Biology Ch 17-22

Front 1

Catastrophism, meaning the regular occurrences of geological or meteorlogical disturbances (catastrophes), was Cuvier's attempt to explain the existence of:

a) the fossil record

b) evolution

c) uniformitarianism

d) natural selection

Back 1

a) the fossil record

Front 2

Which of the following cuts DNA molecules at specific locations?

a) gel electrophoresis

b) gene cloning

c) restriction enzymes

Back 2

c) restriction enzymes

Front 3

A particular triplet of bases in the coding (non-template) sequence of DNA is AAA. The anticodon on the tRNA that binds the mRNA codon is:

a) UUA

b) TTT

c) AAA

d) UUU

Back 3

d) UUU

Front 4

Plants derived sexually from the same plant are ____ while those derived from somatic tissue from the same plant are ____.

a) identical, different

b) different, also different

c) different, identical

d) plants cannot be derived from somatic tissue

Back 4

c) different, identical

Front 5

Which of the following is NOT directly involved with translation and protein synthesis?

a) mRNA

b) anticodons

c) mitochondrial DNA

d) ribosomes

e) amino acids

Back 5

c) mitochondrial DNA

Front 6

The anticodon of a particular tRNA molecule is:

a) changeable, depending on the amino acid that attaches to the tRNA

b) complementary to the corresponding mRNA codon

c) complementary to the corresponding triplet in rRNA

d) the part of tRNA that bonds to a specific amino acid

Back 6

b) complementary to the corresponding mRNA codon

Front 7

Which of the following procedures would produce RFLPs?

a) incubating DNA fragments with "sticky ends" using ligase

b) incubating a mixture of single-stranded DNA from two closely related species

c) incubating DNA with restriction enzymes

d) incubating DNA nucleotides with DNA polymerase

Back 7

c) incubating DNA with restriction enzymes

Front 8

A paleontologist has recovered a bit of tissue from the 400-year-old preserved skin of an extinct dodo bird. The researcher would like to compare a specific region of the DNA from the sample with DNA from the living birds. Which of the following would be most useful for increasing the amount of dodo DNA available for testing?

a) RFLP analysis

b) Southern blotting

c) polymerase chain reaction (PCR)

d) electroporation

Back 8

c) polymerase chain reaction (PCR)

Front 9

Anteaters and some whales lack teeth as adults. The presence of teeth in the embryos of these creatures is evidence that:

a) all animals must undergo some type of embryological mutation during development

b) the embryos have a very different diet from that of the adults

c) these species are the product of artificial selection

d) these species share a common ancestry with animals that have adult teeth

Back 9

d) these species share a common ancestry with animals that have adult teeth

Front 10

In gel electrophoresis DNA molecules migrate from ____ to ____ ends of the gel.

a) acidic....basic

b) negative....positive

c) basic....acidic

d) positive....negative

Back 10

b) negative....positive

Front 11

According to Beadle and Tatum's working hypothesis based on their work with Neurospora bread mold, how many genes are necessary for the pathway? A ----enzyme A---> B -----enzyme B----->C

a) 0

b) 3

c) 1

d) 2

Back 11

d) 2

Front 12

Which of the following would NOT be considered a concern for critics of genetic engineering?

a) Genetically modified plants or animals could spread to wild species

b) Genetically modified foods may cause allergic reactions in unsuspecting consumers

c) Genetic engineering of herbicide-resistant crops may lead to increased use of herbicides

d) Genetic engineering of plants containing Bt toxin may be harmful to beneficial insect species

Back 12

c) genetic engineering of herbicide-resistant crops may lead to increased use of herbicides.

Front 13

Sequencing an entire genome, such as that of C. elegans, a nematode worm, is most important because

a) it allows researchers to use the sequence to build a "better" nematode, resistant to disease

b) a sequence that is found to have a particular function in the nematode is likely to have a closely related function in vertebrates, thus exhibiting an aspect of the unity of life

c) it allows research on a group of organisms we do not usually care much about

d) the nematode is a good animal model for trying out cures for viral illness

Back 13

b) a sequence that is found to have a particular function in the nematode is likely to have a closely related function in vertebrates, thus exhibiting an aspect of the unity of life

Front 14

There are 61 mRNA codons that specify an amino acid, but there are fewer tRNAs. This is best explained by the fact that:

a) competitive exclusion forces some tRNAs to be destroyed by nucleases

b) many codons are never used, so the tRNAs that recognize them are dispensible

c) the DNA codes for all 61 tRNAs but some are then destroyed

d) the rules for base pairing between the third base of a codon and tRNA are flexible or redundant

Back 14

d) the rules for base pairing between the third base of a codon and tRNA are flexible or redundant

Front 15

Darwin's mechanism of natural selection required long time spans in order for species to undergo modifications. From whom did Darwin get the concept of Earth's ancient age?

a) Charles Lyell

b) Alfred Wallace

c) Thomas Malthus

d) Georges Cuvier

Back 15

a) Charles Lyell

Front 16

In order to insert a human gene into a plasmid, both must____

a) have identical DNA sequences

b) originate from the same type of cell

c) code for the same gene product

d) be cut by the same restriction enzyme

e) be the same length

Back 16

d) be cut by the same restriction enzyme

Front 17

Where would a biology researcher NOT expect to find uracil and ribose sugar?

a) at the 3' end of an elongating strand of DNA

b) in a tRNA molecule attched to an amino acid

c) in the messenger RNA being read by a ribosome

d) in rRNA

Back 17

a) at the 3' end of an elongating strand of DNA

Front 18

Which of the following species is a product of artificial selection?

a) polar bear

b) Atlantic bluefin tuna

c) broccoli

d) monarch butterfly

Back 18

c) broccoli

Front 19

Which of the following is removed as the cell nucleus produces mature mRNA?

a) codons

b) introns

c) tRNA

d) exons

e) prometers

Back 19

b) introns

Front 20

DNA technology has many medical applications along with ethical considerations. Which of the following is not done routinely at present?

a) genetic testing for carriers of harmful alleles

b) epidemiology and forensic analysis of disease outbreaks

c) introduction of genetically engineered genes into human gametes

d) production of hormones for treating diabetes and HGH dwarfism.

Back 20

c) introduction of genetically engineered genes into human gametes

Front 21

A multicellular organism that carries a specific genetic change in each cell because of an intervention at the fertilized egg:

a) transversion

b) transition

c) transgenic

d) transformant

Back 21

c) transgenic

Front 22

The flow of information in a cell proceeds in what sequence?

Back 22

from DNA to RNA to protein

Front 23

A codon consists of _____ bases and specifies which _____ will be inserted into the polypeptide chain.

Back 23

three... amino acid

Front 24

A particular triplet of bases in the template strand of DNA is 5' AGT 3'. The corresponding codon for the mRNA transcribed is

Back 24

3' UCA 5'

Front 25

What is the function of RNA polymerase?

Back 25

It unwinds the double helix and adds nucleotides to a growing strand on RNA

Front 26

After an RNA molecule is transcribed from a eukaryotic gene, what are removed and what are spliced together to produce an mRNA molecule with a continuous coding sequence?

Back 26

introns...exons

Front 27

What is a ribozyme?

Back 27

a bioogical catalyst made of RNA

Front 28

In order for a eukaryotic gene to be engineered into a bacterial colony to be expressed, what must be included in addition to the coding exons of the gene?

Back 28

a bacterial promoter sequence

Front 29

A frameshift mutation could result from

Back 29

either an insertion or deletion of a base

Front 30

1) Which of the following variations on translation would be most disadvantageous for a cell?
A) translating polypeptides directly from DNA
B) using fewer kinds of tRNA
C) having only one stop codon
D) lengthening the half-life of mRNA
E) having a second codon (besides AUG) as a start codon

Back 30

A) translating polypeptides directly from DNA

Front 31

2) Garrod hypothesized that "inborn errors of metabolism" such as alkaptonuria occur because
A) metabolic enzymes require vitamin cofactors, and affected individuals have significant nutritional deficiencies.
B) enzymes are made of DNA, and affected individuals lack DNA polymerase.
C) many metabolic enzymes use DNA as a cofactor, and affected individuals have mutations that prevent their enzymes from interacting efficiently with DNA.
D) certain metabolic reactions are carried out by ribozymes, and affected individuals lack key splicing factors.
E) genes dictate the production of specific enzymes, and affected individuals have genetic defects that cause them to lack certain enzymes.

Back 31

A) metabolic enzymes require vitamin cofactors, and affected individuals have significant nutritional deficiencies.

Front 32

4) The nitrogenous base adenine is found in all members of which group?
A) proteins, triglycerides, and testosterone
B) proteins, ATP, and DNA
C) ATP, RNA, and DNA
D) α glucose, ATP, and DNA
E) proteins, carbohydrates, and ATP

Back 32

C) ATP, RNA, and DNA

Front 33

5) A particular triplet of bases in the template strand of DNA is 5' AGT 3'. The corresponding codon for the mRNA transcribed is
A) 3' UCA 5'.
B) 3' UGA 5'.
C) 5' TCA 3'.
D) 3' ACU 5'.
E) either UCA or TCA, depending on wobble in the first base.

Back 33

A) 3' UCA 5'.

Front 34

6) The genetic code is essentially the same for all organisms. From this, one can logically assume which of the following?
A) A gene from an organism can theoretically be expressed by any other organism.
B) All organisms have experienced convergent evolution.
C) DNA was the first genetic material.
D) The same codons in different organisms translate into the different amino acids.
E) Different organisms have different numbers of different types of amino acids.

Back 34

A) A gene from an organism can theoretically be expressed by any other organism.

Front 35

7) The "universal" genetic code is now known to have exceptions. Evidence for this can be found if which of the following is true?
A) If UGA, usually a stop codon, is found to code for an amino acid such as tryptophan (usually coded for by UGG only).
B) If one stop codon, such as UGA, is found to have a different effect on translation than another stop codon, such as UAA.
C) If prokaryotic organisms are able to translate a eukaryotic mRNA and produce the same polypeptide.
D) If several codons are found to translate to the same amino acid, such as serine.
E) If a single mRNA molecule is found to translate to more than one polypeptide when there are two or more AUG sites.

Back 35

A) If UGA, usually a stop codon, is found to code for an amino acid such as tryptophan (usually coded for by UGG only).

Front 36

8) Which of the following nucleotide triplets best represents a codon?
A) a triplet separated spatially from other triplets
B) a triplet that has no corresponding amino acid
C) a triplet at the opposite end of tRNA from the attachment site of the amino acid
D) a triplet in the same reading frame as an upstream AUG
E) a sequence in tRNA at the 3' end

Back 36

D) a triplet in the same reading frame as an upstream AUG

Front 37

9) Which of the following provides some evidence that RNA probably evolved before DNA?
A) RNA polymerase uses DNA as a template.
B) RNA polymerase makes a single-stranded molecule.
C) RNA polymerase does not require localized unwinding of the DNA.
D) DNA polymerase uses primer, usually made of RNA.
E) DNA polymerase has proofreading function.

Back 37

D) DNA polymerase uses primer, usually made of RNA.

Front 38

10) Which of the following statements best describes the termination of transcription in prokaryotes?
A) RNA polymerase transcribes through the polyadenylation signal, causing proteins to associate with the transcript and cut it free from the polymerase.
B) RNA polymerase transcribes through the terminator sequence, causing the polymerase to separate from the DNA and release the transcript.
C) RNA polymerase transcribes through an intron, and the snRNPs cause the polymerase to let go of the transcript.
D) Once transcription has initiated, RNA polymerase transcribes until it reaches the end of the chromosome.
E) RNA polymerase transcribes through a stop codon, causing the polymerase to stop advancing through the gene and release the mRNA.

Back 38

B) RNA polymerase transcribes through the terminator sequence, causing the polymerase to separate from the DNA and release the transcript.

Front 39

12) RNA polymerase in a prokaryote is composed of several subunits. Most of these subunits are the same for the transcription of any gene, but one, known as sigma, varies considerably. Which of the following is the most probable advantage for the organism of such sigma switching?
A) It might allow the transcription process to vary from one cell to another.
B) It might allow the polymerase to recognize different promoters under certain environmental conditions.
C) It could allow the polymerase to react differently to each stop codon.
D) It could allow ribosomal subunits to assemble at faster rates.
E) It could alter the rate of translation and of exon splicing.

Back 39

B) It might allow the polymerase to recognize different promoters under certain environmental conditions.

Front 40

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

Back 40

C) RNA polymerase II

Front 41

15) Transcription in eukaryotes requires which of the following in addition to RNA polymerase?
A) the protein product of the promoter
B) start and stop codons
C) ribosomes and tRNA
D) several transcription factors (TFs)
E) aminoacyl synthetase

Back 41

D) several transcription factors (TFs)

Front 42

16) A part of the promoter, called the TATA box, is said to be highly conserved in evolution. Which of the following might this illustrate?
A) The sequence evolves very rapidly.
B) The sequence does not mutate.
C) Any mutation in the sequence is selected against.
D) The sequence is found in many but not all promoters.
E) The sequence is transcribed at the start of every gene.

Back 42

C) Any mutation in the sequence is selected against.

Front 43

17) The TATA sequence is found only several nucleotides away from the start site of transcription. This most probably relates to which of the following?
A) the number of hydrogen bonds between A and T in DNA
B) the triplet nature of the codon
C) the ability of this sequence to bind to the start site
D) the supercoiling of the DNA near the start site
E) the 3-D shape of a DNA molecule

Back 43

A) the number of hydrogen bonds between A and T in DNA

Front 44

18) What is a ribozyme?
A) an enzyme that uses RNA as a substrate
B) an RNA with enzymatic activity
C) an enzyme that catalyzes the association between the large and small ribosomal subunits
D) an enzyme that synthesizes RNA as part of the transcription process
E) an enzyme that synthesizes RNA primers during DNA replication

Back 44

B) an RNA with enzymatic activity

Front 45

19) A transcription unit that is 8,000 nucleotides long may use 1,200 nucleotides to make a protein consisting of approximately 400 amino acids. This is best explained by the fact that
A) many noncoding stretches of nucleotides are present in mRNA.
B) there is redundancy and ambiguity in the genetic code.
C) many nucleotides are needed to code for each amino acid.
D) nucleotides break off and are lost during the transcription process.
E) there are termination exons near the beginning of mRNA.

Back 45

A) many noncoding stretches of nucleotides are present in mRNA.

Front 46

20) During splicing, which molecular component of the spliceosome catalyzes the excision reaction?
A) protein
B) DNA
C) RNA
D) lipid
E) sugar

Back 46

C) RNA

Front 47

21) Alternative RNA splicing
A) is a mechanism for increasing the rate of transcription.
B) can allow the production of proteins of different sizes from a single mRNA.
C) can allow the production of similar proteins from different RNAs.
D) increases the rate of transcription.
E) is due to the presence or absence of particular snRNPs.

Back 47

B) can allow the production of proteins of different sizes from a single mRNA.

Front 48

23) In an experimental situation, a student researcher inserts an mRNA molecule into a eukaryotic cell after he has removed its 5' cap and poly-A tail. Which of the following would you expect him to find?
A) The mRNA could not exit the nucleus to be translated.
B) The cell recognizes the absence of the tail and polyadenylates the mRNA.
C) The molecule is digested by restriction enzymes in the nucleus.
D) The molecule is digested by exonucleases since it is no longer protected at the 5' end.
E) The molecule attaches to a ribosome and is translated, but more slowly.

Back 48

D) The molecule is digested by exonucleases since it is no longer protected at the 5' end.

Front 49

30) Accuracy in the translation of mRNA into the primary structure of a polypeptide depends on specificity in the
A) binding of ribosomes to mRNA.
B) shape of the A and P sites of ribosomes.
C) bonding of the anticodon to the codon.
D) attachment of amino acids to tRNAs.
E) bonding of the anticodon to the codon and the attachment of amino acids to tRNAs.

Back 49

E) bonding of the anticodon to the codon and the attachment of amino acids to tRNAs.

Front 50

31) What is the function of GTP in translation?
A) GTP energizes the formation of the initiation complex, using initiation factors.
B) GTP hydrolyzes to provide phosphate groups for tRNA binding.
C) GTP hydrolyzes to provide energy for making peptide bonds.
D) GTP supplies phosphates and energy to make ATP from ADP.
E) GTP separates the small and large subunits of the ribosome at the stop codon.

Back 50

A) GTP energizes the formation of the initiation complex, using initiation factors.

Front 51

82) Which component is not directly involved in translation?
A) mRNA
B) DNA
C) tRNA
D) ribosomes
E) GTP

Back 51

B) DNA

Front 52

79) Which of the following is not true of a codon?
A) It consists of three nucleotides.
B) It may code for the same amino acid as another codon.
C) It never codes for more than one amino acid.
D) It extends from one end of a tRNA molecule.
E) It is the basic unit of the genetic code.

Back 52

D) It extends from one end of a tRNA molecule.

Front 53

78) 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.
E) DNA nucleases have isolated the transcription unit.

Back 53

B) several transcription factors have bound to the promoter.

Front 54

59) When the genome of a particular species is said to include 20,000 protein-coding regions, what does this imply?
A) There are 20,000 genes.
B) Each gene codes for one protein.
C) Any other regions are "junk" DNA.
D) There are also genes for RNAs other than mRNA.
E) The species is highly evolved.

Back 54

D) There are also genes for RNAs other than mRNA.

Front 55

58) In order for a eukaryotic gene to be engineered into a bacterial colony to be expressed, what must be included in addition to the coding exons of the gene?
A) the introns
B) eukaryotic polymerases
C) a bacterial promoter sequence
D) eukaryotic ribosomal subunits
E) eukaryotic tRNAs

Back 55

C) a bacterial promoter sequence

Front 56

57) In comparing DNA replication with RNA transcription in the same cell, which of the following is true only of replication?
A) It uses RNA polymerase.
B) It makes a new molecule from its 5' end to its 3' end.
C) The process is extremely fast once it is initiated.
D) The process occurs in the nucleus of a eukaryotic cell.
E) The entire template molecule is represented in the product.

Back 56

E) The entire template molecule is represented in the product.

Front 57

56) Which of the following is true of transcription in domain Archaea?
A) It is regulated in the same way as in domain Bacteria.
B) There is only one kind of RNA polymerase.
C) It is roughly simultaneous with translation.
D) Promoters are identical to those in domain Eukarya.
E) It terminates in a manner similar to bacteria.

Back 57

C) It is roughly simultaneous with translation.

Front 58

55) Gene expression in the domain Archaea in part resembles that of bacteria and in part that of the domain Eukarya. In which way is it most like the domain Eukarya?
A) Domain Archaea have numerous transcription factors.
B) Initiation of translation is like that of domain Eukarya.
C) There is only one RNA polymerase.
D) Transcription termination often involves attenuation.
E) Post-transcriptional splicing is like that of Eukarya.

Back 58

A) Domain Archaea have numerous transcription factors.

Front 59

54) Of the following, which is the most current description of a gene?
A) a unit of heredity that causes formation of a phenotypic characteristic
B) a DNA subunit that codes for a single complete protein
C) a DNA sequence that is expressed to form a functional product: either RNA or polypeptide
D) a DNA—RNA sequence combination that results in an enzymatic product
E) a discrete unit of hereditary information that consists of a sequence of amino acids

Back 59

C) a DNA sequence that is expressed to form a functional product: either RNA or polypeptide

Front 60

53) Which of the following statements is true about protein synthesis in prokaryotes?
A) Extensive RNA processing is required before prokaryotic transcripts can be translated.
B) Translation can begin while transcription is still in progress.
C) Prokaryotic cells have complicated mechanisms for targeting proteins to the appropriate cellular organelles.
D) Translation requires antibiotic activity.
E) Unlike eukaryotes, prokaryotes require no initiation or elongation factors.

Back 60

B) Translation can begin while transcription is still in progress.

Front 61

40) What is the function of the release factor (RF)?
A) It separates tRNA in the A site from the growing polypeptide.
B) It binds to the stop codon in the A site in place of a tRNA.
C) It releases the amino acid from its tRNA to allow the amino acid to form a peptide bond.
D) It supplies a source of energy for termination of translation.
E) It releases the ribosome from the ER to allow polypeptides into the cytosol.

Back 61

B) It binds to the stop codon in the A site in place of a tRNA.

Front 62

41) When the function of the newly made polypeptide is to be secreted from the cell where it has been made, what must occur?
A) It must be translated by a ribosome that remains free of attachment to the ER.
B) Its signal sequence must target it to the ER, from which it goes to the Golgi.
C) It has a signal sequence that must be cleaved off before it can enter the ER.
D) It has a signal sequence that targets it to the cell's plasma membrane where it causes exocytosis.
E) Its signal sequence causes it to be encased in a vesicle as soon as it is translated.

Back 62

B) Its signal sequence must target it to the ER, from which it goes to the Golgi.

Front 63

43) Why might a point mutation in DNA make a difference in the level of protein's activity?
A) It might result in a chromosomal translocation.
B) It might exchange one stop codon for another stop codon.
C) It might exchange one serine codon for a different serine codon.
D) It might substitute an amino acid in the active site.
E) It might substitute the N-terminus of the polypeptide for the C-terminus.

Back 63

D) It might substitute an amino acid in the active site.

Front 64

45) Which of the following types of mutation, resulting in an error in the mRNA just after the AUG start of translation, is likely to have the most serious effect on the polypeptide product?
A) a deletion of a codon
B) a deletion of two nucleotides
C) a substitution of the third nucleotide in an ACC codon
D) a substitution of the first nucleotide of a GGG codon
E) an insertion of a codon

Back 64

B) a deletion of two nucleotides

Front 65

2) How does a bacterial cell protect its own DNA from restriction enzymes?
A) by adding methyl groups to adenines and cytosines
B) by using DNA ligase to seal the bacterial DNA into a closed circle
C) by adding histones to protect the double-stranded DNA
D) by forming "sticky ends" of bacterial DNA to prevent the enzyme from attaching
E) by reinforcing the bacterial DNA structure with covalent phosphodiester bonds

Back 65

A) by adding methyl groups to adenines and cytosines

Front 66

4) A principal problem with inserting an unmodified mammalian gene into a BAC, and then getting that gene expressed in bacteria, is that
A) prokaryotes use a different genetic code from that of eukaryotes.
B) bacteria translate polycistronic messages only.
C) bacteria cannot remove eukaryotic introns.
D) bacterial RNA polymerase cannot make RNA complementary to mammalian DNA.
E) bacterial DNA is not found in a membrane-bounded nucleus and is therefore incompatible with mammalian DNA.

Back 66

C) bacteria cannot remove eukaryotic introns.

Front 67

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

Back 67

C) reverse transcriptase to reconstruct the gene from its mRNA.

Front 68

6) 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.
E) Only yeast cells allow the gene to be cloned.

Back 68

D) They are eukaryotic cells.

Front 69

7) The DNA fragments making up a genomic library are generally contained in
A) BACs.
B) recombinant viral RNA.
C) individual wells.
D) DNA-RNA hybrids.
E) radioactive eukaryotic cells.

Back 69

A) BACs.

Front 70

8) Yeast artificial chromosomes contain which of the following elements?
A) centromeres only
B) telomeres only
C) origin of replication only
D) centromeres and telomeres only
E) centromeres, telomeres, and an origin of replication

Back 70

E) centromeres, telomeres, and an origin of replication

Front 71

10) A researcher needs to clone a sequence of part of a eukaryotic genome in order to express the sequence and to modify the polypeptide product. She would be able to satisfy these requirements by using which of the following vectors?
A) a bacterial plasmid
B) BAC to accommodate the size of the sequence
C) a modified bacteriophage
D) a human chromosome
E) a YAC with appropriate cellular enzymes

Back 71

E) a YAC with appropriate cellular enzymes

Front 72

19) The reason for using Taq polymerase for PCR is that
A) it is heat stable and can withstand the temperature changes of the cycler.
B) only minute amounts are needed for each cycle of PCR.
C) it binds more readily than other polymerases to primer.
D) it has regions that are complementary to primers.
E) All of these are correct.

Back 72

A) it is heat stable and can withstand the temperature changes of the cycler.

Front 73

20) Why might a laboratory be using dideoxy nucleotides?
A) to separate DNA fragments
B) to clone the breakpoints of cut DNA
C) to produce cDNA from mRNA
D) to sequence a DNA fragment
E) to visualize DNA expression

Back 73

D) to sequence a DNA fragment

Front 74

23) DNA fragments from a gel are transferred to a nitrocellulose paper during the procedure called Southern blotting. What is the purpose of transferring the DNA from a gel to a nitrocellulose paper?
A) to attach the DNA fragments to a permanent substrate
B) to separate the two complementary DNA strands
C) to transfer only the DNA that is of interest
D) to prepare the DNA for digestion with restriction enzymes
E) to separate out the PCRs

Back 74

A) to attach the DNA fragments to a permanent substrate

Front 75

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

Back 75

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

Front 76

25) Which of the following describes the transfer of polypeptide sequences to a membrane to analyze gene expression?
A) Southern blotting
B) Northern blotting
C) Western blotting
D) Eastern blotting
E) RT-PCR

Back 76

C) Western blotting

Front 77

26) Which of the following uses reverse transcriptase to make cDNA followed by amplification?
A) Southern blotting
B) Northern blotting
C) Western blotting
D) Eastern blotting
E) RT-PCR

Back 77

E) RT-PCR

Front 78

33) Which of the following is most closely identical to the formation of twins?
A) cell cloning
B) therapeutic cloning
C) use of adult stem cells
D) embryo transfer
E) organismal cloning

Back 78

E) organismal cloning

Front 79

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

Back 79

D) fusion of an adult cell's nucleus with an enucleated sheep egg, followed by incubation in a surrogate

Front 80

35) Which of the following problems with animal cloning might result in premature death of the clones?
A) use of pluripotent instead of totipotent stem cells
B) use of nuclear DNA as well as mtDNA
C) abnormal regulation due to variant methylation
D) the indefinite replication of totipotent stem cells
E) abnormal immune function due to bone marrow dysfunction

Back 80

C) abnormal regulation due to variant methylation

Front 81

38) A researcher is using adult stem cells and comparing them to other adult cells from the same tissue. Which of the following is a likely finding?
A) The cells from the two sources exhibit different patterns of DNA methylation.
B) Adult stem cells have more DNA nucleotides than their counterparts.
C) The two kinds of cells have virtually identical gene expression patterns in microarrays.
D) The nonstem cells have fewer repressed genes.
E) The nonstem cells have lost the promoters for more genes.

Back 81

A) The cells from the two sources exhibit different patterns of DNA methylation.

Front 82

39) 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 nonfertilized eggs.
D) Therapeutic cloning supplies cells for repair of diseased or injured organs.

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

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44) Genetically engineered plants
A) are more difficult to engineer than animals.
B) include a transgenic rice plant that can help prevent vitamin A deficiency.
C) are being rapidly developed, but traditional plant breeding programs are still the only method used to develop new plants.
D) are able to fix nitrogen themselves.
E) are banned throughout the world.

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B) include a transgenic rice plant that can help prevent vitamin A deficiency.