Exam 12: DNA Technology and Genomics

Which of the following is the best definition of a genomic library?

DNA ligase binds

Gel electrophoresis sorts DNA molecules on the basis of their

The number of proteins in humans

Which of the following has not been a significant issue in the creation of genetically modified (GM)organisms?

Restriction enzymes specifically recognize and cut short sequences of DNA called

You prepare a genomic library and use this as a source to produce recombinant proteins in E. coli. However, after producing the proteins you find that they are all too long or too short. In fact, you don't find a single protein that is the correct size. What is the best explanation for this result?

After reading the paragraphs below, answer the questions that follow. Cystic fibrosis is an autosomal recessive genetic disorder that most severely affects the lungs and respiratory tract. Cystic fibrosis is caused by a mutation in the gene for the protein cystic fibrosis transmembrane regulator (CFTR), which regulates the movement of chloride and sodium ions across epithelial cell membranes. When the CFTR gene is mutated in cystic fibrosis, the defective CFTR protein cannot transport ions properly, which results in too little water drawn across the membrane and the buildup of thick and sticky (viscous) mucus, especially in the airways. This leads to difficulty of breathing and frequent lung infections. Research has shown that some of the increased thickness and viscosity of the mucus in the respiratory tract is due to the presence of human DNA. If DNA is present in high concentrations in solution, the DNA molecules can get entangled and lead to a thick, viscous solution. To combat this, pharmaceutical companies have developed recombinant forms of the human deoxyribonuclease I (DNase I) protein. DNase I, after being translated and modified with sugar groups, is normally produced in human cells and possibly plays a role in DNA breakdown during apoptosis (programmed cell death). -If recombinant DNase I is added to a vial of respiratory secretions from a cystic fibrosis patient, which of the following results would indicate that the recombinant DNase I is functional?

When DNA molecule "A" is cut with the restriction enzyme EcoRI, it is cut into four pieces. When DNA molecule "B," which is exactly identical to DNA molecule "A" except for the presence of one SNP, is cut with EcoRI, it is cut into three pieces. What is the best explanation for this observation?

Approximately what percentage of human DNA is noncoding?

Use the figure below to answer the following question. The bands in the ladder are in 10-base increments, starting with 10 bases at the bottom and going to 70 bases at the top. CS, crime scene; S1, suspect 1; S2, suspect 2; S3, suspect 3. Which suspect is likely to have committed the crime?

Which of the following statements about genomics is false?

You are trying to produce a cDNA library starting from mRNA in skeletal muscle cells. You add the following components to a tube and let the reaction proceed: skeletal muscle mRNA, free nucleotides, and DNA polymerase. After inspecting the products of the reaction, you do not find any cDNA molecules at all. What is the most likely explanation for this result?

The ________ approach to gene cloning employs a mixture of fragments from the entire genome of an organism and results in the production of thousands of different recombinant plasmids.

After reading the paragraphs below, answer the questions that follow. Cystic fibrosis is an autosomal recessive genetic disorder that most severely affects the lungs and respiratory tract. Cystic fibrosis is caused by a mutation in the gene for the protein cystic fibrosis transmembrane regulator (CFTR), which regulates the movement of chloride and sodium ions across epithelial cell membranes. When the CFTR gene is mutated in cystic fibrosis, the defective CFTR protein cannot transport ions properly, which results in too little water drawn across the membrane and the buildup of thick and sticky (viscous) mucus, especially in the airways. This leads to difficulty of breathing and frequent lung infections. Research has shown that some of the increased thickness and viscosity of the mucus in the respiratory tract is due to the presence of human DNA. If DNA is present in high concentrations in solution, the DNA molecules can get entangled and lead to a thick, viscous solution. To combat this, pharmaceutical companies have developed recombinant forms of the human deoxyribonuclease I (DNase I) protein. DNase I, after being translated and modified with sugar groups, is normally produced in human cells and possibly plays a role in DNA breakdown during apoptosis (programmed cell death). -If you wanted to produce a recombinant form of DNase I, what cell type should you use?

The restriction enzyme BamHI recognizes the DNA sequence GGATCC and always cuts between the two G nucleotides. How many bases long is the sticky end of a DNA molecule that has been cut with BamHI?

Which step in the creation of cDNA involves the use of reverse transcriptase?

Which of the following statements about genome sequencing is false?

When plasmids are used to produce a desired protein,

Genomic libraries can be constructed using either bacterial plasmids or what other vector?