Chapter 9, Problem 10P

The text stated that molecular biologists have developed elegant techniques that can convert any type of DNA end into any other type of DNA end. In this problem, consider genomic DNA that is broken by mechanical shearing into random pieces. Some of the ends of these pieces are blunt, some have 5′-overhangs, and others have 3′-overhangs.

a.	Must the two ends of any one genomic DNA fragment be of the same type?
b.	Explain why the ends with 5′ or 3′ overhangs are not sticky.
c.	Researchers can convert ends with overhangs into blunt ends using either DNA polymerase (plus the four dNTPs), or nuclease S1, which degrades single-stranded regions of DNA but not doublestranded regions. Which kinds of ends with overhangs (5′ or 3′) could be converted into blunt ends using DNA polymerase? With S1 nuclease?