1. Explain why a gain of function would be a dominant effect and a loss of function would be a recessive effect. Which types of genes are each associated with: oncogenes or defective tumour suppressor genes? Why?
2. What negative role does the environment play in causing cancer? What positive effects can the environment have?
3. Identify four naturally occurring enzymes important to DNA technologies, and describe an example for each of their natural and technological uses.