3. Please give explanations about how the following examples lead to epigenetics: a. DNA methylation, b. HP1 and c. Prions.

5. David would like to design an expression construct that allows expressions of green fluorescent protein (GFP) and coronavirus spike (S) protein from one single RNA in 293T cells. Please draw a map of this construct and provide the rationale of the construct design, e.g., explain the function of each critical component on this map.