences have gotten from one chromosome to another?
A) by normal meiotic recombination
B) by normal mitotic recombination between sister
chromatids
C) by transcription followed by recombination
D) by chromosomal translocation
E) by deletion followed by insertion
Answer: D
38. Multigene families include two or more nearly identical
genes or genes sharing nearly identical sequences. A classical example is the
set of genes for globin molecules, including genes on human chromosomes 11 and
16.
Several of the different globin genes are expressed
in humans, but at different times in development. What mechanism could allow
for this?
A) exon shuffling
B) intron activation
C) pseudogene activation
D) differential translation of mRNAs
E) differential gene regulation over time
Answer: E
39) Bioinformatics includes all of the following except
A) using computer programs to align DNA sequences.
B) analyzing protein interactions in a species.
C) using molecular biology to combine DNA from two
different sources in a test tube.
D) developing computer-based tools for genome analysis.
E) using mathematical tools to make sense of biological
systems.
Answer: C
40) One of the characteristics of retrotransposons is
that
A) they code for an enzyme that synthesizes DNA using an
RNA template.
B) they are found only in animal cells.
C) they generally move by a cut-and-paste mechanism.
D) they contribute a significant portion of the genetic
variability seen within a population of gametes.
E) their amplification is dependent on a retrovirus.
Answer: A
41) Homeotic genes
A) encode transcription factors that control the
expression of genes responsible for specific anatomical structures.
B) are found only in Drosophila and other arthropods.
C) are the only genes that contain the homeobox domain.
D) encode proteins that form anatomical structures in the
fly.
E) are responsible for patterning during plant
development.
Answer: A
42) Two eukaryotic proteins have one domain in common but
are otherwise very different. Which of the following processes is most likely
to have contributed to this similarity?
A) gene duplication
B) RNA splicing
C) exon shuffling
D) histone modification
E) random point mutations
Answer: C
