Chapter 20

Level 1: Knowledge/Comprehension 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.

Level 1: Knowledge/Comprehension 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

Level 1: Knowledge/Comprehension 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.

Level 1: Knowledge/Comprehension 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

Level 1: Knowledge/Comprehension 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

Level \(2 :\) Application/Analysis 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.

Level \(2 :\) Application/Analysis 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.

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

Level 3: Synthesis/Evaluation MAKE CONNECTIONS Imagine you want to study one of the human crystallins, proteins present in the lens of the eye (see Figure 1.8). To obtain a sufficient amount of the protein of interest, you decide to clone the gene that codes for it. Assume you know the sequence of this gene. Explain how you would go about this.

Level 3: SynthesislEvaluation Evoution connection Ethical considerations aside, if DNA-based technologies became widely used, discuss how they might change the way evolution proceeds, as compared with the natural evolutionary mechanisms that have operated for the past 4 billion years.

Level 3: SynthesislEvaluation SCIENTIFIC INQUIRY You hope to study a gene that codes for a neurotransmitter protein produced in human brain cells. You know the amino acid sequence of the protein. Explain how you might (a) identify what genes are expressed in a specific type of brain cell, (b) Identify (and isolate) the neurotransmitter gene, (c) produce multiple copies of the gene for study, and (d) produce large quantities of the neurotransmitter for evaluation as a potential medication.

Level 3: SynthesislEvaluation WRITE ABOUT A THEME: INFORMATION In a short essay \((100-150\) words), discuss how the genetic basis of life plays a central role in biotechnology.

Level 3: SynthesislEvaluation SYNTHESIZE YOUR KNOWLEDGE The water in the Yellowstone National Park hot springs shown here is around \(160^{\circ} \mathrm{F}\) \(\left(70^{\circ} \mathrm{C}\right) .\) Biologists assumed that no species of organisms could live in water above about \(130^{\circ} \mathrm{F}\left(55^{\circ} \mathrm{C}\right),\) so they were surprised to find several species of bacteria there, now called thermophiles ("heat-lovers"). You've learned in this chapter how an enzyme from one species, Thermus aquaticus, made feasible one of the most important DNA-based techniques used in labs today. Identify the enzyme, and indicate the value of its being isolated from a thermophile. Suggest other reasons why enzymes from this bacterium (ot other thermophiles) might also be valuable.