1. a.Describe in detail how a direct DNA repair mechanism works.
b.Can you think of a way in which you could inhibit this repair mechanism in bacteria that have been exposed to UV radiation?
2. For each of the following, give a brief description:
a.DNA exonuclease
b.AP site
c.DNA ligase
d.post replication repair
3. a.What is cancer? Include in your answer a description of oncogenes.
b.Explain how a mutated DNA repair gene could lead to a cancer.
c.If a mutation occurs in a gene in a skin cell, describe two possible outcomes for the future of that cell.
4.a.What is a retrovirus?
b.How can a retrovirus cause the transformation of a normal cell into a cancer cell?
c.What is a transforming retrovirus and how does it cause cancer?
5.a.What is a transposon? In you answer include two distinguishing features of a transposon.
b.What is meant by conservative and replicate transfer?
c.Briefly describe the mechanism of action of the Ds and Ac transposons as discovered in maize by McClintock.