Problem:

Answer following questions:

Question 1: With increasing doses of UV exposure, what trend would you expect to see on the yeast plates with regard to survival rates?

Question 2: In terms of proximity to the UV source, how could we alter the procedure of this lab, in order to get more lethality and more mutations on the plates, without changing the length of exposure or the dilutions?

Question 3: UV radiation causes the formation of dimers (covalent bonding between adjacent nucleotides) involving which bases?

Question 4: Describe 2 repair systems which can repair the type of DNA damage described in #3 above, including how each system works, including the names of any enzymes and how they act to repair the damage.

Question 5: We plated an ade- strain and exposed the cells to UV. What is the genotype and phenotype of the resulting yeast colonies which we counted as "mutants" (in step 3 of the procedure), if the mutation event was a true reversion?

Please provide discription of all the answers.