HBIO CH 12 DNA TECHNOLOGY AND GENOMICS PRACTICE TEST – Flashcards
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Which of the following enzymes can create a bond between adjacent, unjoined nucleotides?
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DNA ligase
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Frequently, genetic engineers use plasmids, which are _____.
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small circlets of DNA found in bacteria
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What is gene cloning?
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Gene cloning occurs when a bacterium carrying a recombinant plasmid reproduces, thus allowing for the production of multiple copies of the recombinant plasmid.
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"Sticky ends" are very useful in genetic engineering because they _____.
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provide a site for complementary base pairing so that pieces of DNA can be linked together
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An enzyme that "cuts" DNA at a specific sequence of nucleotide bases is called _____.
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a restriction enzyme
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The "normal" function of restriction enzymes is to _____.
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destroy foreign DNA
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The recombinant molecule below was generated using which two enzymes?
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a restriction enzyme and a ligase
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Shown below is the effect of a restriction enzyme known as EcoRI. Cutting with this enzyme allows scientists to _____.
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insert a foreign piece of DNA cut with the same restriction enzyme
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What does the term sticky end refer to in genetic engineering?
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the generation of short fragments of single-stranded DNA left at the end of a DNA molecule
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When a typical restriction enzyme cuts a DNA molecule, the cuts are staggered so that the DNA fragments have single-stranded ends. This is important in recombinant DNA technology because _____.
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the fragments will bond to other fragments with complementary single-stranded ends
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The so-called sticky ends of a plasmid or bacterial chromosome are _____.
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unpaired bases produced by a restriction enzyme
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DNA used in recombinant DNA techniques is first cut into fragments by _____.
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restriction enzymes
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What does the term vector refer to in genetic engineering?
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a plasmid or other agent used to transfer DNA into a living cell
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Copies of cloned genes are stored in a _____.
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genomic library
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Bacteria lack RNA-splicing machinery, which means they are unable to splice out introns from eukaryotic genes. To engineer a bacterium to produce a eukaryotic protein, it is necessary to synthesize a gene without introns. If you know the nucleotide sequence, you can _____.
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work backward from mRNA to make a version of the gene without introns
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DNA synthesized using an RNA template is called _____.
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cDNA
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Which enzyme makes DNA from an RNA template?
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reverse transcriptase
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What purpose does a nucleic acid probe serve?
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It helps identify genes that have been inserted into bacterial plasmids.
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In which of the following ways are sticky ends and nucleic acid probes alike?
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They both undergo complementary base pairing.
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The production of genetically identical animals that are carrying recombinant human genes for pharmaceutical purposes is called _____.
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pharming
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A eukaryotic gene was inserted into the DNA of a bacterium. The bacterium then transcribed this gene into mRNA and translated the mRNA into protein. The protein produced was useless; it contained many more amino acids than the protein made by the eukaryote. Why?
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The mRNA was not spliced as it is in eukaryotes.
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Cloning human genes into the plasmids of bacteria has enabled scientists to _____.
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use bacteria as "factories" for protein products
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How was the smallpox vaccine produced?
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A harmless variant, a natural mutant, was used to stimulate an immune response.
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Which of the following would be considered a transgenic organism?
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a rat with rabbit hemoglobin genes
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Transgenic organisms are only scientifically or commercially useful if _____.
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the inserted ("foreign") gene is expressed in the host organism
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Genetically modified organisms include microbes that possess enzymes promoting antibiotic resistance. This is a problem that concerns many individuals, with the rise of antibiotic-resistant organisms. However, these organisms do not pose a risk to public health. Why?
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The conditions would be unfavorable to their survival.
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What does the process of gene therapy involve?
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It adds a functioning version of the defective gene to the cells of an individual.
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To date, the "easy" part of gene therapy has been _____.
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isolating and cloning the normal gene
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DNA profiling is a forensic procedure being utilized to identify individuals. This technique _____.
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compares the DNA banding patterns of small segments of the genome
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A genetic marker is a _____.
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particular nucleotide sequence whose inheritance can be followed
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What is the function of the polymerase chain reaction (PCR)?
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It can make a large amount of DNA from a tiny amount.
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What is the purpose of gel electrophoresis?
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It allows for the separation of fragments of DNA.
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DNA profiles utilize _____ DNA sequences.
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short tandem repeat
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Archaeologists unearthed a human skull with a small dried fragment of the scalp still attached. They extracted a tiny amount of DNA from the scalp tissue. To obtain sufficient DNA for an analysis of the ancient human's genes, they could _____.
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use the polymerase chain reaction
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The patterns of bands on DNA profiles are sometimes called genetic fingerprints. Imagine that DNA profiles are used to determine whether Sam could be the father of Becky's baby. Sam is the father if _____ genetic fingerprint shows bands present in _____ genetic fingerprint.
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the baby's ... Sam's and Becky's
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DNA profiles used as evidence in a murder trial look similar to supermarket bar codes. The pattern of bars in a DNA profile shows _____.
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the presence of various-sized fragments of DNA
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Comparison of whole genome sequences shows that we share _____ of our genome sequence with our closest relative.
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96%
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The current estimate for the number of genes in the human genome is about 20,500. Which of the following organisms has almost twice as many genes as humans?
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rice
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Barbara McClintock, a 1983 Nobel Laureate in Physiology or Medicine, found a particular nucleotide sequence that repeated itself on different chromosomes in different mouse skin cells. This supported the idea that _____.
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transposable elements can move around in DNA
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If the human genome is so large, relative to the size of other organisms' genomes, why do we have so few genes?
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We have a lot of "junk" DNA that does not code for anything.
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Celera Genomics implemented a faster way of sequencing the human genome. What was this method?
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shotgun cloning
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The shotgun cloning technique differs from the original method of sequencing the human genome because _____.
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the genetic and physical mapping stages can be skipped
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A particular digestive disorder is noted in members of a family. How would you approach the study of this disorder from a strictly proteomic angle?
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Isolate any food or drink that seems to influence the expression of the gene of interest.
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Analysis of human and Neanderthal DNA have revealed that _____.
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Neanderthals may have had the ability to speak
