Summarize the arguments for and against patenting genetically modified organisms.

Injection of double-stranded RNA can lead to gene silencing by degradation of RNA molecules complementary to either strand of the dsRNA. Could RNAi (see Sections 13.3 and 14.3) be used in gene therapy for a defect caused by a recessive allele? A dominant allele? If so, what might be the major obstacle to using RNAi as a therapeutic agent?

What are some of the impacts of biotechnology on crop plants in the United States?

Compare and contrast methods for making transgenic plants and transgenic Drosophila.

It is often desirable to insert cDNAs into a cloning vector in such a way that all the cDNA clones will have the same orientation with respect to the sequences of the plasmid. This is referred to as directional cloning. Outline how you would directionally clone a cDNA library in the plasmid vector pUC18.

A major advance in the 1980s was the development of technology to synthesize short oligonucleotides. This work both facilitated DNA sequencing and led to the advent of the development of PCR. Recently, rapid advances have occurred in the technology to chemically synthesize DNA, and sequences up to 10 kb are now readily produced. As this process becomes more economical, how will it affect the gene-cloning approaches outlined in this chapter? In other words, what types of techniques does this new technology have potential to supplant, and what techniques will not be affected by it?

The bacteriophage lambda genome can exist in either a linear form (see Figures 15.1 and 15.8) or a circular form.How many fragments will be formed by restriction enzyme digestion with XhoI alone, with XbaI alone, and with both XhoI and XbaI in the linear and circular forms of the lambda genome?