1. Chapter 16 Molecular Basis of Inheritance

2. Brainstorm What have we already learned about DNA this semester?

3. Discoveries about DNA Griffith (1928) – Figure 16.2

4. Discoveries about DNA Hershey and Chase (1952) – Figure 16.4

5. Discoveries about DNA Watson and Crick (1953) – Figure 16.1

6. Discoveries about DNA (Watson and Crick continued) - Rosalind Franklin Figure 16.6

7. Discoveries about DNA (Watson and Crick continued) Figure 16.7

8. Discoveries about DNA (Watson and Crick continued) Figure 16.7

9. Replication Purpose – to make an exact copy of a DNA molecule Occurs in nucleus Semi-conservative replication – Figure 16.9

10. Replication Getting Started: Origin of replication – - Bacteria Figure 16.12a

11. Replication (Getting Started continued) (Origin of replication continued) - Eukaryotes Figure 16.12b

12. Replication (Getting Started continued) 1. Helicase untwists the double helix. 2. Single-stranded binding proteins stabilize the single strands. 3. Primase makes primer out of RNA nucleotides.

13. Replication (Getting Started continued) Figure 16.13

14. Replication Synthesis of leading strand: 1. DNA polymerase III adds next complementary nucleotide to the primer. Figure 16.14

15. Replication (Leading strand continued) 2. DNA pol III moves along the template strand, adding the correct nucleotide one at a time. Figure 16.15

16. Replication Synthesis of lagging strand: 1. DNA pol III adds complementary nucleotides to the primer. - Okasaki fragments 2. DNA pol I replaces the RNA in primer with DNA nucleotides. 3. DNA ligase joins Okasaki fragments together in a continuous strand.

17. Replication (Synthesis of lagging strand continued) Figure 16.16

18. Replication Now have 2 identical DNA molecules! Figure 16.17 The End:

19. Replication Figure 16.18 BioFlix: DNA Replication BioFlix: DNA Replication

20. DNA Proofreading & Repair DNA polymerases Mismatch repair enzymes Nuclease Figure 16.19

21. Replicating the Ends of DNA Figure 16.20

22. Replicating the Ends of DNA Telomeres – Telomerase – Figure 16.21

23. Chromatin Packing Double Helix – Histones – Nucleosomes – Chromatin – Looped domains – Chromosome –

24. Chromatin Packing Figure 16.22

25. Chromatin Packing EXPLAIN this concept to a classmate.

26. **Take Away Concept** Our knowledge of DNA molecules is easily taken for granted, but it was hard-earned. This amazing molecule is the foundation for every single living organism, both as individuals and as species.