2. (The diamond.) The four-node diamond pattern occurs when X regulates Y and Z, and both Y and Z regulate gene W (a) How does the mean number of diamonds scale with network size in random ER networks? (b) What are the distinct types of sign combinations of the diamond (where each arrow is either activation + or repression -)? How many of these are coherent? (c) (Optional) Consider a diamond with four activation arrows. Assign activation thresholds to all arrows. Analyze the dynamics of W following a step of S x, for the AND logic at the W promoter. Are there sign-sensitive delays