Chapter 22: Biotechnology (Test 4)
A person is heterozygous for a locus on Chromosome 1. The first copy of Chromosome 1 has the sequence 5′-AACTACGA-3′; the second copy has the sequence 5′-AACTTCGA-3′. Which of the following statements correctly describes theses sequences? A) They contain a SNP that may be useful for genetic mapping. B) They identify a location where only one copy could be cut by a restriction enzyme. C) They contain an STR that may be useful for forensic analysis. D) They may carry out RNA interference.
A
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
A
Use the following information to answer the question. A piece of DNA was incubated with a restriction enzyme called Hind III. The restriction enzyme digestion produced eight different size fragments that were separated by gel electrophoresis. Which of the following observations correctly describes characteristics of the outcomes of this process? A) When separated by gel electrophoresis, the pattern of DNA bands specific to Hind III digestion; repeating the process using a different restriction enzyme would not produce these fragments. B) The sequence that Hind III binds is found at places in this piece of DNA; gel electrophoresis provides the force needed to break the DNA under the DNA-enzyme complexes. C) If an electrical current is not used during gel electrophoresis, eight separate DNA bands would be visible, but they would not be separated as much as when an electrical current is used. D) Because restriction enzymes cut specific sequences of DNA, use of any other different restriction enzyme would result in one large piece of DNA rather than eight fragments.
A
What information is critical to the success of polymerase chain reaction (PCR)? A) The DNA sequence of the ends of the DNA 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.
A
When attempting to introduce a particular fragment of DNA into the genome of an animal cell which of the following methods would be most successful? A) CRISPR/Cas9 recombination B) in vitro hybridization of the DNA with the cell's genome C) infecting the mouse cell with a Ti plasmid D) RNA-seq followed by genetic profiling
A
Which of the following characteristics of RNA-seq make it particularly suitable to use in genome-wide expression studies? A) It does not require knowledge of the genome's sequence before the study begins. B) The primers used are at least 15 nucleotides long, and therefore provide high specificity. C) It measures levels of expression over a narrow, well-characterized range. D) The process results in cDNA fragments that can be used to reassemble plasmids containing the genome.
A
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) It is isolated from bacteria so there is a large supply. C) It binds more readily than other polymerases to the primers. D) It has regions that are complementary to the primers.
A
Which of the following characteristics of short tandem repeats (STRs) DNA makes it useful for DNA fingerprinting (genetic profiling)? A) The number of repeats at a particular STR is inherited following Mendelian genetic patterns. B) The specific sequence of DNA that is repeated varies significantly from individual to individual. C) Knowing the number of repeats that a person has at a single chromosomal locus is sufficient to connect that person to a DNA sample from a crime scene. D) Analysis by RT-PCR allows the profile to be produced even when the sample is in poor condition.
A
Which of the following describes a concern that has been raised regarding the use of transgenic plants to produce human proteins, like growth hormones or insulin? A) Plant allergens could contaminate samples of the human proteins produced. B) Insects consuming the plants would incorporate the genes and develop human characteristics. C) Harvesting the plants within research facilities would result in habitat destruction. D) The human digestive system cannot digest plant cell wall components so the component would not be accessible
A
Which of the following measures has been adopted by researchers to address concerns over the safety of using DNA technology? A) Microorganisms used in recombinant DNA experiments must be modified to ensure that they cannot survive outside of the laboratory. B) Genetically modified organisms are not allowed to be part of our food supply. C) Transgenic plants are engineered so that the plant genes cannot hybridize. D) Experiments involving HIV or other potentially dangerous viruses have been banned.
A
Which of the following outcomes could be achieved using RNAi methodology? A) reduction in protein produced from a gene of interest B) removal of an allele in a homozygous individual C) addition of a new intron within a specific RNA sequence D) increased cytoplasmic concentration of a desired protein
A
Which of the following processes helps bacterial cells protect their own DNA from restriction enzymes (endonucleases)? A) adding methyl groups to adenines and cytosines B) using DNA ligase to seal the bacterial DNA into a closed circle C) adding histones to protect the double-stranded DNA D) forming "sticky ends" of bacterial DNA to prevent the enzyme (endonuclease) from attaching
A
Which of the following processes is used to convert adult cells into pluripotent stem cells (iPS). A) A retrovirus is used to introduce four specific master regulatory genes. B) The adult stem cells are 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.
A
Which of the following statements correctly describes characteristics of adult stem cells and other cells isolated from the same tissue at the same time? A) The two cell types have different patterns of DNA methylation. B) The adult stem cells have different DNA than the non-stem cells. C) The two kinds of cells have virtually identical gene expression patterns in microarrays. D) The non-stem cells have fewer repressed genes than the adult stem cells
A
A 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
B
Being able to amplify specific DNA fragments is critical our ability to study genes because ________. A) before amplification, DNA fragments are likely to bind to RNA and would no longer be able to be analyzed B) a gene may represent only a millionth of the cell's DNA C) restriction enzymes (endonucleases) cut DNA into fragments that are too small D) making a clone requires multiple copies of each gene per clone
B
Gene therapy requires the ability to do which of the following? A) isolate the defective chromosome within the nuclei of the patient's cells B) introduce the normal allele into the patient C) express the introduced gene at any time within the patient D) remove the vector used to introduce the non-defective allele
B
In large-scale, genome-wide association studies in humans, which of the following types of genetic markers are typically sought by researchers? A) SNPs found approximately 100-300 bases apart within the genome B) specific SNPs found more often in persons with a particular disorder than in healthy controls C) specific SNPs inherited more frequently by members within a family than by unrelated individuals D) SNPs where one allele is found in two or more adjacent genes
B
PCR and cellular DNA replication share which of the following characteristics? A) require a DNA primer to begin extension B) extend new strand in 5 to 3 direction C) form short Okazaki fragments D) require helicase to separate DNA template strands
B
Reproductive cloning of human embryos is generally considered unethical. However, on the subject of therapeutic cloning, there is a wider divergence of opinion. Which of the following statements provides the best argument in support of therapeutic cloning? A) The use of adult stem cells is likely to produce more cell types than the use of embryonic stem cells. B) Cloning to produce embryonic stem cells may lead to great medical benefits for many. C) Cloning to produce stem cells relies on a different initial procedure than reproductive cloning. D) A clone that lives until the blastocyst stage does not yet have human DNA.
B
Which of the following describes the best approach to making a gene that contains introns shorter, but remaining functional, for genetic engineering purposes? A) express in bacteria then a restriction enzyme (endonuclease) to cut the gene into shorter pieces B) isolate the specific mRNA from the animal then use reverse transcriptase to produce cDNA C) isolate the specific protein from the animal then use the genetic code to reconstruct DNA from the polypeptide sequence D) using DNA ligase to put together fragments of the DNA that code for a particular polypeptide
B
Which of the following is an ethical question regarding the use of CRISPR-Cas9 gene editing in humans? A) Should we be able to reduce the prevalence of human disease? B) Should we be able to select and control the genetic makeup of the human population? C) Should we be able to use try to use approaches developed in other model systems (for example, fruit flies, mice) in humans? D) Should we be able to determine information about individuals' genomes?
B
Which of the following processes uses labeled probes to visualize the expression of genes in whole tissues and organisms? A) RT-PCR B) in situ hybridization C) DNA microarrays D) RNA interference
B
Which of the following sequences in double-stranded DNA is most likely to be recognized as a cutting site for a restriction enzyme? A) AAGG TTCC B) GGCC CCGG C) ACCA TGGT D) AAAA TTTT
B
Which of the following sequences is most likely to be cut by a restriction endonuclease? A) 5' - AATTCT 3' 3' -TTAAGA-5' B) 5' -AATATT-3' 3' -TTATAA-5' C) 5' -AAAATT-3' 3' -TTTTAA-5' D) 5' -ACTACT-3' 3' -TGATGA-5'
B
Which of the following statements correctly describes a characteristic of genetically engineered plants? A) The modification makes new plants infertile and unable to reproduce without grafting. B) The alterations can be made in a somatic cell then grown into a whole plant with new traits. C) Genetically engineered plants are used in research but not yet in commercial agricultural production. D) Genetically engineered plants are banned throughout the world.
B
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) Embryonic stem cells are used to provide cells for repair of diseased tissue, and adult stem cells are not.
B
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
B
Which order of the following steps provides the most logical sequence to follow when splicing foreign DNA into a plasmid and inserting the plasmid into a bacterium? I. Transform bacteria with a recombinant DNA molecule. II. Cut the plasmid DNA using restriction enzymes (endonucleases). III. Extract plasmid DNA from bacterial cells. IV. Hydrogen-bond the plasmid DNA to non-plasmid DNA fragments. V. Use ligase to seal plasmid DNA to non-plasmid DNA. A) II, III, V, IV, I B) III, II, IV, V, I C) III, IV, V, I, II D) IV, V, I, II, III
B
Animal cloning may result in premature death of the clones due to which of the following problems? A) use of pluripotent instead of totipotent stem cells B) use of nuclear DNA as well as mtDNA C) abnormal gene regulation due to variant methylation D) the indefinite replication of totipotent stem cells
C
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
C
If a researcher is examining cells from a breast tumor biopsy which of the following microarray assay (DNA chip) outcomes would best support a diagnosis that the tumor is cancerous? A) a mitochondrial encoded gene shows significantly higher expression in these cells than in liver cells B) the pattern of fluorescence indicates some cells are undergoing mitosis. C) the expression pattern in these cells differs from the pattern in non-tumor breast tissue D) a group of cDNAs expression matches those in colon cancer samples from the same population
C
One predicted aspect of climate change is that levels of precipitation and temperature will become more variable. Given this information, which of the following describes the best strategy for genetically engineering crops? A) Genetically engineer crops so that the component used for food has the longest possible shelf life. B) Genetically engineer most crops to withstand very long droughts. C) Genetically engineer individuals with different phenotypes within a single crop type. D) Genetically engineer crops to grow and mature as quickly as possible.
C
Pax-6 is a gene involved in eye formation that has homologues in invertebrates and vertebrates. The fact that expressing the mouse form of Pax-6 in a fruit fly leads to a compound fly eye (not a single lens mouse eye) suggests which of the following characteristics of this gene? A) Pax-6 genes are identical in nucleotide sequence. B) PAX-6 proteins have identical amino acid sequences. C) Pax-6 gene is highly conserved and shows shared evolutionary ancestry. D) PAX-6 proteins are different for formation of different kinds of eyes.
C
Plants are more readily manipulated by genetic engineering than are animals because ________. A) plant genes do not contain introns B) more vectors are available for transferring recombinant DNA into plant cells C) a somatic plant cell can often give rise to a complete plant D) plant cells have larger nuclei
C
The cloning of Dolly the sheep is an example of which of the following processes? 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 sheep C) transfer of an adult cell's nucleus into an enucleated sheep egg, followed by incubation in a surrogate D) isolation of stem cells from a lamb embryo and production of a zygote equivalent
C
Which of the following best explains the inability of bacteria to correctly express the protein products of plasmid containing an unmodified mammalian gene? A) prokaryotes use a different genetic code from that of eukaryotes B) bacteria translate only mRNAs that have multiple messages C) bacteria cannot remove eukaryotic introns D) bacterial RNA polymerase cannot make RNA complementary to mammalian DNA
C
Which of the following characteristics of retroviruses most directly contributes to their usefulness in gene therapy applications? A) After infection, the RNA genome of retroviruses is short lived. B) Retroviruses possess reverse transcriptase. C) DNA copies of retroviral genomes become integrated into the genome of the infected cell. D) Conversion of a retrovirus' genome from RNA to DNA occurs without significant proofreading.
C
Which of the following describes how DNA microarrays have helped advance 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.
C
Which of the following is true of cDNA produced using human brain tissue as the starting material? A) The procedure to make it requires amplification by the polymerase chain reaction. B) It is 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 includes the introns of the pre-mRNA.
C
Which of the following reasons best explains why sequencing an entire genome, such as that of C. elegans, a nematode, is 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 vertebrates.
C
Which of the following statements correctly describes how RNA interference (RNAi) reduces the expression of selected genes? A) Synthetic double-stranded RNA molecules stop transcription from occurring. B) Synthetic single-stranded RNA molecules trigger incorrect processing of pre-RNA into RNA. C) Synthetic double-stranded RNA molecules trigger the breakdown of a gene's messenger RNA. D) Synthetic single-stranded RNA molecules bind cellular RNA and block translation.
C
Which of the following statements describes a technical barrier to using gene therapy in humans? A) Human cells do take up or incorporate foreign DNA into their genomes. B) Cells with transferred genes are unlikely to replicate. C) The expression of transferred genes may not be appropriately controlled. D) mRNA from transferred genes cannot be translated.
C
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
D
In animals, what is the difference between reproductive cloning and therapeutic cloning? A) Only reproductive cloning uses totipotent cells. B) Only reproductive cloning uses embryonic stem cells. C) Only therapeutic cloning uses nuclei of adult cells transplanted into enucleated unfertilized eggs. D) Only therapeutic cloning supplies cells for repair of diseased or injured organs.
D
In the form of gene therapy used successfully for severe combined immunodeficiency syndrome, SCID-X1, how is the genetic engineering of human cells achieved? A) by injecting engineered viruses into the patient's bloodstream B) by injecting engineered viruses into the patient's bone marrow C) by treating a relative's cultured bone marrow cells with genetically engineered viruses and then injecting these cells into the patient's bone marrow D) by isolating the patient's bone marrow cells, infecting them with genetically engineered viruses, and injecting them back into the patient's bone marrow
D
Many identical copies of genes cloned in bacteria are produced as a result of which of the following processes? A) plasmid replication only B) bacterial cell reproduction only C) transformation D) plasmid and bacterial cell reproduction
D
The first cloned cat, called Carbon Copy, was a calico, but she looked significantly different from her female parent. Which of the following best explains the reason for the differences? A) The cloning was done poorly and some contaminating cat DNA became part of Carbon Copy's genome. B) Fur color genes in cats are determined by differential acetylation patterns that reset when cloned. C) Cloned animals have been found to have a higher frequency of transposon activation. D) X chromosome inactivation in the embryo is random and produces different patterns.
D
Which of the following best describes a biological concern regarding the use of CRISPRCas9 gene editing in humans? A) The process may introduce viral sequences into the human genome leading to unwanted blood cell proliferation (leukemia). B) The presence of repeated sequences (STRs) within the human genome mean that the editing cannot be targeted to a specific location. C) The process was first discovered in bacteria and human cells cannot correctly interpret prokaryotic regulatory signals. D) The modifications created by the process may result in unintended effects on non-target genes.
D
Which of the following characteristics best support using yeast cells instead of bacterial cells to express mammalian proteins via cloning? A) They easily form colonies. B) They can grow on solid or liquid media. C) They do not have plasmids. D) They are eukaryotic cells.
D
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
D
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
D
Which of the following statements best explain why retroviral vectors for gene therapy may increase the patient's risk of developing cancer? A) Retroviral vectors introduce proteins from the virus that alters control of the host cell's cell cycle. B) Retroviral vectors do not express the genes that were introduced into a patient's cells. C) Activating transcription of the retroviral vector's genes may result in spread of the virus throughout the body. D) Integration of the retroviral vector's DNA into the genome may misregulate the expression of genes near the integration site.
D