1. Copyright © 2009 Pearson Education, Inc. Chapter 12 DNA Organization in Chromosomes Copyright © 2009 Pearson Education, Inc.

2. Single nucleic acid molecule No proteins DNA or RNA Single or double stranded Circular or linear Packed into a small volume Viral Genetic Material

3. Copyright © 2009 Pearson Education, Inc. Single nucleic acid molecule Some proteins Always double stranded DNA Large, circular chromosome Packed into a small volume (nucleoid region) Bacterial Genetic Material

4. Copyright © 2009 Pearson Education, Inc. Table 12.1

5. Copyright © 2009 Pearson Education, Inc. Figure 12.2

6. Copyright © 2009 Pearson Education, Inc. Figure 12.3

7. Copyright © 2009 Pearson Education, Inc. Figure 12.4 Supercoiling

8. Copyright © 2009 Pearson Education, Inc. Polytene chromosomes Lamp brush chromosomes Specialized Eukaryotic Chromosome Organizations

9. Copyright © 2009 Pearson Education, Inc. Figure 12.5 Polytene

10. Copyright © 2009 Pearson Education, Inc. Figure 12.6 Polytene

11. Copyright © 2009 Pearson Education, Inc. Figure 12.7 Lamp Brush

12. Copyright © 2009 Pearson Education, Inc. Only visible during mitosis Easier to move DNA around Normally uncoiled and dispersed Chromatin Available for genetic activity Eukaryotic Chromosomes

13. Copyright © 2009 Pearson Education, Inc. DNA has a substantial amount of associated proteins Histones Non-histones Chromatin

14. Copyright © 2009 Pearson Education, Inc. Table 12.2

15. Copyright © 2009 Pearson Education, Inc. Figure 12.8

16. Copyright © 2009 Pearson Education, Inc. Figure 12.9

17. Copyright © 2009 Pearson Education, Inc. Highly folded DNA presents a problem – genes are inaccessible High resolution images showed how chromatin could be remodeled Histone tails Remodeling Acetylations Methylation Phosphorylation Chromatin Remodeling

18. Copyright © 2009 Pearson Education, Inc. Figure 12.10

19. Copyright © 2009 Pearson Education, Inc. Euchromatin Light staining Active genes Uncoiled during interphase Heterochromatin Heavy staining No (few) active genes Tightly packed during interphase Euchromatin vs Heterochromatin

20. Copyright © 2009 Pearson Education, Inc. Enabled further characterization of chromosomes (previously only size) C – banding Centromeres stain darkly G – banding Digest with trypsin before staining Banding Patterns

21. Copyright © 2009 Pearson Education, Inc. Figure 12.11 C – Banding

22. Copyright © 2009 Pearson Education, Inc. Figure 12.12 G – Banding

23. Copyright © 2009 Pearson Education, Inc. Figure 12.13 X chromosome banding pattern

24. Copyright © 2009 Pearson Education, Inc. Satellite DNA Centromeric sequences Telomeric sequences Middle (moderate) repetitive DNA VNTRs STRs Transposable sequences Pseudogenes Repetitive Sequences

25. Copyright © 2009 Pearson Education, Inc. Figure 12.15 Satellite DNA

26. Copyright © 2009 Pearson Education, Inc. Figure 12.16 Satellite DNA

27. Copyright © 2009 Pearson Education, Inc. Figure 12.17 Centromeric Sequences