Becker's World of the Cell 9th Edition by Lewis Kleinsmith, Jeff Hardin, Gregory Paul Bertoni

Exercise 8

Apoptosis and DNA. When cells undergo apoptosis, their DNA becomes fragmented. When the DNA is run out on a gel, the

resulting fragments differ in size by a standard amount, about 200 bp, so that the resulting separated DNA has a characteristic "ladder " appearance (Figure 24-30 ). Explain why this pattern of DNA fragments is obtained, based on what you know about eukaryotic chromatin.