Copyright © 2009 Pearson Education, Inc. Active Lecture Questions for Biology: Concepts & Connections, Sixth Edition Campbell, Reece, Taylor, Simon, and Dickey Chapter 12 DNA Technology and Genomics

Copyright © 2009 Pearson Education, Inc. Concept Check Restriction enzymes are useful tools for cutting DNA fragments. What is the function of restriction enzymes in their normal bacterial environment? 1)Restriction enzymes remove and recycle old mRNA’s. 2)Restriction enzymes cut up DNA taken from the environment and used as a nutrient source. 3)Restriction enzymes remove the excess DNA that results from DNA replication. 4)Restriction enzymes cut invading viral DNA sequences at specific sequences disrupting the viral DNA genes.

Copyright © 2009 Pearson Education, Inc. Answer Restriction enzymes are useful tools for cutting DNA fragments. What is the function of restriction enzymes in their normal bacterial environment? 4)Restriction enzymes cut invading viral DNA sequences at specific sequences disrupting the viral DNA genes.

Copyright © 2009 Pearson Education, Inc. Concept Check PCR or polymerase chain reaction amplifies target DNA fragments. This technique takes place outside of a cell and uses heat to separate the double stranded DNA along with which of the following? 1)Restriction enzymes from E. coli bacteria 2)DNA polymerase isolated from bacteria from hot springs 3)Radioactive probes 4)Plasmids from E. coli or other bacteria

Copyright © 2009 Pearson Education, Inc. Answer PCR or polymerase chain reaction amplifies target DNA fragments. This technique takes place outside of a cell and uses heat to separate the double stranded DNA along with which of the following? 2)DNA polymerase isolated from bacteria from hot springs

Copyright © 2009 Pearson Education, Inc. Interpreting Data The image to the right represents a simulated electrophoresis gel run of a restriction analysis of λ virus DNA. Both EcoR1 (E) and BamH1 (B) cut λ DNA into 6 fragments. Why aren’t the fragments aligned together on the gel? 1)The enzymes cut at random sites each time. 2)The enzymes each cut at unique restriction sites that create differently sized fragments. 3)The two enzymes create equal sized fragments but the gel cannot resolve the difference.

Copyright © 2009 Pearson Education, Inc. Answer The image to the right represents a simulated electrophoresis gel run of a restriction analysis of λ virus DNA. Both EcoR1 (E) and BamH1 (B) cut λ DNA into 6 fragments. Why aren’t the fragments aligned together on the gel? 2)The enzymes each cut at unique restriction sites that create differently sized fragments.

Copyright © 2009 Pearson Education, Inc. Interpreting Data The fourth column (H) is λ DNA cut with HindIII enzyme. It serves as a ruler to estimate the size of the other fragments. How long (in base pairs) do you estimate the shortest EcoR1 (E) fragment to be? 1)2000 bp 2)2300 bp 3)3500 bp 4)4300 bp

Copyright © 2009 Pearson Education, Inc. Answer The fourth column (H) is λ DNA cut with HindIII enzyme. It serves as a ruler to estimate the size of the other fragments. How long (in base pairs) do you estimate the shortest EcoR1 (E) fragment to be? 3)3500 bp

Copyright © 2009 Pearson Education, Inc. Interpreting Data The third column was loaded with λ DNA that was cut with both EcoR1 and BamH1 enzymes together. This creates a number of additional fragments. Which EcoR1 fragment does not have a BamH1 cut site? 1)The first fragment from the top. (the largest) 2)The second fragment from the top. 3)The second to the bottom fragment. 4)The bottom fragment. (the smallest)

Copyright © 2009 Pearson Education, Inc. Answer The third column was loaded with λ DNA that was cut with both EcoR1 and BamH1 enzymes together. This creates a number of additional fragments. Which EcoR1 fragment does not have a BamH1 cut site? 4)The bottom fragment. (the smallest)

Copyright © 2009 Pearson Education, Inc. Biology and Society This is a DNA microarray—an incredibly powerful tool to explore gene expression in cells. Microarrays also have the potential to be used to diagnose and predict the onset of debilitating diseases such as cancer. There is much promise for this technology but who has access to this information? Assume that the technology exists today that could screen your specific DNA genome for cancer risk. In this scenario do you think that insurance companies would be justified requiring a DNA screen for cancer upon application for health or life insurance?

Copyright © 2009 Pearson Education, Inc. Biology and Society Do you think that states should create and maintain DNA databases similar to fingerprint databases? DNA technology has revolutionized forensic science. Some states have required DNA samples for all convicted felons. Some consider this to be an infringement on personal rights and freedoms. Several unsolved cases have been solved with this type of evidence and some convicted persons have been exonerated with DNA evidence.

Copyright © 2009 Pearson Education, Inc. Biology and Society Do you think food products that are produced from GM organisms should be labeled to inform consumers? Do a web-search on “Golden Rice” and you’ll be astounded at the diversity of opinion and information on this particular genetically modified organism (GM). Agricultural scientists are increasingly turning to genetic engineering to develop new crop solutions and yet around the world GM crops are not universally accepted.