1. LS1B Section One

2. Schedule • Introductions/Attendance • Pre-lab Quiz • Section Overview/Policies • Yeast Complementation Review • Yeast Complementation Lab Work • Review Practice Problems • Mitosis Review • Mitosis Lab Work • Clean up

3. Yeast Complementation What is Yeast?

4. Yeast Complementation

5. Yeast Complementation Why? What are we trying to find out? • For six mutant strains,which step (enzyme) in the histidine pathway is disrupted? • Same step or different steps between the different strains?

6. Yeast Complementation What do we already know? • None of them can grow without histidine (ie they can’t make it themselves) • They are of mating type α

7. Yeast Complementation What do we have? • Six other strains in which the histidine pathway is also disrupted but we know which step (enzyme)! • They are of mating type a

8. Yeast Complementation • What to do? • Mate the ones with unknown mutations (α) with those with known mutations (a). Growth without Histidine • If we see growth: different genes (enzymes, steps in the histidine pathway) • If we don’t see growth: same gene (enzyme, step in the histidine pathway)

9. Yeast Complementation • What we are going to do today • Streak out known and unknown HIS- mutants Why? Allow us to mate them in grid pattern next week

10. Schedule • Introductions/Attendance • Pre-lab Quiz • Section Overview/Policies • Yeast Complementation Review • Yeast Complementation Lab Work • Review Practice Problems • Mitosis Review • Mitosis Lab Work • Clean up

11. Mitosis Interphase Uncondensed chromosomes replicate

12. Mitosis Prophase Chromosomes condense and move towards metaphase plate

13. Mitosis Metaphase Chromosomes line up on metaphase plate

14. Mitosis Anaphase Sister chromatids separate

15. Mitosis Telophase Chromosomes finish moving to opposite sites

16. Mitosis Cytokinesis then Interphase

17. Mitosis

18. Mitosis

19. Schedule • Introductions/Attendance • Pre-lab Quiz • Section Overview/Policies • Yeast Complementation Review • Yeast Complementation Lab Work • Review Practice Problems • Mitosis Review • Mitosis Lab Work • Clean up

20. Clean Up • Gas off, Bunsen burner disconnected • All streaked plates labeled, taped, in drawer • All slides in glass disposal • Remaining tooth picks up at front on red tray • Microscopes turned off, unplugged • Cameras labeled with names and put on front desk • Stain, unused slides, unused coverslips, remaining onion, tweezers, scissors, probe, etc at front of room on or near red tray • Carnoy and HCL left on desk top • Desktops wiped down, chairs pushed in THANK YOU!!