BIO FINAL EXAM

Question 1

In eukaryotes, there are several different types of RNA polymerase. Which type is
involved in transcription of mRNA for a globin protein?
A) RNA polymerase I
B) RNA polymerase II
C) RNA polymerase III
D) primase

Answer 1

B) RNA polymerase II

Question 2

Which of the following processes occurs in eukaryotic gene expression?
A) mRNA, tRNA, and rRNA are translated.
B) RNA polymerase binds to the terminator sequence.
C) A cap is added to the 5′ end of the mRNA.
D) RNA polymerase requires tRNA to elongate the molecule

Answer 2

C) A cap is added to the 5′ end of the mRNA.

Question 3

Which of the following processes correctly describes alternative RNA splicing?
A) It is a mechanism for increasing the rate of translation.
B) It can allow the production of proteins of different sizes and functions from a
single mRNA.
C) It can allow the production of similar proteins from different RNAs.
D) It increases the rate of transcription.

Answer 3

B) It can allow the production of proteins of different sizes and functions from a
single mRNA

Question 4

In an experimental situation, a student researcher inserts an mRNA molecule into a
eukaryotic cell after she has removed its 5′ cap and poly-A tail. Which of the following
processes would you expect her to find to have occurred?
A) The mRNA is quickly converted into a ribosomal subunit.
B) The cell adds a new poly-A tail to the mRNA.
C) The mRNA attaches to a ribosome and is translated, but more slowly.
D) The molecule is digested by enzymes because it is not protected at the 5′ end

Answer 4

D) The molecule is digested by enzymes because it is not protected at the 5′ end.

Question 5

How does the primary transcript in the nucleus of a eukaryotic cell compare to the
functional mRNA?
A) the primary transcript is the same size as the mRNA
B) the primary transcript is larger than the mRNA
C) the primary transcript is smaller than the mRNA
D) both the primary transcript and mRNA contain introns

Answer 5

B) the primary transcript is larger than the mRNA

Question 6

In eukaryotic cells, transcription cannot begin until
A) the two DNA strands have completely separated and exposed the promoter.
B) several transcription factors have bound to the promoter.
C) the 5 caps are removed from the mRNA.
D) the DNA introns are removed from the template.

Answer 6

B) several transcription factors have bound to the promoter.

Question 7

Why is sequencing an entire genome, such as that of C. elegans, a nematode,
important for genetic research?
A) It allows researchers to use the sequence to build a “better” nematode, which is
resistant to disease.
B) It allows research on a group of organisms we do not usually care much about.
C) A sequence that is found to have a particular function in the nematode is likely to
have a closely related function in vertebrates.
D) A sequence that is found to have no introns in the nematode genome is likely to have
acquired the introns from higher organisms.

Answer 7

A sequence that is found to have a particular function in the nematode is likely to
have a closely related function in vertebrates.

Question 8

Why are yeast cells frequently used as hosts for cloning?
A) They easily form colonies.
B) They can remove exons from mRNA.
C) They do not have plasmids.
D) They are eukaryotic cells.

Answer 8

D) They are eukaryotic cells.

Question 9

Pax6 is a gene that is involved in eye formation in many invertebrates, such as
Drosophila. Pax6 is also found in vertebrates. A Pax6 gene from a mouse can be
expressed in a fly and the protein (PAX6) leads to a compound fly eye. This information
suggests which of the following characteristics of this gene?
A) Pax6 genes are identical in nucleotide sequence.
B) PAX6 proteins have identical amino acid sequences.
C) Pax6 is highly conserved and shows shared evolutionary ancestry.
D) PAX6 proteins are different for formation of different kinds of eyes

Answer 9

C) Pax6 is highly conserved and shows shared evolutionary ancestry.

Question 10

Which of the following characteristics of Taq polymerase make it useful in the PCR
process?
A) It is heat stable and can withstand the heating step of PCR.
B) Only minute amounts are needed for each cycle of PCR.
C) It binds more readily than other polymerases to the primers.
D) It has regions that are complementary to the primers

Answer 10

A) It is heat stable and can withstand the heating step of PCR.

Question 11

Use the figure to answer the following question.
Which of the following enzymes was used to produce the molecule of DNA in the figure?
A) ligase
B) a restriction enzyme (endonuclease)
C) RNA polymerase
D) DNA polymerase

Answer 11

B) a restriction enzyme (endonuclease)

Question 12

For which of the following processes can dideoxyribonucleotides be used?
A) to separate different sized DNA fragments
B) to produce cDNA from mRNA
C) to sequence a DNA fragment
D) to visualize DNA expression

Answer 12

C) to sequence a DNA fragment

Question 13

What information is critical to the success of polymerase chain reaction (PCR) itself?
A) The DNA sequence of the ends of the DNA (i.e., for primer design) to be amplified
must be known.
B) The complete DNA sequence of the DNA to be amplified must be known.
C) The sequence of restriction-enzyme recognition sites in the DNA to be amplified must
be known.
D) The sequence of restriction-enzyme recognition sites in the DNA to be amplified and in
the plasmid where the amplified DNA fragment will be cloned must be known.

Answer 13

A) The DNA sequence of the ends of the DNA (i.e., for primer design) to be amplified
must be known.

Question 14

Which of the following correctly lists the processes in order for one cycle of
polymerase chain reaction (PCR)?
A) denature DNA; add fresh enzyme; anneal primers; add dNTPs; extend primers
B) anneal primers; denature DNA; extend primers
C) extend primers; anneal primers; denature DNA
D) denature DNA; anneal primers; extend primers

Answer 14

D) denature DNA; anneal primers; extend primers

Question 15

The final step in a Sanger DNA sequencing reaction is to run the DNA fragments on a
polyacrylamide gel. What purpose does this serve?
A) It adds ddNTP to the end of each DNA fragment.
B) It changes the length of the DNA fragments.
C) It separates DNA fragments based on their charge.
D) It separates DNA fragments generated during the sequencing reaction based on
one-nucleotide differences in their size.

Answer 15

D) It separates DNA fragments generated during the sequencing reaction based on
one-nucleotide differences in their size.

Question 16

How can a gene that contains introns be made shorter (but remain functional) for
genetic engineering purposes?
A) using a restriction enzyme (endonuclease) to cut the gene into shorter pieces
B) using reverse transcriptase to reconstruct the gene from its mRNA
C) using DNA polymerase to reconstruct the gene from its polypeptide product
D) using DNA ligase to put together fragments of the DNA that code for a particular
polypeptide

Answer 16

B) using reverse transcriptase to reconstruct the gene from its mRNA

Question 17

Which of the following enzymes is required to make complementary DNA (cDNA) from
RNA?
A) restriction enzymes (endonucleases)
B) helicase
C) DNA ligase
D) reverse transcriptase

Answer 17

D) reverse transcriptase

Question 18

How have DNA microarrays made a huge impact on genomic studies?
A) They can be used to eliminate the function of any gene in the genome.
B) They can be used to introduce entire genomes into bacterial cells.
C) They allow the expression of many or even all of the genes in the genome to be
compared at once.
D) They allow physical maps of the genome to be assembled in a very short time

Answer 18

They allow the expression of many or even all of the genes in the genome to be
compared at once.

Question 19

RNAi methodology uses double-stranded pieces of RNA to trigger breakdown of a
specific mRNA or inhibit its translation. For which of the following processes might this
technique be useful?
A) to decrease the production from a harmful mutated gene
B) to destroy an unwanted allele in a homozygous individual
C) to form a knockout organism that will not pass the deleted sequence to its progeny
D) to raise the concentration of a desired protein

Answer 19

A) to decrease the production from a harmful mutated gene

Question 20

Which of the following statements correctly describes how RNA interference (RNAi)
silences selected genes?
A) Synthetic double-stranded RNA molecules stop transcription from occurring.
B) Synthetic double-stranded RNA molecules stop DNA replication from occurring.
C) Synthetic double-stranded RNA molecules trigger the breakdown of a gene’s
messenger RNA.
D) Synthetic double-stranded RNA molecules stop mitosis from occurring

Answer 20

C) Synthetic double-stranded RNA molecules trigger the breakdown of a gene’s
messenger RNA.

Question 21

n a comparison of two DNA sequences found in the same location on homologous
chromosomes, one of the homologs carries the sequence 5′-AACTACGA-3′, and the other
homolog carries the sequence
5′-AACTTCGA-3′. Within a population, you discover that each of these sequences is
common. Which of the following statements correctly describes theses sequences?
A) They contain a SNP that may be useful for genetic mapping.
B) They can identify a protein-coding region of a gene.
C) They may cause disease.
D) They may carry out RNA interference

Answer 21

A) They contain a SNP that may be useful for genetic mapping.

Question 22

Which of the following processes uses labeled probe to visualize the expression of
gene (i.e., mRNA) in whole tissues and organisms?
A) RT-PCR
B) in situ hybridization
C) DNA microarrays
D) RNA interference

Answer 22

B) in situ hybridization

Question 23

Which of the following statements correctly describes one of the main differences
between embryonic stem cells and adult stem cells?
A) Embryonic stem cells only differentiate into only eggs and sperm, and adult stem cells
differentiate into any type of cell.
B) Embryonic stem cells can give rise to all cell types in the organism, and adult
stem cells cannot.
C) Embryonic stem cells can continue to reproduce for an indefinite period, and adult stem
cells cannot.
D) One aim of using embryonic stem cells is to provide cells for repair of diseased tissue.

Answer 23

B) Embryonic stem cells can give rise to all cell types in the organism, and adult
stem cells cannot.

Question 24

In 1997, Dolly the sheep was cloned. Which of the following processes was used?
A) replication and dedifferentiation of adult stem cells from sheep bone marrow
B) separation of an early stage sheep blastula into separate cells, one of which was
incubated in a surrogate ewe
C) transfer of an adult cell’s nucleus into an enucleated sheep egg, followed by
incubation in a surrogate ewe
D) isolation of stem cells from a lamb embryo and production of a zygote equivalent

Answer 24

C) transfer of an adult cell’s nucleus into an enucleated sheep egg, followed by
incubation in a surrogate ewe

Question 25

In animals, what is the difference between reproductive cloning and therapeutic
cloning?
A) Reproductive cloning uses totipotent cells, whereas therapeutic cloning does not.
B) Reproductive cloning uses embryonic stem cells, whereas therapeutic cloning does not.
C) Therapeutic cloning uses nuclei of adult cells transplanted into enucleated unfertilized
eggs.
D) Therapeutic cloning supplies cells for repair of diseased or injured organs

Answer 25

D) Therapeutic cloning supplies cells for repair of diseased or injured organs

Question 26

In recent times, it has been shown that adult cells can be induced to become
pluripotent stem cells (iPS cells). To make this conversion, what has been done to the
adult cells?
A) A retrovirus is used to introduce four specific master regulatory genes.
B) The adult stem cells must be fused with embryonic cells.
C) Cytoplasm from embryonic cells is injected into the adult cells.
D) The nucleus of an embryonic cell is used to replace the nucleus of an adult cell.

Answer 26

A) A retrovirus is used to introduce four specific master regulatory genes.

Question 27

Transgenic mice are useful to human researchers because they ________.
A) can be valuable animal models of human disease
B) are essential for mapping human genes
C) are now used in place of bacteria for cloning human genes
D) were instrumental in pinpointing the location of the huntingtin gene

Answer 27

A) can be valuable animal models of human disease

Question 28

Which of the following information or processes does gene therapy require?
A) the knowledge and availability of the defective gene but not the normal allele
B) the ability to introduce the normal allele (i.e., normal gene) into the patient
C) the ability to express the introduced gene at any time in the tissue site within the patient
D) the ability to introduce a defective allele into a patient

Answer 28

B) the ability to introduce the normal allele (i.e., normal gene) into the patient

Question 29

Why might using retroviral vectors for gene therapy increase the patient’s risk of
developing cancer?
A) Retroviral vectors may introduce proteins from the virus.
B) Retroviral vectors do not express the genes that were introduced into a patient’s cells.
C) Retroviral vectors do not integrate their recombinant DNA into the patient’s genome.
D) Retroviral vectors integrate recombinant DNA into the genome in ways that may
misregulate the expression of genes at or near the site of integration

Answer 29

D) Retroviral vectors integrate recombinant DNA into the genome in ways that may
misregulate the expression of genes at or near the site of integration

Question 30

In DNA technology, the term vector can refer to
A) the enzyme that cuts DNA into restriction fragments.
B) the sticky end of a DNA fragment.
C) a SNP marker.
D) a plasmid used to transfer DNA into a living cell.

Answer 30

D) a plasmid used to transfer DNA into a living cell

Question 31

Which of the following tools of DNA technology is incorrectly paired with its use?
A) electrophoresis—separation of DNA fragments
B) DNA ligase—cutting DNA, creating sticky ends of restriction fragments
C) DNA polymerase—polymerase chain reaction to amplify sections of DNA
D) reverse transcriptase—production of cDNA from mRNA

Answer 31

B) DNA ligase—cutting DNA, creating sticky ends of restriction fragments

Question 32

paleontologist has recovered a bit of tissue from the 400-year-old preserved skin of
an extinct dodo (a bird). To compare a specific region of the DNA from a sample with DNA
from living birds, which of the following would be most useful for increasing the amount of
dodo DNA available for testing?
A) SNP analysis
B) polymerase chain reaction (PCR)
C) electroporation
D) gel electrophoresis

Answer 32

B) polymerase chain reaction (PCR)

Question 33

DNA technology has many medical applications. Which of the following is not done
routinely at present?
A) production of hormones for treating diabetes and dwarfism
B) analysis of gene expression for more informed cancer treatments
C) gene editing by the CRISPR-Cas9 system in viable human embryos to correct
genetic diseases
D) prenatal identification of genetic disease alleles

Answer 33

C) gene editing by the CRISPR-Cas9 system in viable human embryos to correct

Question 34

Which of the following is not true of cDNA produced using human brain tissue as the
starting material?
A) It can be amplified by the polymerase chain reaction.
B) It was produced from pre-mRNA using reverse transcriptase.
C) It can be labeled and used as a probe to detect genes expressed in the brain.
D) It lacks the introns of the pre-mRNA.

Answer 34

B) It was produced from pre-mRNA using reverse transcriptase.

Question 35

Expression of a cloned eukaryotic gene in a bacterial cell involves many challenges.
The use of mRNA and reverse transcriptase is part of a strategy to solve the problem of
A) post-transcriptional processing.
B) post-translational processing.
C) nucleic acid hybridization.
D) restriction fragment ligation

Answer 35

A) post-transcriptional processing.

Question 36

Which of the following processes is an early step in the whole-genome shotgun
approach to sequencing?
A) break genomic DNA at random sites
B) map the position of cloned DNA fragments
C) randomly select DNA primers and hybridize these to random positions of chromosomes
in preparation for sequencing

Answer 36

A) break genomic DNA at random sites

Question 37

Using modern techniques of sequencing by synthesis and the shotgun approach,
sequences are assembled into chromosomes by ________.
A) placing them on previously generated genetic maps
B) cloning them into plasmid vectors
C) computer analysis looking for sequence overlaps
D) cloning them into plasmid vectors, placing them on previously generated genetic maps,
followed by computer analysis looking for sequence overlaps

Answer 37

C) computer analysis looking for sequence overlaps

Question 38

Which of the following statements defines proteomics?
A) It is the linkage of each gene to a particular protein.
B) It is the study of the full protein set and its properties.
C) It is the totality of the functional possibilities of a single protein.
D) It is the study of how amino acids are ordered in a protein.

Answer 38

B) It is the study of the full protein set and its properties.

Question 39

Bioinformatics can be used to scan for short sequences that specify known mRNAs,
called ________.
A) expressed sequence tags (ESTs)
B) multigene families
C) proteomes
D) short tandem repeats

Answer 39

A) expressed sequence tags (ESTs)

Question 40

Which of the following processes correctly describes gene annotation in
bioinformatics?
A) finding transcriptional start and stop sites, RNA splice sites, and ESTs in DNA
sequences
B) assigning names to newly discovered genes
C) describing the functions of noncoding regions of the genome
D) matching the corresponding phenotypes of different species

Answer 40

A) finding transcriptional start and stop sites, RNA splice sites, and ESTs in DNA

Question 41

Bioinformatics includes ________.
I. using computer programs to align DNA sequences
II. creating recombinant DNA from separate species
III. developing computer-based tools for genome analysis
IV. using mathematical tools to make sense of biological systems
A) I and II
B) II and III
C) II and IV
D) I, III, and IV

Answer 41

D) I, III, and IV

Question 42

After finding a new medicinal plant, a pharmaceutical company decides to determine if
the plant has genes similar to those of other known medicinal plants. What would
annotation of the genome of this plant allow the company to determine?
A) what proteins are produced by the plant
B) what mRNA transcripts are produced by the plant
C) identify genes and determine their functions
D) identify the location of mRNA within the plant cells

Answer 42

C) identify genes and determine their functions

Question 43

If the sequence of a cDNA (i.e., complementary DNA or copy DNA) has matches with
DNA sequences in the genome, then this genomic DNA could be described by which of
the following statements?
A) The sequence codes for a protein.
B) The sequence codes for an rRNA.
C) The sequence is part of an intron.
D) The sequence is a regulatory sequence.

Answer 43

A) The sequence codes for a protein.

Question 44

Which of the following techniques would be most appropriate to test the hypothesis
that humans and chimps differ in the expression of a large set of shared genes?
A) DNA microarray analysis
B) polymerase chain reaction (PCR)
C) DNA sequencing
D) protein-protein interaction assay

Answer 44

A) DNA microarray analysis

Question 45

What can proteomics reveal that genomics cannot?
A) the number of genes characteristic of a species
B) the patterns of alternative splicing
C) the set of proteins present within a cell or tissue type
D) the movement of transposable elements within the genome

Answer 45

C) the set of proteins present within a cell or tissue type

Question 46

A sequence database such as GenBank could be used to carry out which of the
following processes?
A) Determine the expression pattern for specific human genes.
B) Construct a tree to determine the evolutionary relationships between various bird
species.
C) Search for genes that have not yet been identified in eukaryotic genomes.
D) Compare patterns of gene expression in cancerous and non-cancerous cells

Answer 46

B) Construct a tree to determine the evolutionary relationships between various bird
species

Question 47

Current analysis indicates that less than 2% of the human genome codes for proteins.
(True/False).

Answer 47

Answer: True

Question 48

Which of the following statements correctly describes one of the characteristics of
alternative splicing in vertebrate genomes?
A) Vertebrate genomes can produce more than one polypeptide from a single gene.
B) Vertebrate genomes can produce only one polypeptide from a single gene.
C) Vertebrate genomes are always smaller than other organisms.
D) Alternative splicing leaves introns in vertebrate genes after they are transcribed

Answer 48

A) Vertebrate genomes can produce more than one polypeptide from a single gene.

Question 49

Which of the following statements correctly describes one characteristic of
retrotransposons?
A) They use an RNA molecule as an intermediate in transposition.
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

Answer 49

A) They use an RNA molecule as an intermediate in transposition.

Question 50

How do transposons and retrotransposons differ in how they move around in a
genome?
A) Transposons move by viruses and retrotransposons move by plasmids.
B) Transposons move by means of a DNA intermediate and retrotransposons move
by means of an RNA intermediate.
C) Transposons move by means of a RNA intermediate and retrotransposons move by
means of an DNA intermediate.
D) Transposons move by viruses and retrotransposons move by bacteria

Answer 50

B) Transposons move by means of a DNA intermediate and retrotransposons move
by means of an RNA intermediate.

Question 51

Fragments of DNA have been extracted from the remnants of extinct woolly
mammoths, amplified, and sequenced. How can these fragments of DNA now be used?
A) to introduce certain mammoth traits into relatives, such as elephants
B) to clone live woolly mammoths
C) to understand the reasons why mammoths went extinct
D) to better understand the evolutionary relationships among members of related
taxa

Answer 51

D) to better understand the evolutionary relationships among members of related
taxa

Question 52

Bioinformatics includes all of the following except
A) using computer programs to align DNA sequences.
B) using DNA technology to combine DNA from two different sources in a test tube.
C) developing computer-based tools for genome analysis.
D) using mathematical tools to make sense of biological systems

Answer 52

B) using DNA technology to combine DNA from two different sources in a test tube.

Question 53

Which of the following molecules is a protein produced by a regulatory gene?
A) operon
B) inducer
C) promoter
D) repressor

Answer 53

D) repressor

Question 54

Which of the following molecules helps to “turn off” genes in a cell?
A) operon
B) inducer
C) promoter
D) corepressor

Answer 54

D) corepressor

Question 55

Which of the following conditions is most likely to cause the lactose operon to be
transcribed?
A) There is more glucose in the cell than lactose.
B) There is glucose but no lactose in the cell.
C) The cyclic AMP and lactose levels are both high within the cell.
D) The cAMP level is high and the lactose level is low.

Answer 55

C) The cyclic AMP and lactose levels are both high within the cell.

Question 56

How does the transcription of structural genes in an inducible operon occur?
A) It occurs continuously in the cell.
B) It starts when the pathway’s substrate is present.
C) It starts when the pathway’s product is present.
D) It stops when the pathway’s product is present.

Answer 56

B) It starts when the pathway’s substrate is present.

Question 57

Under what conditions does the trp repressor block transcription of the trp operon?
A) when the repressor binds to the inducer
B) when the repressor binds to tryptophan
C) when the repressor is not bound to tryptophan
D) when the repressor is not bound to the operator

Answer 57

B) when the repressor binds to tryptophan

Question 58

How does extracellular glucose inhibit transcription of the lac operon?
A) by strengthening the binding of the repressor to the operator
B) by weakening the binding of the repressor to the operator
C) by inhibiting RNA polymerase from opening the strands of DNA to initiate transcription
D) by reducing the levels of intracellular cAMP

Answer 58

D) by reducing the levels of intracellular cAMP

Question 59

Imagine that you’ve isolated a yeast mutant that contains histones resistant to
acetylation. What phenotype would you predict for this mutant?
A) The mutant will grow rapidly.
B) The mutant will require galactose for growth.
C) The mutant will show decreased levels of gene expression.
D) The mutant will show increased levels of gene expression.

Answer 59

C) The mutant will show decreased levels of gene expression.

Question 60

Which of the following statements correctly describes the primary difference between
enhancers and proximal control elements?
A) Enhancers are transcription factors; proximal control elements are DNA sequences.
B) Enhancers improve transcription; proximal control elements inhibit transcription.
C) Enhancers are located considerable distances from the promoter; proximal
control elements are close to the promoter.
D) Enhancers are DNA sequences; proximal control elements are proteins

Answer 60

C) Enhancers are located considerable distances from the promoter; proximal
control elements are close to the promoter.

Question 61

The reason for differences in the sets of proteins expressed in a nerve and a
pancreatic cell of the same individual is that nerve and pancreatic cells contain different
________.
A) genes
B) regulatory sequences
C) sets of regulatory proteins
D) promoters

Answer 61

C) sets of regulatory proteins

Question 62

Gene expression is often assayed by measuring the level of mRNA produced from a
gene. What level of the control of gene expression can by analyzed by this type of assay?
A) replication control
B) transcriptional control
C) alternative splicing
D) translational control

Answer 62

B) transcriptional control

Question 63

Which of the following processes would allow the detection of alternative splicing of
transcripts from a given gene?
A) Compare the DNA sequence of the given gene to that of a similar gene in a related
organism.
B) Measure the relative rates of transcription of the given gene compared to that of a gene
known to be constitutively spliced.
C) Compare the sequences of different primary transcripts made from the given gene.
D) Compare the sequences of different mRNAs made from the given gene

Answer 63

D) Compare the sequences of different mRNAs made from the given gene

Question 64

Which of the following mechanisms is used to coordinate the expression of multiple,
related genes in eukaryotic cells?
A) Environmental signals enter the cell and bind directly to promoters.
B) A given gene may have multiple enhancers, but each enhancer is generally
associated with only that gene and no other.
C) The genes are organized into a large operon, allowing them to be coordinately
controlled as a single unit.
D) A single repressor is able to turn off several related genes.

Answer 64

B) A given gene may have multiple enhancers, but each enhancer is generally
associated with only that gene and no other.

Question 65

DNA methylation and histone acetylation are examples of which of the following
processes?
A) genetic mutation
B) chromosomal rearrangements
C) epigenetic phenomena
D) translocation

Answer 65

C) epigenetic phenomena

Question 66

Which of the following functions are characteristic of general transcription factors in
eukaryotes?
A) They bind to other proteins or to the TATA box.
B) They inhibit RNA polymerase binding to the promoter and begin transcribing.
C) They usually lead to a high level of transcription even without additional specific
transcription factors.
D) They bind to sequences just after the start site of transcription

Answer 66

A) They bind to other proteins or to the TATA box.

Question 67

How are bacteria able to change their patterns of protein synthesis so quickly in
response to environmental changes?
A) mRNAs that are produced are short-lived and degraded within a few minutes of
being synthesized.
B) mRNA have long lifespans, allowing the bacteria to use them many times for
translation.
C) mRNA is stored for later use.
D) Operons are activated in the presence of transcription factors.

Answer 67

A) mRNAs that are produced are short-lived and degraded within a few minutes of

Question 68

A researcher found a method she could use to manipulate and quantify
phosphorylation and methylation in embryonic cells in culture. In one set of experiments,
she succeeded in increasing acetylation of histone tails in the chromatin of the cells.
Which of the following results would she most likely see in these cells?
A) increased chromatin condensation
B) decreased chromatin condensation
C) decreased binding of transcription factors
D) inactivation of the selected genes

Answer 68

B) decreased chromatin condensation

Question 69

A researcher found a method she could use to manipulate and quantify
phosphorylation and methylation in embryonic cells in culture. One of her colleagues
suggested she try increased methylation of cytosine (C) nucleotides in the DNA of
promoters of a mammalian system. Which of the following results would she most likely
see?
A) decreased chromatin condensation
B) activation of histone tails for enzymatic function
C) higher levels of transcription of certain genes
D) inactivation of the selected genes

Answer 69

D) inactivation of the selected genes

Question 70

Which of the following processes destroys RNA molecules in a cell if they have a
sequence complementary to an introduced double-stranded RNA?
A) RNA interference
B) RNA obstruction
C) RNA blocking
D) RNA disposal

Answer 70

A) RNA interference

Question 71

At the beginning of this century, there was a general announcement regarding the
sequencing of the human genome and the genomes of many other multicellular
eukaryotes. Many people were surprised that the number of protein-coding sequences
was much smaller than they had expected. Which of the following types of DNA make up
the rest of the human genome?
A) DNA that consists of histone coding sequences
B) DNA that is translated directly without being transcribed
C) non-protein-coding DNA that is transcribed into several kinds of small RNAs with
biological function
D) non-protein-coding DNA that serves as binding sites for reverse transcriptase

Answer 71

C) non-protein-coding DNA that is transcribed into several kinds of small RNAs with
biological function

Question 72

Which of the following statements best describes the characteristics of siRNA?
A) a double-stranded RNA, one of whose strands can complement and inactivate a
sequence of mRNA
B) a single-stranded RNA that can, where it has internal complementary base pairs, fold
into cloverleaf patterns
C) a double-stranded RNA that is formed by cleavage of hairpin loops in a larger precursor
D) a portion of rRNA that allows it to bind to several ribosomal proteins in forming large or
small subunits

Answer 72

A) a double-stranded RNA, one of whose strands can complement and inactivate a
sequence of mRNA

Question 73

A researcher introduces double-stranded RNA into a culture of mammalian cells and
can identify its location or that of its smaller subsections experimentally, using a
fluorescent probe. Some time later, she finds that the introduced strand separates into
single-stranded RNAs, one of which is degraded. What does this enable the remaining
strand to do?
A) attach to histones in the chromatin
B) bind to complementary regions of target mRNAs
C) activate other siRNAs in the cell
D) bind to noncomplementary RNA sequences

Answer 73

B) bind to complementary regions of target mRNAs

Question 74

A researcher introduces double-stranded RNA into a culture of mammalian cells and
can identify its location or that of its smaller subsections experimentally, using a
fluorescent probe. When she finds that the introduced strand separates into single-
stranded RNAs, what other evidence of this single-stranded RNA piece’s activity would
she find?
A) She can measure the degradation rate of the remaining single strand.
B) The rate of accumulation of the polypeptide encoded by the target mRNA is
reduced.
C) The amount of miRNA is multiplied by its replication.
D) The cell’s translation ability is entirely shut down

Answer 74

B) The rate of accumulation of the polypeptide encoded by the target mRNA is
reduced.

Question 75

The fact that plants can be cloned from somatic cells demonstrates that ________.
A) differentiated cells retain all the genes of the zygote
B) genes are lost during differentiation
C) the differentiated state is normally very unstable
D) differentiation does not occur in plants

Answer 75

A) differentiated cells retain all the genes of the zygote

Question 76

In colorectal cancer, several genes must be mutated for a cell to develop into a cancer
cell. Which of the following kinds of genes would you expect to be mutated?
A) genes coding for enzymes that act in the colon
B) genes involved in control of the cell cycle
C) genes that are especially susceptible to mutation
D) genes of the bacteria, which are abundant in the colon

Answer 76

B) genes involved in control of the cell cycle

Question 77

Which of the following statements describes a cell that is considered to be
differentiated?
A) The cell replicates by the process of mitosis.
B) The cell loses connections to the surrounding cells.
C) The cell produces proteins specific to a particular cell type.
D) The cell appears to be different from the surrounding cells

Answer 77

C) The cell produces proteins specific to a particular cell type.

Question 78

Which of the following functions does the product of the p53 gene carry out?
A) It inhibits the cell cycle.
B) It slows down the rate of DNA replication by interfering with the binding of DNA
polymerase.
C) It causes cells to reduce expression of genes involved in DNA repair.
D) It allows cells to pass on mutations due to DNA damage.

Answer 78

A) It inhibits the cell cycle.

Question 79

Which of the following statements correctly describes a characteristic of tumor-
suppressor gene?
A) They are frequently overexpressed in cancerous cells.
B) They are cancer-causing genes introduced into cells by viruses.
C) They encode proteins that help prevent uncontrolled cell growth.
D) They often encode proteins that stimulate the cell cycle

Answer 79

C) They encode proteins that help prevent uncontrolled cell growth.

Question 80

Why are BRCA1 and BRCA2 considered to be tumor-suppressor genes?
A) Their normal products participate in repair of DNA damage.
B) The mutant forms of either one of these prevent breast cancer.
C) The normal genes make estrogen receptors.
D) They block penetration of breast cells by chemical carcinogens

Answer 80

A) Their normal products participate in repair of DNA damage.

Question 81

Muscle cells differ from nerve cells mainly because they
A) express different genes.
B) contain different genes.
C) use different genetic codes.
D) have unique ribosomes

Answer 81

A) express different genes

Question 82

The functioning of enhancers is an example of
A) a eukaryotic equivalent of prokaryotic promoter functioning.
B) transcriptional control of gene expression.
C) the stimulation of translation by initiation factors.
D) post-translational control that activates certain proteins.

Answer 82

B) transcriptional control of gene expression.

Question 83

Cell differentiation always involves
A) transcription of the myoD gene.
B) the movement of cells.
C) the production of tissue-specific proteins.
D) the selective loss of certain genes from the genome

Answer 83

C) the production of tissue-specific proteins.

Question 84

Which of the following is an example of post-transcriptional control of gene
expression?
A) the addition of methyl groups to cytosine bases of DNA
B) the binding of transcription factors to a promoter
C) the removal of introns and alternative splicing of exons
D) gene amplification contributing to cancer

Answer 84

C) the removal of introns and alternative splicing of exons

Question 85

Which of the following statements about the DNA in one of your brain cells is true?
A) Most of the DNA codes for protein.
B) The majority of genes are likely to be transcribed.
C) It is the same as the DNA in one of your liver cells.
D) Each gene lies immediately adjacent to an enhancer.

Answer 85

C) It is the same as the DNA in one of your liver cells.

Question 86

Within a cell, the amount of protein made using a given mRNA molecule depends
partly on
A) the degree of DNA methylation.
B) the rate at which the mRNA is degraded.
C) the number of introns present in the mRNA.
D) the types of ribosomes present in the cytoplasm.

Answer 86

B) the rate at which the mRNA is degraded.

Question 87

The most direct ancestors of land plants were probably ________.
A) kelp (brown alga) that formed large beds near the shorelines
B) green algae
C) photosynthesizing prokaryotes (cyanobacteria)
D) liverworts and mosses

Answer 87

B) green algae

Question 88

About 450 million years ago, the terrestrial landscape on Earth would have ________.
A) looked very similar to that of today, with flowers, grasses, shrubs, and trees
B) been completely bare rock, with little pools that contained cyanobacteria and protists
C) been covered with tall forests in swamps that would become today’s coal
D) had non-vascular, green plants similar to liverworts forming green mats on rock

Answer 88

D) had non-vascular, green plants similar to liverworts forming green mats on rock

Question 89

Spores and seeds have basically the same function—dispersal—but are vastly
different because spores ________.
A) have a protective outer covering; seeds do not
B) have an embryo; seeds do not
C) have stored nutrition; seeds do not
D) are unicellular; seeds are not

Answer 89

D) are unicellular; seeds are not

Question 90

You find a green organism in a pond near your house and believe it is a plant, not an
alga. The mystery organism is most likely a plant and not an alga if it ________.
A) contains chloroplasts
B) is surrounded by a cuticle
C) does not contain vascular tissue
D) has cell walls that are comprised largely of cellulose

Answer 90

B) is surrounded by a cuticle

Question 91

If animals had alternation of generations like plants, ________.
A) they would have twice as rapid a population growth rate as compared to their current
rates
B) the products of mitosis would undergo meiosis
C) the products of meiosis would immediately fuse to form a zygote and then undergo
mitosis
D) the products of meiosis would undergo mitosis and become multicellular

Answer 91

D) the products of meiosis would undergo mitosis and become multicellular

Question 92

Apical meristems ________.
A) occur only in shoots of plants
B) occur only in roots of plants
C) occur in both roots and shoots of plants
D) allow plants to move from one place to another

Answer 92

C) occur in both roots and shoots of plants

Question 93

Which of the following statements about stomata is accurate?
A) Stomata are not important in algae because they do not need CO2.
B) Stomata, when closed, allow CO2 to diffuse into plants.
C) Stomata are important in terrestrial plants because they allow the roots to absorb water
and nutrients from the soil.
D) Stomata are important in terrestrial plants because they allow CO2 to diffuse into
the plant.

Answer 93

D) Stomata are important in terrestrial plants because they allow CO2 to diffuse into
the plant.

Question 94

The presence of vascular tissue allowed plants to ________.
A) absorb nutrients from the soil and form a symbiosis with fungi
B) transport nutrients and water from below-ground tissues to above-ground
tissues and grow taller
C) transport nutrients and water from below-ground tissues and use them to protect
developing embryos
D) release toxins into the soil that reduced competition with other plants by poisoning
nearby plants

Answer 94

B) transport nutrients and water from below-ground tissues to above-ground

Question 95

Bryophytes (non-vascular plants) ________.
A) are more similar to ancestral green algae than are vascular plants
B) are more similar to ancestral red algae than are vascular plants
C) can be included in the grade monilophyte because they do not have a complex
vascular system
D) are evolutionarily more advanced than seed plants

Answer 95

A) are more similar to ancestral green algae than are vascular plants

Question 96

Stomata ________.
A) occur in all land plants and define them as a monophyletic group
B) open to allow gas exchange and close to decrease water loss
C) occur in all land plants and are the same as pores
D) open to increase both water absorption and gas exchange

Answer 96

B) open to allow gas exchange and close to decrease water loss

Question 97

Liverworts, hornworts, and mosses are grouped together as bryophytes. Besides not
having vascular tissue, what do they all have in common?
A) They are all wind pollinated.
B) They are heterosporous.
C) They can reproduce asexually by producing gemmae.
D) They require water for reproduction

Answer 97

D) They require water for reproduction

Question 98

How are bryophytes and seedless vascular plants alike?
A) Plants in both groups have vascular tissue.
B) In both groups, sperm swim from antheridia to archegonia.
C) The dominant generation in both groups is the sporophyte.
D) Plants in both groups have true roots, stems, and leaves

Answer 98

B) In both groups, sperm swim from antheridia to archegonia.

Question 99

A botanist discovers a new species of plant in a tropical rain forest. Investigation of its
anatomy and life cycle shows the following characteristics: flagellated sperm, xylem with
tracheids, separate gametophyte, and sporophyte generations with the sporophyte
dominant, and no seeds. This plant is probably most closely related to ________.
A) mosses
B) ferns
C) gymnosperms
D) flowering plants

Answer 99

B) ferns

Question 100

In plants, which of the following are produced by meiosis?
A) haploid gametes
B) diploid gametes
C) haploid spores
D) diploid spores

Answer 100

C) haploid spores

Question 101

Which of the following features of how seedless land plants get sperm to egg are the
same as for some of their algal ancestors?
A) Conjugation tubes are formed between sperm and egg cells.
B) Packets of sperm are delivered by wind to the eggs.
C) Aquatic invertebrates carry sperm to eggs.
D) Flagellated sperm swim to the eggs in a water drop

Answer 101

D) Flagellated sperm swim to the eggs in a water drop

Question 102

Microphylls are found in which plant group?
A) lycophytes
B) liverworts
C) ferns
D) hornworts

Answer 102

A) lycophytes

Question 103

In addition to seeds, which of the following characteristics is unique to the seed-
producing plants?
A) sporopollenin
B) lignin present in cell walls
C) pollen
D) megaphylls

Answer 103

C) pollen

Question 104

The advantages of seeds, compared to spores, include ________.
A) using wind as a dispersal agent
B) containing a nutrient store for a developing sporophyte
C) relying on animals for pollination
D) providing nutrition for animals

Answer 104

B) containing a nutrient store for a developing sporophyte

Question 105

Which of the following sex and generation combinations directly produces the fruit of
angiosperms?
A) male gametophyte
B) female gametophyte
C) male sporophyte
D) female sporophyte

Answer 105

D) female sporophyte

Question 106

Which of the following is a characteristic of all angiosperms?
A) double internal fertilization
B) free-living gametophytes
C) carpels that contain microsporangia
D) ovules that are not contained within ovaries

Answer 106

A) double internal fertilization

Question 107

Robbie and Saurab are pre-med and pre-pharmacy students, respectively. They
complain to their biology professor that they should not have to study plants because
plants have little relevance to their chosen professions. Which of the following statements
are correct with regard to what physicians and pharmacists need to know about plants?
A) Land plants produce poisons and medicines.
B) Crop plants can often interbreed with their wild relatives.
C) Crop plants often produce more seeds than their wild relatives.
D) Land plants often provide food for pollinators

Answer 107

A) Land plants produce poisons and medicines.

Question 108

Which of the following is not a characteristic that distinguishes gymnosperms and
angiosperms from other plants?
A) dependent gametophytes
B) ovules
C) pollen
D) alternation of generations

Answer 108

D) alternation of generations

Question 109

Gymnosperms and angiosperms have the following in common except
A) seeds.
B) pollen.
C) ovaries.
D) ovules

Answer 109

C) ovaries.

Question 110

Which part of a plant absorbs most of the water and minerals taken up from the soil?
A) root cap
B) root hairs
C) the thick parts of the roots near the base of the stem
D) storage roots

Answer 110

B) root hairs

Question 111

Some of the largest leaves in the world can be found on plants near the floor of
dense tropical rain forests. Which of the following precursors for photosynthesis is most
likely limited in these large leaves?
A) oxygen
B) carbon dioxide
C) glucose
D) light

Answer 111

D) light

Question 112

hich of the following have unevenly thickened primary walls that support young,
growing parts of the plant?
A) parenchyma cells
B) collenchyma cells
C) sclerenchyma cells
D) tracheids and vessel elements

Answer 112

B) collenchyma cells

Question 113

Plant meristematic cells ________.
A) are distributed evenly in all tissues throughout the plant
B) are undifferentiated cells that produce new cells
C) increase the surface area of dermal tissue by developing root hairs
D) subdivide into three distinct cell types named parenchyma, ground meristem, and
procambium

Answer 113

B) are undifferentiated cells that produce new cells

Question 114

What is present in a shoot apical meristem region?
I) the region of cell division
II) immature buds and leaves
III) cells that will give rise to the protoderm, ground meristem, and procambium
A) only I
B) only II
C) only III
D) I, II, and III

Answer 114

D) I, II, and III

Question 115

Mitotic activity by the apical meristem of a root makes which of the following more
possible?
A) increased delivery of water to the aboveground stem
B) decreased absorption of mineral nutrients
C) increased absorption of carbon dioxide.
D) effective lateral growth of the stem

Answer 115

A) increased delivery of water to the aboveground stem

Question 116

You find a plant unfamiliar to you and observe that it has vascular bundles scattered
throughout the stem cross section. What do you conclude about the plant?
A) It is probably an herbaceous eudicot.
B) It will probably get annual rings of wood.
C) It is probably a monocot.
D) It could be either a young eudicot or a monocot

Answer 116

C) It is probably a monocot

Question 117

The following question is based on the drawings of root or stem cross sections shown
in the figure.
Refer to the figure. A monocot stem is represented by ________.
A) I only
B) II only
C) III only
D) IV only

Answer 117

B) II only

Question 118

The following question is based on the drawings of root or stem cross sections shown
in the figure.
Refer to the figure. A plant that is at least three years old is represented by ________.
A) I only
B) II only
C) III only
D) IV only

Answer 118

D) IV only

Question 119

The following diagram is of a cross section of a plant leaf. Use the diagram to answer
the question.
The main function associated with structure X is ________.
A) absorption of carbon dioxide
B) retention of water
C) collection of light
D) release of carbon dioxide

Answer 119

B) retention of water

Question 120

The following diagram is of a cross section of a plant leaf. Use the diagram to answer
the question.
The main function associated with structure Y is ________.
A) absorption of carbon dioxide
B) retention of water
C) collection of light
D) release of carbon dioxide

Answer 120

A) absorption of carbon dioxide

Question 121

Of the following plants, which stem has scattered vascular bundles?
A) corn
B) magnolia
C) chrysanthemum
D) hibiscus

Answer 121

A) corn

Question 122

Most of the growth of a plant body is the result of
A) cell differentiation.
B) morphogenesis.
C) cell division.
D) cell elongation

Answer 122

D) cell elongation

Question 123

Which of the following arise(s), directly or indirectly, from meristematic activity?
A) secondary xylem
B) leaves
C) dermal tissue
D) all of the above

Answer 123

D) all of the above

Question 124

Phloem sap can flow ________.
A) from leaves to shoots only
B) from shoots to leaves only
C) from sites of sugar production to storage units only
D) both ways between production and storage sites

Answer 124

D) both ways between production and storage sites

Question 125

A plant developed a mineral deficiency after being treated with a fungicide. What is
the most probable cause of the deficiency?
A) Mineral receptor proteins in the plant membrane were not functioning.
B) Mycorrhizal fungi were killed.
C) Active transport of minerals was inhibited.
D) The genes for the synthesis of transport proteins were destroyed.

Answer 125

B) Mycorrhizal fungi were killed.

Question 126

Active transport of amino acids in plants at the cellular level requires ________.
A) NADP and channel proteins
B) xylem membranes and channel proteins
C) sodium/potassium pumps and xylem membranes
D) ATP, transport proteins, and a proton gradient

Answer 126

D) ATP, transport proteins, and a proton gradient

Question 127

Which of the following primarily enters a plant somewhere other than through the
roots?
A) carbon dioxide
B) nitrogen
C) potassium
D) water

Answer 127

A) carbon dioxide

Question 128

Which of the following is a correct statement about sugar movement in phloem?
A) Diffusion can account for the observed rates of transport.
B) Movement can occur both upward and downward in the plant.
C) Sugar is translocated from sinks to sources.
D) Only phloem cells with nuclei can perform sugar movement.

Answer 128

B) Movement can occur both upward and downward in the plant.

Question 129

Which of the following is an adaptation that enhances the uptake of water and
minerals by roots?
A) mycorrhizae
B) pumping through plasmodesmata
C) active uptake by vessel elements
D) rhythmic contractions by cells in the root cortex

Answer 129

A) mycorrhizae

Question 130

Darwin and Wallace’s theory of evolution by natural selection was revolutionary
because it ________.
A) was the first theory to refute the ideas of special creation
B) proved that individuals acclimated to their environment over time
C) dismissed the idea that species are constant and emphasized the importance of
variation and change in populations
D) was the first time a biologist had proposed that species changed through time

Answer 130

C) dismissed the idea that species are constant and emphasized the importance of
variation and change in populations

Question 131

The Linnaeus classification system grouped organisms by ________.
A) linear hierarchy of the scala naturae
B) increasingly more general categories
C) increasingly more complex categories
D) environmental location

Answer 131

B) increasingly more general categories

Question 132

Fossils found in strata reveal that ________.
A) older strata carry fossils that differ greatly from living organisms
B) geologic changes occur quickly on Earth
C) unused body parts decrease in size
D) innate drive to complexity of life

Answer 132

A) older strata carry fossils that differ greatly from living organisms

Question 133

Prior to the work of Lyell and Darwin, the prevailing belief was that Earth is
________.
A) a few thousand years old, and populations are unchanging
B) a few thousand years old, and populations gradually change
C) millions of years old, and populations rapidly change
D) millions of years old, and populations are unchanging

Answer 133

A) a few thousand years old, and populations are unchanging

Question 134

The following questions refer to the figure below, which shows an outcrop of
sedimentary rock whose strata are labeled A-D.
If x indicates the location of fossils of two closely related species, then fossils of their most-
recent common ancestor are most likely to occur in which stratum?
A) A
B) B
C) C
D) D

Answer 134

C) C

Question 135

The cow Bos primigenius (which is bred for meat and milk) has a smaller brain and
larger eyes than closely related wild species of ungulates. These traits most likely arose by
________.
A) natural selection, because these traits evolved in the population over time
B) natural selection, because these traits were not consciously selected by humans
C) artificial selection, because changes in these traits co-occurred with human
selection for high milk output and high muscle content
D) artificial selection, because these animals differ from their close relatives and common

Answer 135

C) artificial selection, because changes in these traits co-occurred with human

Question 136

Starting from the wild mustard Brassica oleracea, breeders have created the strains
known as Brussels sprouts, broccoli, kale, and cabbage. Therefore, which of the following
statements is correct?
A) In this wild mustard, there is enough heritable variation to permit these different
varieties.
B) Heritable variation is low in wild mustard—otherwise this wild strain would have
different characteristics.
C) Natural selection is rare in wild populations of wild mustard.
D) In wild mustard, most of the variation is due to differences in soil or other aspects of the
environment.

Answer 136

A) In this wild mustard, there is enough heritable variation to permit these different
varieties.

Question 137

Which one of the following statements best defines artificial selection?
A) Process that occurs when individuals inherit traits that enable them to survive and
reproduce
B) Process where humans decide which plants and/or animals will not breed
C) Process of human directed breeding aimed to produce selective traits in selected
species
D) Process that favors beneficial mutations

Answer 137

C) Process of human directed breeding aimed to produce selective traits in selected
species

Question 138

Which of the following statements describe evolution?
A) Individuals evolve in response to their environment.
B) The match between organism and their environment decreases.
C) Natural selection chooses the most popular trait.
D) Quick changes occur in an individual’s phenotype.

Answer 138

A) Individuals evolve in response to their environment.

Question 139

Currently, two of the living elephant species (X and Y) are placed in the genus
Loxodonta, and a third surviving species (Z) is placed in the genus Elephas. Assuming this
classification reflects evolutionary relatedness, which of the following is the most accurate
phylogenetic tree?

Answer 139

D)

Question 140

Scientific theories ________.
A) are nearly the same things as hypotheses
B) are supported by, and make sense of, many observations
C) cannot be tested because the described events occurred only once
D) are predictions of future events

Answer 140

B) are supported by, and make sense of, many observations

Question 141

Structures as different as human arms, bat wings, and dolphin flippers contain many
of the same bones, which develop from similar embryonic tissues. These structural
similarities are an example of ________.
A) homology
B) convergent evolution
C) the evolution of common structure as a result of common function
D) the evolution of similar appearance as a result of common function

Answer 141

A) homology

Question 142

DNA sequences in many human genes are very similar to the sequences of
corresponding genes in chimpanzees. The most likely explanation for this result is that
A) humans and chimpanzees share a relatively recent common ancestor.
B) humans evolved from chimpanzees.
C) chimpanzees evolved from humans.
D) convergent evolution led to the DNA similarities

Answer 142

A) humans and chimpanzees share a relatively recent common ancestor.

Question 143

Which of the following people developed a theory of evolution almost identical to
Charles Darwin’s?
A) Charles Lyell
B) Alfred Wallace
C) Louis Pasteur
D) Gregor Mendel

Answer 143

B) Alfred Wallace

Question 144

Which of the following is the best modern definition of evolution?
A) descent with modification
B) change in the number of genes in a population over time
C) survival of the fittest
D) inheritance of acquired characters

Answer 144

A) descent with modification

Question 145

Microevolutions occur when ________.
A) a bird has a beak of a particular size that does not grow larger during a drought
B) changes in allele frequencies in a population occur over generations
C) gene flow evenly transfers alleles between populations
D) individuals within all species vary in their phenotypic traits

Answer 145

B) changes in allele frequencies in a population occur over generations

Question 146

Natural selection changes allele frequencies because some ________ survive and
reproduce better than others.
A) alleles
B) loci
C) species
D) individuals

Answer 146

D) individuals

Question 147

A section of DNA has the base sequence shown in #1. A mutation in this DNA strand
results in the base sequence shown in #2. What type of mutation does this change
represent?
#1 5’ - AGCGTTACCGT-3’
#2 5’- AGGCGTTACCGT-3’
A) a missense mutation
B) a point mutation
C) a silent mutation
D) frameshift mutation

Answer 147

D) frameshift mutation

Question 148

A single base substitution mutation is likely to have a less harmful effect when the
base change results in which of the following?
A) a stop codon
B) a codon that specifies the same amino acid as the original codon
C) an amino acid substitution that alters the tertiary structure of the protein
D) an amino acid substitution at the active site of an enzyme

Answer 148

B) a codon that specifies the same amino acid as the original codon

Question 149

Which of the following changes in an exon is most likely to result in a nonfunctional
protein product?
A) a base-pair deletion
B) an addition of three nucleotides
C) a substitution in the last base of a codon
D) a codon deletion

Answer 149

A) a base-pair deletion

Question 150

Which of the following molecules directly participates in the process of translation?
A) mRNA, tRNA, DNA, and rRNA
B) mRNA, DNA, and rRNA
C) mRNA, tRNA, and rRNA
D) mRNA, tRNA, and DNA

Answer 150

C) mRNA, tRNA, and rRNA

Question 151

An mRNA molecule with the sequence 5′-CCG-ACG-3′is being read by a ribosome.
During translation which of the following tRNA anticodons will be the first to productively
bind with this mRNA?
A) 3′-GGC-5′
B) 5′-GGC-3′
C) 5′-UGC-3′
D) 3′-UGC-5′

Answer 151

A) 3′-GGC-5′