Walking home from work late one night, jaydra suddenly hears footsteps behind her. her heart pounds, her muscles tense, and her mouth goes dry. these bodily responses are activated by her nervous system.

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.