1. Explain how the concept of primary productivity gives rise to the idea of bottom up control in ecosystems. Give examples from your studies in ESS of ecosystems that have different levels
of complexity due to differences in primary productivity.

4. multiple crosses were made between true-breeding lines of black and yellow labrador retrievers. all the f1 progeny were black. when these progeny were intercrossed, they produced an f2 consisting of 91 black, 39 yellow and 30 chocolate. a. propose an explanation for the inheritance of coat color in labradors. b. propose a biochemical pathway for coat color determination and indicate how the relevant genes control coat coloration.