Chapter 20, Problem 1PDQ

HOW DO WE KNOW? In this chapter we focused on how specific DNA sequences can be copied, identified, characterized, and sequenced. At the same time, we found many opportunities to consider the methods and reasoning underlying these techniques. From the explanations given in the chapter, what answers would you propose to the following fundamental questions?

1. (a) In a recombinant DNA cloning experiment, how can we determine whether DNA fragments of interest have been incorporated into plasmids and, once host cells are transformed, which cells contain recombinant DNA?
2. (b) What steps make PCR a chain reaction that can produce millions of copies of a specific DNA molecule in a matter of hours without using host cells?
3. (c) How has DNA-sequencing technology evolved in response to the emerging needs of genome scientists?
4. (d) How can gene knockouts, transgenic animals, and gene editing techniques be used to explore gene function?