Deck 20: The Molecular Revolution: Biotechnology and Beyond

Question 1

If mRNAs could be ligated and replicated within plasmids, what enzyme commonly used in recombinant DNA technology would no longer be needed?

A) Taq polymerase
B) restriction enzymes
C) reverse transcriptase
D) DNA polymerase

Answer 1

C

Question 2

In early forensic applications of DNA fingerprinting, DNA was extracted from crime scene material, digested with restriction enzymes, and then analyzed. Today, PCR is used in the early steps of forensic DNA analysis. What advantage does PCR provide over the former method?

A) PCR produces many more bands for fingerprint analysis, making it a more informative technique.
B) PCR can analyze DNA, proteins, and carbohydrates, whereas restriction enzyme analysis is limited to DNA.
C) PCR can cut DNA at many more sites than restriction enzymes can.
D) PCR requires much less DNA for analysis.

Answer 2

D

Question 3

Which of the following is a gene library?

A) a collection of PCR- amplified DNAs
B) a collection of different DNA fragments ligated into plasmids
C) a collection of genes that have been sequenced from a particular organism
D) a collection of DNAs cut by a restriction enzyme
E) a collection of plasmids cut by a restriction enzyme

Answer 3

B

Question 4

When constructing a cDNA library from a particular organism, the choice of tissue is , whereas when constructing a genomic DNA library from the same organism, the choice of tissue is .

A) immaterial; immaterial
B) critical; immaterial
C) critical; critical
D) immaterial; critical

Question 5

In a single PCR cycle consisting of 15 seconds at 94°C, 30 seconds at 50°C, and 1 min at 72°C, what is happening in the step run at 50°C?

A) DNA polymerase is being inactivated.
B) DNA polymerase is extending new DNA from the primers.
C) Primers are being denatured.
D) Primers are annealing to the DNA to be amplified.
E) The DNA to be amplified is being denatured.

Question 6

Plasmids are used as cloning vectors in genetic engineering. This means that plasmids allow for

A) carrying of RNA into a cell and RNA replication.
B) infection of cells.
C) carrying of DNA into a cell and DNA replication.
D) DNA replication outside rather than inside cells.

Question 7

What information is critical to the success of PCR itself?

A) The complete DNA sequence of the DNA to be amplified must be known.
B) 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.
C) The DNA sequence of the ends of the DNA to be amplified must be known.
D) The sequence of restriction enzyme recognition sites in the DNA to be amplified must be known.

Question 8

In the current form of dideoxy DNA sequencing, the primer is unlabeled and each dideoxynucleotide is labeled with a different fluorescent marker. This method

A) eliminates the need to run sequencing reaction products on a gel.
B) eliminates the need for sophisticated machines to read the output of each sequencing reaction.
C) allows a DNA sequence to be determined from 4 separate sequencing reactions, each run on a separate lane of a gel.
D) allows a DNA sequence to be determined from one sequencing reaction that is run on a single lane of a gel.

Question 9

Many identical copies of genes cloned in bacteria are produced as a result of

A) plasmid replication.
B) bacterial cell replication.
C) Southern blotting.
D) A and B.
E) all of the above.

Question 10

What is one drawback of next- generation sequencing?

A) Next- generation sequencing works best on eukaryotic DNA.
B) Next- generation sequencing can only be used to sequence whole genomes.
C) Next- generation sequencing is slower than Sanger sequencing.
D) Next- generation sequencing has difficulty sequencing DNA with repetitive sequence.
E) Next- generation sequencing is more expensive than Sanger sequencing.

Question 11

The general term for the manipulation of organisms to create products or cure disease is

A) recombinant DNA technology.
B) biotechnology.
C) plasmid- mediated transformation.
D) gene cloning.

Question 12

How does a gene library differ from a gene clone?

A) A gene library is a much shorter DNA sequence than a gene clone.
B) A gene library contains many different cloned DNA sequences; a gene clone contains one type of DNA sequence.
C) A gene library is sequence information stored in a computerized database; a gene clone is an actual sequence of DNA.
D) A gene library contains one type of cloned DNA sequence; a gene clone contains many different DNA sequences.
E) A gene library is a much longer DNA sequence than a gene clone.

Question 13

What characteristic of short tandem repeats STRs) DNA makes it useful for DNA fingerprinting?

A) The sequence of DNA that is repeated varies significantly from individual to individual.
B) The sequence variation is acted upon differently by natural selection in different environments.
C) Each short tandem repeat sequence variation binds a different protein.
D) The number of repeats varies widely from person to person or animal to animal.
E) Every racial and ethnic group has inherited different short tandem repeats.

Question 14

Imagine that you've isolated the complete human growth hormone gene directly from the human genome. After running through all the steps described in Chapter 20 for cloning and gene expression in bacteria, you find that no human growth hormone is expressed. What is the most likely explanation?

A) Human DNA cannot be cloned in a bacterium.
B) Human DNA can be maintained in cloned form only for brief periods in bacteria.
C) Bacteria cannot carry out splicing.
D) Bacteria cannot translate human mRNA coding sequences.
E) Bacteria lack a nucleus for proper transcription of eukaryotic genes.

Question 15

Which of the following is in the correct order for one cycle of PCR?

A) Anneal primers; denature DNA; extend primers.
B) Add fresh enzyme; denature DNA; anneal primers; add dNTPs; extend primers.
C) Denature DNA; anneal primers; extend primers.
D) Extend primers; anneal primers; denature DNA.
E) Denature DNA; add fresh enzyme; anneal primers; add dNTPs; extend primers.

Question 16

What does bioinformatics include?
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) II and IV
B) I, III, and IV
C) I and II
D) I, II, III, and IV
E) II and III

Question 17

A bacterial cell that has taken up plasmid DNA is

A) a library.
B) ligated.
C) transformed.
D) a vector.
E) a cDNA.

Question 18

The restriction enzymes BamHI and BclI cut at the points indicated by arrows:

If one sample of DNA was cut with BamHI and another with BclI, and these two samples were mixed and treate DNA ligase, what would occur?

A) No DNAs would be ligated joined together).
B) Only the BamHI- cut DNA would be ligated.
C) Only the BclI- cut DNA would be ligated.
D) Both BamHI- cut and BclI- cut DNAs would be ligated, but only to DNA fragments cut with the same enzyme e.g., BamHI fragments would be ligated only to other BamHI fragments).
E) Both BamHI- cut and BclI- cut DNAs would be ligated with no preference for which fragment is ligated to which other.

Question 19

The final step in a DNA sequencing reaction is to run the DNA fragments on a gel. What purpose does this serve?

A) It terminates the sequencing reaction at particular bases.
B) It provides the substrate for DNA polymerase.
C) It separates dideoxynucleotides from deoxynucleotides.
D) It separates DNA fragments generated during the sequencing reaction based on one- nucleotide differences in their size.

Question 20

Since dideoxy sequencing is based on the chain termination, why are normal deoxynucleotides also included in the reaction?

A) to produce a range of DNA synthesis products that terminate at every occurrence of a particular base
B) to provide a substrate for DNA polymerase
C) to create DNA synthesis products long enough to allow running a gel
D) to enhance the chain termination ability of the deoxynucleotides

Question 21

Which type of disorder is most difficult to correct by gene therapy?

A) a recessive disorder
B) an incompletely dominant disorder
C) a dominant disorder
D) Disorders showing all these forms of dominance present equal challenges.

Question 22

Gene therapy requires

A) knowledge and availability of the wild- type allele of the defective gene.
B) an ability to introduce the wild- type allele into the patient.
C) an ability to express the introduced gene at the correct level, time, and site within the patient.
D) A and B.
E) all of the above.

Question 23

You ask your student to transfer a plasmid- free bacterial strain to multiple small tubes for long term storage. A short while later, your student admits that he did not use a clean sterile pipette to transfer the bacteria to the small tubes, but rather grabbed the same pipette he had just used to collect newly transformed bacteria. Why would this pose a problem?

A) Plasmids will incorporate into the chromosomal DNA.
B) Plasmid can contain genes that confer antibiotic resistance.
C) Plasmids can be transferred between bacteria via pili.
D) Newly transformed bacteria will actively undergo binary fission.

Question 24

What can proteomics reveal that genomics cannot?

A) the patterns of alternative splicing
B) the number of genes characteristic of a species
C) the movement of transposable elements within the genome
D) the levels of mRNAs present in a particular cell type
E) the set of proteins present within a cell or tissue type

Question 25

In nature, what is the major mechanism of introducing new genes into eukaryotic genomes?

A) unequal crossing over at microsatellite repeats
B) pseudogene creation
C) transfer from viruses
D) pseudogene restoration
E) duplication followed by evolutionary divergence

Question 26

Use the following information when answering the corresponding questions).
A study by Krings et al. investigated Neanderthal DNA by amplifying 30 000- year- old samples and sequencing it. M. Krings Stone, R.W. Schmitz, H. Krainitzki, M. Stoneking, and S. Pääbo. 1997. Neandertal DNA sequences and the origin of modern humans. Cell 90:19- 30).
Here is part of the lead paragraph in the "Methods" section of the Krings et al. paper:
Protective clothing was worn throughout the sampling procedure. Instruments used were treated with 1 M HCl followed by e rinsing in distilled water. After removal, the sample was immediately put into a sterile tube for transport to Munich. All subse manipulations of the sample, and experimental procedures prior to cycling of PCR reactions, were carried out in laboratories dedicated to the analysis of archaeological specimens, where protective clothing, separate equipment and reagents, UV irradia other measures to...
A concluding paragraph of the Krings et al. paper states:
It must be emphasized that the above conclusions are based on a single individual sequence; the retrieval and analysis of mtD sequences from additional Neanderthal specimens is obviously desirable. If this proves possible, then the potential exists to address several questions concerning Neanderthals that hitherto could be studied exclusively by morphological and archaeological approaches. For example, the genetic relationship between Neanderthal populations in Europe and in western Asia could be explored, as could the demographic history of Neanderthal populations.
Why did the researchers wear protective clothing and note so emphatically that they did so?

A) They needed to minimize the chance of introducing their own mitochondrial DNA to the sample.
B) They needed to be certain there were no ancient pathogens on the sample that modern humans hadn't been exposed to.
C) They needed to be sure not to harm the precious sample with oils from skin or moisture from their breath.
D) Because the work was done in Germany, they needed to follow stringent, standard German laboratory procedures and document their compliance.

Question 27

Unequal crossing over during prophase I can result in one sister chromosome with a deletion and another with a duplication. A mutated form of hemoglobin, so- called hemoglobin Lepore, exists in the human population. Hemoglobin Lepore has a deleted series of amino acids. If this mutated form was caused by unequal crossing over, what would be an expected consequence?

A) Each of the genes in the hemoglobin gene family must show the same deletion.
B) The deleted gene must have undergone exon shuffling.
C) If it is still maintained in the human population, hemoglobin Lepore must be selected for in evolution.
D) The deleted region must be located in a different area of the individual's genome.
E) There should also be persons whose hemoglobin contains two copies of the series of amino acids that is deleted in hemoglobin Lepore.

Question 28

Imagine that you compare two DNA sequences found in the same location on homologous chromosomes. On one of the homologs, the sequence is AACTACGA. On the other homolog, the sequence is AACTTCGA. Within a population, you discover that each of these sequences is common. These sequences

A) identify a protein- coding region of a gene.
B) cause disease.
C) protect against disease.
D) contain a SNP that may be useful for genetic mapping.
E) none of the above.

Question 29

Imagine that you are searching for the gene associated with nail- patella syndrome, a dominant genetic disorder that causes developmental abnormalities. In a large pedigree, you discover an association between nail- patella syndrome and a genetic marker that occurs in two different alleles, A and B. Fifteen individuals within this pedigree have nail- patella syndrome and are A/B heterozygotes for the marker. Thirty individuals within this pedigree don't suffer from nail- patella syndrome and are homozygous for the A marker allele. One individual within this pedigree has nail- patella syndrome and is also homozygous for the A marker allele. The most likely explanation for this exceptional individual is

A) recombination occurred between the nail- patella gene and marker gene in one of the parents of the exceptional individual.
B) a new mutation converted the B allele of the marker to the A form.
C) a new mutation converted the disease- causing allele to the wild- type form.
D) the exceptional nail- patella individual is haploid.

Question 30

Name two examples of lateral gene transfer to eukaryotes that involve cellular organelles.

A) transfer of the bacterial spindle apparatus to form ribosomes and transfer RNAs
B) transfer of bacterial genes that were predecessors to mitochondria and chloroplasts
C) transfer of bacterial chloroplasts to form nuclei and ribosomes
D) transfer of the bacterial mitochondrial apparatus to form nuclei and ribosomes
E) transfer of bacterial genes to form nuclei and the mitotic spindle apparatus

Question 31

Proteomics is defined as the

A) study of the full protein set encoded by a genome.
B) study of how amino acids are ordered in a protein.
C) linkage of each gene to a particular protein.
D) study of how a single gene activates many proteins.
E) totality of the functional possibilities of a single protein.

Question 32

Use the following information when answering the corresponding questions).
A study by Krings et al. investigated Neanderthal DNA by amplifying 30 000- year- old samples and sequencing it. M. Krings Stone, R.W. Schmitz, H. Krainitzki, M. Stoneking, and S. Pääbo. 1997. Neandertal DNA sequences and the origin of modern humans. Cell 90:19- 30).
Here is part of the lead paragraph in the "Methods" section of the Krings et al. paper:
Protective clothing was worn throughout the sampling procedure. Instruments used were treated with 1 M HCl followed by e rinsing in distilled water. After removal, the sample was immediately put into a sterile tube for transport to Munich. All subse manipulations of the sample, and experimental procedures prior to cycling of PCR reactions, were carried out in laboratories dedicated to the analysis of archaeological specimens, where protective clothing, separate equipment and reagents, UV irradia other measures to...
A concluding paragraph of the Krings et al. paper states:
It must be emphasized that the above conclusions are based on a single individual sequence; the retrieval and analysis of mtD sequences from additional Neanderthal specimens is obviously desirable. If this proves possible, then the potential exists to address several questions concerning Neanderthals that hitherto could be studied exclusively by morphological and archaeological approaches. For example, the genetic relationship between Neanderthal populations in Europe and in western Asia could be explored, as could the demographic history of Neanderthal populations.
How could the "demographic history of Neanderthal populations" be explored if mitochondrial DNA from other Neanderthal samples could be PCR amplified?

A) These Neanderthal sequences could be compared to each other to see how much they differ; the more they differ, the greater the divergence between these populations.
B) In the attempt to amplify other Neanderthal DNAs, those that amplify must be from more modern populations and those that don't are from more ancient populations.
C) These Neanderthal sequences could be compared to those of modern humans to learn if they are closely related.
D) These Neanderthal sequences could be compared to those of modern humans; the more they differ, the more distant the time of divergence between the Neanderthal and modern human lineages.

Question 33

What would happen if alternative splicing did not occur?

A) The E. coli genome would contain many fewer genes.
B) There would be little correlation between the complexity of organisms and genome size.
C) There would be many fewer genes devoted to metabolism in Arabidopsis and yeast.
D) The human genome would likely contain many more genes.
E) Fewer mutations would occur in a human cell's lifespan.

Question 34

Which of the following questions is asked in functional genomics research?

A) What is the number of Drosophila genes?
B) How closely related are the visual pigment genes of mouse and human?
C) How does the G- C content of human DNA vary across the genome?
D) What is the pattern of gene expression during mouse development?
E) How many introns exist in the human CFTR gene?

Question 35

To create a viral vector for delivery of genes into mammalian cells, the virus must be engineered to

A) remove all viral genes, replacing them with the mammalian genes to be delivered.
B) remove viral genes involved with virus replication and add mammalian genes to be delivered.
C) remove the viral genome and coat proteins and replace them with recombinant plasmids carrying the mammalian genes to be delivered.
D) remove viral coat proteins.

Question 36

Transgenic mice

A) were instrumental in pinpointing the location of the huntingtin gene.
B) often provide valuable animal models of human disease.
C) are essential for mapping human genes.
D) are now used in place of bacteria for cloning human genes.

Question 37

What is a gene family is composed of?

A) multiple genes whose products must be coordinately expressed
B) a highly conserved gene found in a number of different species
C) many tandem repeats such as those found in centromeres and telomeres
D) a gene whose exons can be spliced in a number of different ways
E) genes whose sequences are very similar and that probably arose by duplication

Question 38

The comparison between the number of human genes and those of other animal species has led to many conclusions, including which of the following?

A) The number of proteins expressed by the human genome is far more than the number of its genes.
B) More than half of the human genome is composed of genes that are transcribed and then translated into protein.
C) The density of the human genome is far higher than in most other animals.
D) The genomes of most other organisms are significantly smaller than the human genome.
E) Most human DNA consists of genes for protein, tRNA, rRNA, and miRNA.

Question 39

Why is it essential that genetic markers used in mapping disease genes be polymorphic?

A) If the marker isn't polymorphic, its position cannot be known.
B) If the marker isn't polymorphic, then it's impossible to use genetic mapping techniques to establish an association between the marker and the disease gene.
C) If the marker isn't polymorphic, it cannot be physically linked to a gene associated with human disease.
D) If the marker isn't polymorphic, then it will not be inherited in any predictable manner.