Exam 20: The Molecular Revolution: Biotechnology and Beyond

Use the following information to answer the question(s) below. Six students have taken samples of their own cheek cells, purified the DNA, and used an enzyme (endonuclease) known to cut at zero, one, or two sites in a particular gene of interest. -They might be conducting such an experiment to ________.

What is metagenomics?

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

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

Gene therapy requires ________.

Use the following information to answer the question(s) below. In the textbook you read about the amplification and sequencing of 30,000-year-old Neanderthal DNA to learn that it's unlikely Neanderthals and modern humans interbred. Let's take a closer look at this early work with ancient DNA (M. Krings, A. Stone, R.W. Schmitz, H. Krainitzki, M. Stoneking, and S. Pääbo. 1997. Neanderthal 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 extensive rinsing in distilled water. After removal, the sample was immediately put into a sterile tube for transport to Munich. All subsequent manipulations of the sample, and experimental procedures prior to cycling of PCR reactions, were carried out in laboratories solely dedicated to the analysis of archaeological specimens, where protective clothing, separate equipment and reagents, UV irradiation, and 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 mtDNA 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. -Refer to the paragraphs on the Krings et al. paper. How could the "demographic history of Neanderthal populations" be explored if mitochondrial DNA from other Neanderthal samples could be PCR amplified?

Use the following information to answer the question(s) below. In the textbook you read about the amplification and sequencing of 30,000-year-old Neanderthal DNA to learn that it's unlikely Neanderthals and modern humans interbred. Let's take a closer look at this early work with ancient DNA (M. Krings, A. Stone, R.W. Schmitz, H. Krainitzki, M. Stoneking, and S. Pääbo. 1997. Neanderthal 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 extensive rinsing in distilled water. After removal, the sample was immediately put into a sterile tube for transport to Munich. All subsequent manipulations of the sample, and experimental procedures prior to cycling of PCR reactions, were carried out in laboratories solely dedicated to the analysis of archaeological specimens, where protective clothing, separate equipment and reagents, UV irradiation, and 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 mtDNA 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. -Refer to the paragraph on the Krings et al. paper. Why did the researchers wear protective clothing and note so emphatically that they did so?

Metagenomics aims to learn about the diversity of organisms, particularly microbes that inhabit natural environments. J. Craig Venter, a key figure in the race to obtain the human genome sequence, and his colleagues pioneered this approach in a study that analyzed DNA obtained from microbes collected from the Sargasso Sea, an intensively studied, nutrient-impoverished part of the Caribbean lying to the southeast of Bermuda. (C. J. Venter, K. Remington, J. F. Heidelberg, A. L. Halpern, D. Rusch, J. A. Eisen, D. Wu, I. Paulsen, K. E. Nelson, W. Nelson, D. E. Fouts, S. Levy, A. H. Knap, M. W. Lomas, K. Nealson, O. White, J. Peterson, J. Hoffman, R. Parsons, H. Baden-Tillson, C. Pfannkock, Y.-H. Rogers, and H. O. Smith. 2004. Environmental genome shotgun sequencing of the Sargasso Sea. Science 304:66-74.) -Refer to the paragraph on the Venter et al. paper and the accompanying table. As with many new endeavors, concerns have been raised by some that genomics will fundamentally change the way biological research is practiced. Examine the full citation for the Venter et al. paper and consider the way this work was done. Now think of some seminal works in the history of biology, for example, Darwin's On the Origin of Species and Watson and Crick's publication on DNA structure. What do you think the concern might be that has been voiced about genomics?

Biologists now routinely test for homology between genes in different species. If genes are determined to be homologous, it means that they are related ________.

A laboratory might use dideoxyribonucleotides to ________.

Metagenomics aims to learn about the diversity of organisms, particularly microbes that inhabit natural environments. J. Craig Venter, a key figure in the race to obtain the human genome sequence, and his colleagues pioneered this approach in a study that analyzed DNA obtained from microbes collected from the Sargasso Sea, an intensively studied, nutrient-impoverished part of the Caribbean lying to the southeast of Bermuda. (C. J. Venter, K. Remington, J. F. Heidelberg, A. L. Halpern, D. Rusch, J. A. Eisen, D. Wu, I. Paulsen, K. E. Nelson, W. Nelson, D. E. Fouts, S. Levy, A. H. Knap, M. W. Lomas, K. Nealson, O. White, J. Peterson, J. Hoffman, R. Parsons, H. Baden-Tillson, C. Pfannkock, Y.-H. Rogers, and H. O. Smith. 2004. Environmental genome shotgun sequencing of the Sargasso Sea. Science 304:66-74.) -Refer to the paragraph on the Venter et al. paper and the accompanying table. What practical applications for human society may arise first from this or similar metagenomic studies?

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 that ________.

Which of the following is one of the technical reasons why gene therapy is problematic?

Which of the following is in the correct order for one cycle of polymerase chain reaction (PCR)?

Bioinformatics can be used to scan for short sequences that specify known mRNAs, called ________.

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 the sample with DNA from living birds, which of the following would be most useful for increasing the amount of dodo DNA available for testing?

If you are a human geneticist looking for an ideal population in which to map disease genes, which of the following characteristics would help the mapping study?

The comparison between the number of human genes and those of other animal species has led to many conclusions, including that ________.

What is the difference between a linkage map and a physical map?

If a scientist needs to put new DNA into a bacterium, she must ________ the bacterium.