Genetics: Analysis and Principles 5th Edition by Robert Brooker

Exercise 34

Consider how histone proteins bind to DNA and then explain why a high salt concentration can remove histones from DNA (as shown in Figure 10.19b).FIGURE 10.19 The importance of histone proteins and scaffolding proteins in the compaction of eukaryotic chromosomes. (a) A metaphase chromosome. (b) A metaphase chromosome following treatment with high salt concentration to remove the histone proteins. The black arrow on the right points to an elongated strand of DNA. The white arrow on the left points to the scaffold (composed of nonhistone proteins), which anchors the bases of the radial loops. As shown earlier in Figure 10.18d, this scaffold contains protein filaments.
a.
FIGURE 10.18 The steps in eukaryotic chromosomal compaction leading to the metaphase chromosome.