1. The diagram below shows the DNA elements and associated factors that comprise the lac operon. Examine the diagram and answer the questions below

a) List all the elements in this piece of DNA that act in cis.

b) List all the elements in this piece of DNA that act in trans?

c) Where would the mutation occur in the IS situation? Would the IS mutation act in cis or in trans?

2. Epigenetic tags turn genes on or off in response to cell signals, creating a dynamic layer of control called the epigenome. Do you expect the epigenome of a kidney cell and a brain cell to be the same? Different? Explain. How about the epigenome of a newborn brain cell and the corresponding brain cell of their parent?

3. Comparative genome analyses reveal a surprising constancy in genetic content: vertebrate genomes have only about twice the number of genes that invertebrate genomes have, and the increase is primarily due to the duplication of existing genes rather than the invention of new ones. How, then, has evolutionary diversity arisen? Comment on these observations.